p block elements 1
TRANSCRIPT
P block elements
Introduction In p-block elements the last
electron enters the outermost p orbital
As we know that the number of p orbitals is three and therefore the maximum number of electrons that can be accommodated in a set of p orbitals is six
There are six groups of pndashblock elements in the periodic table numbering from 13 to 18
It is interesting to note that the non-metals and metalloids exist only in the p-block of the periodic table
The non-metallic character of elements decreases down the group
In fact the heaviest element in each p-block group is the most metallic in nature
Positon of p block element
P block elements
THIS GROUP ELEMENTS SHOW A WIDE VARIATION IN PROPERTIES
BORON IS A TYPICAL NON-METAL ALUMINUM IS A METAL BUT SHOWS MANY CHEMICAL SIMILARITIES TO BORON AND GALLIUM INDIUM AND THALLIUM ARE ALMOST EXCLUSIVELY METALLIC IN CHARACTER
General electronic configuration
The general electronic configuration of element is ns2 np1 to ns2 np6 hence there are 6 families in p block elements
Non metallic character decreases down the group
Boron family- ns2 np1
Carbon family- ns2 np2
Nitrogen family ndash ns2 np3
Oxygen family ndash ns2np4
Halogen family- ns2np5
Noble gas- ns2np6
Group 13 elements
The boron family
Electronic configuration The outer electronic configuration
of these elements is ns2np1 A close look at the electronic
configuration suggests that while boron and aluminum have noble gas core gallium and indium have noble gas plus 10 d-electrons and thallium has noble gas plus 14 f- eacutelectrons plus 10 d-eacutelectron coreacutes
Electronic configuration of 13 grp element
Occurrence Boron is a fairly rare element mainly
occurs as I orthoboric acidII (H3BO3) boraxIIINa2B4O7middot10H2O andIV kernite Na2B4O7middot4H2O In India borax occurs in Puga Valley
(Ladakh)and Sambhar Lake (Rajasthan)
The abundance of boron in earth crust is less than00001 by mass
There are two isotopic forms of boron 10B (19) and 11B (81)
Aluminum is the most abundant metal and the third most abundant element in the earthrsquos crust (83 by mass) after oxygen (455) and Si (277) Bauxite Al2O3 2H2O and cryolite Na3AlF6 are the important minerals of aluminum
In India it is found as mica (KAL3Si3O10(OH)2)in Madhya Pradesh Karnataka Orissa and Jammu
Gallium indium and thallium are less
abundant elements in nature
114 VARIATION IN PROPERTIES
ATOMIC RADII MOVING down the group for each
successive element one extra shell is added hence the atomic radius is expected to increase But one can notice a deviation Atomic radius of Ga(135pm) is less than that of Al(143pm)
This is because of variation in inner core of electronic configuration The atomic radius of Ga is less than Al because of its poor screening effect
Saanika 114 to 116
ALUMINUM 13
GALLIUM31
IONIZATION ENTHALPY (IE or H) Ionization enthalpy also shows irregular
trends On moving down the group IE decreases from B to Al but the next element Ga has slightly higher ionization enthalpy than Al due to the poor shielding of intervening d-electrons It again decreases in and then increases in the last element
ELECTRONEGATIVITY Down the group the
electronegativity decreases from B to Al and then increases marginally This is due to the noticeable difference in atomic size of elements
ELEMENT ATOMIC RADIUSpm ELECTRONEGATIVITY
B 88 20Al 143 15
Ga 135 16In 167 17Tl 170 18
INERT PAIR EFFECT The phenomenon of electrons remaining
paired in valance shell is called inert pair effect
It is the reluctance of the s-electron of the valance shell to take part in bonding It occurs due to poor or ineffective shielding of the ns2 ndash electrons of the valance shell by intervening d and f ndash electrons It increases down the group and thus the lower elements of the group exhibit lower oxidation states
OXIDATION STATES B and Al show oxidation states of +3 only
while Ga In and Tl exhibit oxidation states of both +1 and +3
As we move down in the group 13 due to inert pair effect the tendency to exhibit +3 oxidation states decreases and the tendency to attain +1 oxidation states increases
Stability of +1 oxidation state follows the order GaltInltTl
FB F
F+ NH3
FB
FF
NH3
LEWIS ACIDS Boron trifluoride is trivalent molecule of boron
The number of electrons around central boron atom in this molecule is only six It has incomplete octet Therefore this is electron deficient molecule and has tendency to accept lone pair of electrons to achieve stable inert gas electronic configuration Thus it behaves as Lewis acid
Stability in AlCl3 is formed due to the formation of dimer
Dimer It is a molecule or molecular complex consisting of two identical molecules linked together
Al AlCl
Cl
Cl
Cl
Cl
Cl
206pm221pm
101 7
9118
115 CHEMICAL REACTIVITY Action of Air (oxygen) Amorphous Boron
on heating in air forms B2O3 boron oxide eg 4B + 3O2 1000K 2B2O3
Boron trioxide Reactivity towards Halogens Boron reacts
with halogen to form Trihalides eg 2B+ 3Cl2 2BCl3 Boron trichloride
Reactivity towards Water Pure boron does not react with water Aluminum decomposes boiling water evolving hydrogen
eg 2Al + 6 H2O 2Al(OH)3 + 3H2
Gallium and Indium are not attacked
by pure cold or hot water Thallium is a little more reactive than Gallium and forms an oxide on the surface
116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON) Boron is a nonmetal while other members
are metals Boron shows allotropy while other
members do not Amongst the elements of group 13 boron
has highest MP and BP Boron forms only covalent
compounds(maximum covalence of boron is 3) while other members form both ionic and covalent compounds
Oxides and hydroxides of boron are weakly acidic of aluminium are amphoteric while those of rest of members are most basic
Boron hydride is quite stable while hydrides of other elements are less stable
Only boron combines with active metals such as Mg to form borides while rest of the members do not
3Mg + 2B Mg3B2
Magnesium BorideCrystalline boron is unreactive
973K
Boron with alkaliBoron dissolves with alkali to give
borates with evolution of H2 gas2B + 6NaOH 2Na3BO3+3H2
Reaction with acids-2B + 3HNO3 H3BO3+3NO2
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
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FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Occurrence Boron is a fairly rare element mainly
occurs as I orthoboric acidII (H3BO3) boraxIIINa2B4O7middot10H2O andIV kernite Na2B4O7middot4H2O In India borax occurs in Puga Valley
(Ladakh)and Sambhar Lake (Rajasthan)
The abundance of boron in earth crust is less than00001 by mass
There are two isotopic forms of boron 10B (19) and 11B (81)
Aluminum is the most abundant metal and the third most abundant element in the earthrsquos crust (83 by mass) after oxygen (455) and Si (277) Bauxite Al2O3 2H2O and cryolite Na3AlF6 are the important minerals of aluminum
In India it is found as mica (KAL3Si3O10(OH)2)in Madhya Pradesh Karnataka Orissa and Jammu
Gallium indium and thallium are less
abundant elements in nature
114 VARIATION IN PROPERTIES
ATOMIC RADII MOVING down the group for each
successive element one extra shell is added hence the atomic radius is expected to increase But one can notice a deviation Atomic radius of Ga(135pm) is less than that of Al(143pm)
This is because of variation in inner core of electronic configuration The atomic radius of Ga is less than Al because of its poor screening effect
Saanika 114 to 116
ALUMINUM 13
GALLIUM31
IONIZATION ENTHALPY (IE or H) Ionization enthalpy also shows irregular
trends On moving down the group IE decreases from B to Al but the next element Ga has slightly higher ionization enthalpy than Al due to the poor shielding of intervening d-electrons It again decreases in and then increases in the last element
ELECTRONEGATIVITY Down the group the
electronegativity decreases from B to Al and then increases marginally This is due to the noticeable difference in atomic size of elements
ELEMENT ATOMIC RADIUSpm ELECTRONEGATIVITY
B 88 20Al 143 15
Ga 135 16In 167 17Tl 170 18
INERT PAIR EFFECT The phenomenon of electrons remaining
paired in valance shell is called inert pair effect
It is the reluctance of the s-electron of the valance shell to take part in bonding It occurs due to poor or ineffective shielding of the ns2 ndash electrons of the valance shell by intervening d and f ndash electrons It increases down the group and thus the lower elements of the group exhibit lower oxidation states
OXIDATION STATES B and Al show oxidation states of +3 only
while Ga In and Tl exhibit oxidation states of both +1 and +3
As we move down in the group 13 due to inert pair effect the tendency to exhibit +3 oxidation states decreases and the tendency to attain +1 oxidation states increases
Stability of +1 oxidation state follows the order GaltInltTl
FB F
F+ NH3
FB
FF
NH3
LEWIS ACIDS Boron trifluoride is trivalent molecule of boron
The number of electrons around central boron atom in this molecule is only six It has incomplete octet Therefore this is electron deficient molecule and has tendency to accept lone pair of electrons to achieve stable inert gas electronic configuration Thus it behaves as Lewis acid
Stability in AlCl3 is formed due to the formation of dimer
Dimer It is a molecule or molecular complex consisting of two identical molecules linked together
Al AlCl
Cl
Cl
Cl
Cl
Cl
206pm221pm
101 7
9118
115 CHEMICAL REACTIVITY Action of Air (oxygen) Amorphous Boron
on heating in air forms B2O3 boron oxide eg 4B + 3O2 1000K 2B2O3
Boron trioxide Reactivity towards Halogens Boron reacts
with halogen to form Trihalides eg 2B+ 3Cl2 2BCl3 Boron trichloride
Reactivity towards Water Pure boron does not react with water Aluminum decomposes boiling water evolving hydrogen
eg 2Al + 6 H2O 2Al(OH)3 + 3H2
Gallium and Indium are not attacked
by pure cold or hot water Thallium is a little more reactive than Gallium and forms an oxide on the surface
116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON) Boron is a nonmetal while other members
are metals Boron shows allotropy while other
members do not Amongst the elements of group 13 boron
has highest MP and BP Boron forms only covalent
compounds(maximum covalence of boron is 3) while other members form both ionic and covalent compounds
Oxides and hydroxides of boron are weakly acidic of aluminium are amphoteric while those of rest of members are most basic
Boron hydride is quite stable while hydrides of other elements are less stable
Only boron combines with active metals such as Mg to form borides while rest of the members do not
3Mg + 2B Mg3B2
Magnesium BorideCrystalline boron is unreactive
973K
Boron with alkaliBoron dissolves with alkali to give
borates with evolution of H2 gas2B + 6NaOH 2Na3BO3+3H2
Reaction with acids-2B + 3HNO3 H3BO3+3NO2
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Aluminum is the most abundant metal and the third most abundant element in the earthrsquos crust (83 by mass) after oxygen (455) and Si (277) Bauxite Al2O3 2H2O and cryolite Na3AlF6 are the important minerals of aluminum
In India it is found as mica (KAL3Si3O10(OH)2)in Madhya Pradesh Karnataka Orissa and Jammu
Gallium indium and thallium are less
abundant elements in nature
114 VARIATION IN PROPERTIES
ATOMIC RADII MOVING down the group for each
successive element one extra shell is added hence the atomic radius is expected to increase But one can notice a deviation Atomic radius of Ga(135pm) is less than that of Al(143pm)
This is because of variation in inner core of electronic configuration The atomic radius of Ga is less than Al because of its poor screening effect
Saanika 114 to 116
ALUMINUM 13
GALLIUM31
IONIZATION ENTHALPY (IE or H) Ionization enthalpy also shows irregular
trends On moving down the group IE decreases from B to Al but the next element Ga has slightly higher ionization enthalpy than Al due to the poor shielding of intervening d-electrons It again decreases in and then increases in the last element
ELECTRONEGATIVITY Down the group the
electronegativity decreases from B to Al and then increases marginally This is due to the noticeable difference in atomic size of elements
ELEMENT ATOMIC RADIUSpm ELECTRONEGATIVITY
B 88 20Al 143 15
Ga 135 16In 167 17Tl 170 18
INERT PAIR EFFECT The phenomenon of electrons remaining
paired in valance shell is called inert pair effect
It is the reluctance of the s-electron of the valance shell to take part in bonding It occurs due to poor or ineffective shielding of the ns2 ndash electrons of the valance shell by intervening d and f ndash electrons It increases down the group and thus the lower elements of the group exhibit lower oxidation states
OXIDATION STATES B and Al show oxidation states of +3 only
while Ga In and Tl exhibit oxidation states of both +1 and +3
As we move down in the group 13 due to inert pair effect the tendency to exhibit +3 oxidation states decreases and the tendency to attain +1 oxidation states increases
Stability of +1 oxidation state follows the order GaltInltTl
FB F
F+ NH3
FB
FF
NH3
LEWIS ACIDS Boron trifluoride is trivalent molecule of boron
The number of electrons around central boron atom in this molecule is only six It has incomplete octet Therefore this is electron deficient molecule and has tendency to accept lone pair of electrons to achieve stable inert gas electronic configuration Thus it behaves as Lewis acid
Stability in AlCl3 is formed due to the formation of dimer
Dimer It is a molecule or molecular complex consisting of two identical molecules linked together
Al AlCl
Cl
Cl
Cl
Cl
Cl
206pm221pm
101 7
9118
115 CHEMICAL REACTIVITY Action of Air (oxygen) Amorphous Boron
on heating in air forms B2O3 boron oxide eg 4B + 3O2 1000K 2B2O3
Boron trioxide Reactivity towards Halogens Boron reacts
with halogen to form Trihalides eg 2B+ 3Cl2 2BCl3 Boron trichloride
Reactivity towards Water Pure boron does not react with water Aluminum decomposes boiling water evolving hydrogen
eg 2Al + 6 H2O 2Al(OH)3 + 3H2
Gallium and Indium are not attacked
by pure cold or hot water Thallium is a little more reactive than Gallium and forms an oxide on the surface
116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON) Boron is a nonmetal while other members
are metals Boron shows allotropy while other
members do not Amongst the elements of group 13 boron
has highest MP and BP Boron forms only covalent
compounds(maximum covalence of boron is 3) while other members form both ionic and covalent compounds
Oxides and hydroxides of boron are weakly acidic of aluminium are amphoteric while those of rest of members are most basic
Boron hydride is quite stable while hydrides of other elements are less stable
Only boron combines with active metals such as Mg to form borides while rest of the members do not
3Mg + 2B Mg3B2
Magnesium BorideCrystalline boron is unreactive
973K
Boron with alkaliBoron dissolves with alkali to give
borates with evolution of H2 gas2B + 6NaOH 2Na3BO3+3H2
Reaction with acids-2B + 3HNO3 H3BO3+3NO2
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
114 VARIATION IN PROPERTIES
ATOMIC RADII MOVING down the group for each
successive element one extra shell is added hence the atomic radius is expected to increase But one can notice a deviation Atomic radius of Ga(135pm) is less than that of Al(143pm)
This is because of variation in inner core of electronic configuration The atomic radius of Ga is less than Al because of its poor screening effect
Saanika 114 to 116
ALUMINUM 13
GALLIUM31
IONIZATION ENTHALPY (IE or H) Ionization enthalpy also shows irregular
trends On moving down the group IE decreases from B to Al but the next element Ga has slightly higher ionization enthalpy than Al due to the poor shielding of intervening d-electrons It again decreases in and then increases in the last element
ELECTRONEGATIVITY Down the group the
electronegativity decreases from B to Al and then increases marginally This is due to the noticeable difference in atomic size of elements
ELEMENT ATOMIC RADIUSpm ELECTRONEGATIVITY
B 88 20Al 143 15
Ga 135 16In 167 17Tl 170 18
INERT PAIR EFFECT The phenomenon of electrons remaining
paired in valance shell is called inert pair effect
It is the reluctance of the s-electron of the valance shell to take part in bonding It occurs due to poor or ineffective shielding of the ns2 ndash electrons of the valance shell by intervening d and f ndash electrons It increases down the group and thus the lower elements of the group exhibit lower oxidation states
OXIDATION STATES B and Al show oxidation states of +3 only
while Ga In and Tl exhibit oxidation states of both +1 and +3
As we move down in the group 13 due to inert pair effect the tendency to exhibit +3 oxidation states decreases and the tendency to attain +1 oxidation states increases
Stability of +1 oxidation state follows the order GaltInltTl
FB F
F+ NH3
FB
FF
NH3
LEWIS ACIDS Boron trifluoride is trivalent molecule of boron
The number of electrons around central boron atom in this molecule is only six It has incomplete octet Therefore this is electron deficient molecule and has tendency to accept lone pair of electrons to achieve stable inert gas electronic configuration Thus it behaves as Lewis acid
Stability in AlCl3 is formed due to the formation of dimer
Dimer It is a molecule or molecular complex consisting of two identical molecules linked together
Al AlCl
Cl
Cl
Cl
Cl
Cl
206pm221pm
101 7
9118
115 CHEMICAL REACTIVITY Action of Air (oxygen) Amorphous Boron
on heating in air forms B2O3 boron oxide eg 4B + 3O2 1000K 2B2O3
Boron trioxide Reactivity towards Halogens Boron reacts
with halogen to form Trihalides eg 2B+ 3Cl2 2BCl3 Boron trichloride
Reactivity towards Water Pure boron does not react with water Aluminum decomposes boiling water evolving hydrogen
eg 2Al + 6 H2O 2Al(OH)3 + 3H2
Gallium and Indium are not attacked
by pure cold or hot water Thallium is a little more reactive than Gallium and forms an oxide on the surface
116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON) Boron is a nonmetal while other members
are metals Boron shows allotropy while other
members do not Amongst the elements of group 13 boron
has highest MP and BP Boron forms only covalent
compounds(maximum covalence of boron is 3) while other members form both ionic and covalent compounds
Oxides and hydroxides of boron are weakly acidic of aluminium are amphoteric while those of rest of members are most basic
Boron hydride is quite stable while hydrides of other elements are less stable
Only boron combines with active metals such as Mg to form borides while rest of the members do not
3Mg + 2B Mg3B2
Magnesium BorideCrystalline boron is unreactive
973K
Boron with alkaliBoron dissolves with alkali to give
borates with evolution of H2 gas2B + 6NaOH 2Na3BO3+3H2
Reaction with acids-2B + 3HNO3 H3BO3+3NO2
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
ALUMINUM 13
GALLIUM31
IONIZATION ENTHALPY (IE or H) Ionization enthalpy also shows irregular
trends On moving down the group IE decreases from B to Al but the next element Ga has slightly higher ionization enthalpy than Al due to the poor shielding of intervening d-electrons It again decreases in and then increases in the last element
ELECTRONEGATIVITY Down the group the
electronegativity decreases from B to Al and then increases marginally This is due to the noticeable difference in atomic size of elements
ELEMENT ATOMIC RADIUSpm ELECTRONEGATIVITY
B 88 20Al 143 15
Ga 135 16In 167 17Tl 170 18
INERT PAIR EFFECT The phenomenon of electrons remaining
paired in valance shell is called inert pair effect
It is the reluctance of the s-electron of the valance shell to take part in bonding It occurs due to poor or ineffective shielding of the ns2 ndash electrons of the valance shell by intervening d and f ndash electrons It increases down the group and thus the lower elements of the group exhibit lower oxidation states
OXIDATION STATES B and Al show oxidation states of +3 only
while Ga In and Tl exhibit oxidation states of both +1 and +3
As we move down in the group 13 due to inert pair effect the tendency to exhibit +3 oxidation states decreases and the tendency to attain +1 oxidation states increases
Stability of +1 oxidation state follows the order GaltInltTl
FB F
F+ NH3
FB
FF
NH3
LEWIS ACIDS Boron trifluoride is trivalent molecule of boron
The number of electrons around central boron atom in this molecule is only six It has incomplete octet Therefore this is electron deficient molecule and has tendency to accept lone pair of electrons to achieve stable inert gas electronic configuration Thus it behaves as Lewis acid
Stability in AlCl3 is formed due to the formation of dimer
Dimer It is a molecule or molecular complex consisting of two identical molecules linked together
Al AlCl
Cl
Cl
Cl
Cl
Cl
206pm221pm
101 7
9118
115 CHEMICAL REACTIVITY Action of Air (oxygen) Amorphous Boron
on heating in air forms B2O3 boron oxide eg 4B + 3O2 1000K 2B2O3
Boron trioxide Reactivity towards Halogens Boron reacts
with halogen to form Trihalides eg 2B+ 3Cl2 2BCl3 Boron trichloride
Reactivity towards Water Pure boron does not react with water Aluminum decomposes boiling water evolving hydrogen
eg 2Al + 6 H2O 2Al(OH)3 + 3H2
Gallium and Indium are not attacked
by pure cold or hot water Thallium is a little more reactive than Gallium and forms an oxide on the surface
116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON) Boron is a nonmetal while other members
are metals Boron shows allotropy while other
members do not Amongst the elements of group 13 boron
has highest MP and BP Boron forms only covalent
compounds(maximum covalence of boron is 3) while other members form both ionic and covalent compounds
Oxides and hydroxides of boron are weakly acidic of aluminium are amphoteric while those of rest of members are most basic
Boron hydride is quite stable while hydrides of other elements are less stable
Only boron combines with active metals such as Mg to form borides while rest of the members do not
3Mg + 2B Mg3B2
Magnesium BorideCrystalline boron is unreactive
973K
Boron with alkaliBoron dissolves with alkali to give
borates with evolution of H2 gas2B + 6NaOH 2Na3BO3+3H2
Reaction with acids-2B + 3HNO3 H3BO3+3NO2
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
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FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
IONIZATION ENTHALPY (IE or H) Ionization enthalpy also shows irregular
trends On moving down the group IE decreases from B to Al but the next element Ga has slightly higher ionization enthalpy than Al due to the poor shielding of intervening d-electrons It again decreases in and then increases in the last element
ELECTRONEGATIVITY Down the group the
electronegativity decreases from B to Al and then increases marginally This is due to the noticeable difference in atomic size of elements
ELEMENT ATOMIC RADIUSpm ELECTRONEGATIVITY
B 88 20Al 143 15
Ga 135 16In 167 17Tl 170 18
INERT PAIR EFFECT The phenomenon of electrons remaining
paired in valance shell is called inert pair effect
It is the reluctance of the s-electron of the valance shell to take part in bonding It occurs due to poor or ineffective shielding of the ns2 ndash electrons of the valance shell by intervening d and f ndash electrons It increases down the group and thus the lower elements of the group exhibit lower oxidation states
OXIDATION STATES B and Al show oxidation states of +3 only
while Ga In and Tl exhibit oxidation states of both +1 and +3
As we move down in the group 13 due to inert pair effect the tendency to exhibit +3 oxidation states decreases and the tendency to attain +1 oxidation states increases
Stability of +1 oxidation state follows the order GaltInltTl
FB F
F+ NH3
FB
FF
NH3
LEWIS ACIDS Boron trifluoride is trivalent molecule of boron
The number of electrons around central boron atom in this molecule is only six It has incomplete octet Therefore this is electron deficient molecule and has tendency to accept lone pair of electrons to achieve stable inert gas electronic configuration Thus it behaves as Lewis acid
Stability in AlCl3 is formed due to the formation of dimer
Dimer It is a molecule or molecular complex consisting of two identical molecules linked together
Al AlCl
Cl
Cl
Cl
Cl
Cl
206pm221pm
101 7
9118
115 CHEMICAL REACTIVITY Action of Air (oxygen) Amorphous Boron
on heating in air forms B2O3 boron oxide eg 4B + 3O2 1000K 2B2O3
Boron trioxide Reactivity towards Halogens Boron reacts
with halogen to form Trihalides eg 2B+ 3Cl2 2BCl3 Boron trichloride
Reactivity towards Water Pure boron does not react with water Aluminum decomposes boiling water evolving hydrogen
eg 2Al + 6 H2O 2Al(OH)3 + 3H2
Gallium and Indium are not attacked
by pure cold or hot water Thallium is a little more reactive than Gallium and forms an oxide on the surface
116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON) Boron is a nonmetal while other members
are metals Boron shows allotropy while other
members do not Amongst the elements of group 13 boron
has highest MP and BP Boron forms only covalent
compounds(maximum covalence of boron is 3) while other members form both ionic and covalent compounds
Oxides and hydroxides of boron are weakly acidic of aluminium are amphoteric while those of rest of members are most basic
Boron hydride is quite stable while hydrides of other elements are less stable
Only boron combines with active metals such as Mg to form borides while rest of the members do not
3Mg + 2B Mg3B2
Magnesium BorideCrystalline boron is unreactive
973K
Boron with alkaliBoron dissolves with alkali to give
borates with evolution of H2 gas2B + 6NaOH 2Na3BO3+3H2
Reaction with acids-2B + 3HNO3 H3BO3+3NO2
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
ELECTRONEGATIVITY Down the group the
electronegativity decreases from B to Al and then increases marginally This is due to the noticeable difference in atomic size of elements
ELEMENT ATOMIC RADIUSpm ELECTRONEGATIVITY
B 88 20Al 143 15
Ga 135 16In 167 17Tl 170 18
INERT PAIR EFFECT The phenomenon of electrons remaining
paired in valance shell is called inert pair effect
It is the reluctance of the s-electron of the valance shell to take part in bonding It occurs due to poor or ineffective shielding of the ns2 ndash electrons of the valance shell by intervening d and f ndash electrons It increases down the group and thus the lower elements of the group exhibit lower oxidation states
OXIDATION STATES B and Al show oxidation states of +3 only
while Ga In and Tl exhibit oxidation states of both +1 and +3
As we move down in the group 13 due to inert pair effect the tendency to exhibit +3 oxidation states decreases and the tendency to attain +1 oxidation states increases
Stability of +1 oxidation state follows the order GaltInltTl
FB F
F+ NH3
FB
FF
NH3
LEWIS ACIDS Boron trifluoride is trivalent molecule of boron
The number of electrons around central boron atom in this molecule is only six It has incomplete octet Therefore this is electron deficient molecule and has tendency to accept lone pair of electrons to achieve stable inert gas electronic configuration Thus it behaves as Lewis acid
Stability in AlCl3 is formed due to the formation of dimer
Dimer It is a molecule or molecular complex consisting of two identical molecules linked together
Al AlCl
Cl
Cl
Cl
Cl
Cl
206pm221pm
101 7
9118
115 CHEMICAL REACTIVITY Action of Air (oxygen) Amorphous Boron
on heating in air forms B2O3 boron oxide eg 4B + 3O2 1000K 2B2O3
Boron trioxide Reactivity towards Halogens Boron reacts
with halogen to form Trihalides eg 2B+ 3Cl2 2BCl3 Boron trichloride
Reactivity towards Water Pure boron does not react with water Aluminum decomposes boiling water evolving hydrogen
eg 2Al + 6 H2O 2Al(OH)3 + 3H2
Gallium and Indium are not attacked
by pure cold or hot water Thallium is a little more reactive than Gallium and forms an oxide on the surface
116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON) Boron is a nonmetal while other members
are metals Boron shows allotropy while other
members do not Amongst the elements of group 13 boron
has highest MP and BP Boron forms only covalent
compounds(maximum covalence of boron is 3) while other members form both ionic and covalent compounds
Oxides and hydroxides of boron are weakly acidic of aluminium are amphoteric while those of rest of members are most basic
Boron hydride is quite stable while hydrides of other elements are less stable
Only boron combines with active metals such as Mg to form borides while rest of the members do not
3Mg + 2B Mg3B2
Magnesium BorideCrystalline boron is unreactive
973K
Boron with alkaliBoron dissolves with alkali to give
borates with evolution of H2 gas2B + 6NaOH 2Na3BO3+3H2
Reaction with acids-2B + 3HNO3 H3BO3+3NO2
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
INERT PAIR EFFECT The phenomenon of electrons remaining
paired in valance shell is called inert pair effect
It is the reluctance of the s-electron of the valance shell to take part in bonding It occurs due to poor or ineffective shielding of the ns2 ndash electrons of the valance shell by intervening d and f ndash electrons It increases down the group and thus the lower elements of the group exhibit lower oxidation states
OXIDATION STATES B and Al show oxidation states of +3 only
while Ga In and Tl exhibit oxidation states of both +1 and +3
As we move down in the group 13 due to inert pair effect the tendency to exhibit +3 oxidation states decreases and the tendency to attain +1 oxidation states increases
Stability of +1 oxidation state follows the order GaltInltTl
FB F
F+ NH3
FB
FF
NH3
LEWIS ACIDS Boron trifluoride is trivalent molecule of boron
The number of electrons around central boron atom in this molecule is only six It has incomplete octet Therefore this is electron deficient molecule and has tendency to accept lone pair of electrons to achieve stable inert gas electronic configuration Thus it behaves as Lewis acid
Stability in AlCl3 is formed due to the formation of dimer
Dimer It is a molecule or molecular complex consisting of two identical molecules linked together
Al AlCl
Cl
Cl
Cl
Cl
Cl
206pm221pm
101 7
9118
115 CHEMICAL REACTIVITY Action of Air (oxygen) Amorphous Boron
on heating in air forms B2O3 boron oxide eg 4B + 3O2 1000K 2B2O3
Boron trioxide Reactivity towards Halogens Boron reacts
with halogen to form Trihalides eg 2B+ 3Cl2 2BCl3 Boron trichloride
Reactivity towards Water Pure boron does not react with water Aluminum decomposes boiling water evolving hydrogen
eg 2Al + 6 H2O 2Al(OH)3 + 3H2
Gallium and Indium are not attacked
by pure cold or hot water Thallium is a little more reactive than Gallium and forms an oxide on the surface
116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON) Boron is a nonmetal while other members
are metals Boron shows allotropy while other
members do not Amongst the elements of group 13 boron
has highest MP and BP Boron forms only covalent
compounds(maximum covalence of boron is 3) while other members form both ionic and covalent compounds
Oxides and hydroxides of boron are weakly acidic of aluminium are amphoteric while those of rest of members are most basic
Boron hydride is quite stable while hydrides of other elements are less stable
Only boron combines with active metals such as Mg to form borides while rest of the members do not
3Mg + 2B Mg3B2
Magnesium BorideCrystalline boron is unreactive
973K
Boron with alkaliBoron dissolves with alkali to give
borates with evolution of H2 gas2B + 6NaOH 2Na3BO3+3H2
Reaction with acids-2B + 3HNO3 H3BO3+3NO2
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
OXIDATION STATES B and Al show oxidation states of +3 only
while Ga In and Tl exhibit oxidation states of both +1 and +3
As we move down in the group 13 due to inert pair effect the tendency to exhibit +3 oxidation states decreases and the tendency to attain +1 oxidation states increases
Stability of +1 oxidation state follows the order GaltInltTl
FB F
F+ NH3
FB
FF
NH3
LEWIS ACIDS Boron trifluoride is trivalent molecule of boron
The number of electrons around central boron atom in this molecule is only six It has incomplete octet Therefore this is electron deficient molecule and has tendency to accept lone pair of electrons to achieve stable inert gas electronic configuration Thus it behaves as Lewis acid
Stability in AlCl3 is formed due to the formation of dimer
Dimer It is a molecule or molecular complex consisting of two identical molecules linked together
Al AlCl
Cl
Cl
Cl
Cl
Cl
206pm221pm
101 7
9118
115 CHEMICAL REACTIVITY Action of Air (oxygen) Amorphous Boron
on heating in air forms B2O3 boron oxide eg 4B + 3O2 1000K 2B2O3
Boron trioxide Reactivity towards Halogens Boron reacts
with halogen to form Trihalides eg 2B+ 3Cl2 2BCl3 Boron trichloride
Reactivity towards Water Pure boron does not react with water Aluminum decomposes boiling water evolving hydrogen
eg 2Al + 6 H2O 2Al(OH)3 + 3H2
Gallium and Indium are not attacked
by pure cold or hot water Thallium is a little more reactive than Gallium and forms an oxide on the surface
116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON) Boron is a nonmetal while other members
are metals Boron shows allotropy while other
members do not Amongst the elements of group 13 boron
has highest MP and BP Boron forms only covalent
compounds(maximum covalence of boron is 3) while other members form both ionic and covalent compounds
Oxides and hydroxides of boron are weakly acidic of aluminium are amphoteric while those of rest of members are most basic
Boron hydride is quite stable while hydrides of other elements are less stable
Only boron combines with active metals such as Mg to form borides while rest of the members do not
3Mg + 2B Mg3B2
Magnesium BorideCrystalline boron is unreactive
973K
Boron with alkaliBoron dissolves with alkali to give
borates with evolution of H2 gas2B + 6NaOH 2Na3BO3+3H2
Reaction with acids-2B + 3HNO3 H3BO3+3NO2
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
FB F
F+ NH3
FB
FF
NH3
LEWIS ACIDS Boron trifluoride is trivalent molecule of boron
The number of electrons around central boron atom in this molecule is only six It has incomplete octet Therefore this is electron deficient molecule and has tendency to accept lone pair of electrons to achieve stable inert gas electronic configuration Thus it behaves as Lewis acid
Stability in AlCl3 is formed due to the formation of dimer
Dimer It is a molecule or molecular complex consisting of two identical molecules linked together
Al AlCl
Cl
Cl
Cl
Cl
Cl
206pm221pm
101 7
9118
115 CHEMICAL REACTIVITY Action of Air (oxygen) Amorphous Boron
on heating in air forms B2O3 boron oxide eg 4B + 3O2 1000K 2B2O3
Boron trioxide Reactivity towards Halogens Boron reacts
with halogen to form Trihalides eg 2B+ 3Cl2 2BCl3 Boron trichloride
Reactivity towards Water Pure boron does not react with water Aluminum decomposes boiling water evolving hydrogen
eg 2Al + 6 H2O 2Al(OH)3 + 3H2
Gallium and Indium are not attacked
by pure cold or hot water Thallium is a little more reactive than Gallium and forms an oxide on the surface
116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON) Boron is a nonmetal while other members
are metals Boron shows allotropy while other
members do not Amongst the elements of group 13 boron
has highest MP and BP Boron forms only covalent
compounds(maximum covalence of boron is 3) while other members form both ionic and covalent compounds
Oxides and hydroxides of boron are weakly acidic of aluminium are amphoteric while those of rest of members are most basic
Boron hydride is quite stable while hydrides of other elements are less stable
Only boron combines with active metals such as Mg to form borides while rest of the members do not
3Mg + 2B Mg3B2
Magnesium BorideCrystalline boron is unreactive
973K
Boron with alkaliBoron dissolves with alkali to give
borates with evolution of H2 gas2B + 6NaOH 2Na3BO3+3H2
Reaction with acids-2B + 3HNO3 H3BO3+3NO2
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Stability in AlCl3 is formed due to the formation of dimer
Dimer It is a molecule or molecular complex consisting of two identical molecules linked together
Al AlCl
Cl
Cl
Cl
Cl
Cl
206pm221pm
101 7
9118
115 CHEMICAL REACTIVITY Action of Air (oxygen) Amorphous Boron
on heating in air forms B2O3 boron oxide eg 4B + 3O2 1000K 2B2O3
Boron trioxide Reactivity towards Halogens Boron reacts
with halogen to form Trihalides eg 2B+ 3Cl2 2BCl3 Boron trichloride
Reactivity towards Water Pure boron does not react with water Aluminum decomposes boiling water evolving hydrogen
eg 2Al + 6 H2O 2Al(OH)3 + 3H2
Gallium and Indium are not attacked
by pure cold or hot water Thallium is a little more reactive than Gallium and forms an oxide on the surface
116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON) Boron is a nonmetal while other members
are metals Boron shows allotropy while other
members do not Amongst the elements of group 13 boron
has highest MP and BP Boron forms only covalent
compounds(maximum covalence of boron is 3) while other members form both ionic and covalent compounds
Oxides and hydroxides of boron are weakly acidic of aluminium are amphoteric while those of rest of members are most basic
Boron hydride is quite stable while hydrides of other elements are less stable
Only boron combines with active metals such as Mg to form borides while rest of the members do not
3Mg + 2B Mg3B2
Magnesium BorideCrystalline boron is unreactive
973K
Boron with alkaliBoron dissolves with alkali to give
borates with evolution of H2 gas2B + 6NaOH 2Na3BO3+3H2
Reaction with acids-2B + 3HNO3 H3BO3+3NO2
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
115 CHEMICAL REACTIVITY Action of Air (oxygen) Amorphous Boron
on heating in air forms B2O3 boron oxide eg 4B + 3O2 1000K 2B2O3
Boron trioxide Reactivity towards Halogens Boron reacts
with halogen to form Trihalides eg 2B+ 3Cl2 2BCl3 Boron trichloride
Reactivity towards Water Pure boron does not react with water Aluminum decomposes boiling water evolving hydrogen
eg 2Al + 6 H2O 2Al(OH)3 + 3H2
Gallium and Indium are not attacked
by pure cold or hot water Thallium is a little more reactive than Gallium and forms an oxide on the surface
116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON) Boron is a nonmetal while other members
are metals Boron shows allotropy while other
members do not Amongst the elements of group 13 boron
has highest MP and BP Boron forms only covalent
compounds(maximum covalence of boron is 3) while other members form both ionic and covalent compounds
Oxides and hydroxides of boron are weakly acidic of aluminium are amphoteric while those of rest of members are most basic
Boron hydride is quite stable while hydrides of other elements are less stable
Only boron combines with active metals such as Mg to form borides while rest of the members do not
3Mg + 2B Mg3B2
Magnesium BorideCrystalline boron is unreactive
973K
Boron with alkaliBoron dissolves with alkali to give
borates with evolution of H2 gas2B + 6NaOH 2Na3BO3+3H2
Reaction with acids-2B + 3HNO3 H3BO3+3NO2
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Reactivity towards Water Pure boron does not react with water Aluminum decomposes boiling water evolving hydrogen
eg 2Al + 6 H2O 2Al(OH)3 + 3H2
Gallium and Indium are not attacked
by pure cold or hot water Thallium is a little more reactive than Gallium and forms an oxide on the surface
116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON) Boron is a nonmetal while other members
are metals Boron shows allotropy while other
members do not Amongst the elements of group 13 boron
has highest MP and BP Boron forms only covalent
compounds(maximum covalence of boron is 3) while other members form both ionic and covalent compounds
Oxides and hydroxides of boron are weakly acidic of aluminium are amphoteric while those of rest of members are most basic
Boron hydride is quite stable while hydrides of other elements are less stable
Only boron combines with active metals such as Mg to form borides while rest of the members do not
3Mg + 2B Mg3B2
Magnesium BorideCrystalline boron is unreactive
973K
Boron with alkaliBoron dissolves with alkali to give
borates with evolution of H2 gas2B + 6NaOH 2Na3BO3+3H2
Reaction with acids-2B + 3HNO3 H3BO3+3NO2
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON) Boron is a nonmetal while other members
are metals Boron shows allotropy while other
members do not Amongst the elements of group 13 boron
has highest MP and BP Boron forms only covalent
compounds(maximum covalence of boron is 3) while other members form both ionic and covalent compounds
Oxides and hydroxides of boron are weakly acidic of aluminium are amphoteric while those of rest of members are most basic
Boron hydride is quite stable while hydrides of other elements are less stable
Only boron combines with active metals such as Mg to form borides while rest of the members do not
3Mg + 2B Mg3B2
Magnesium BorideCrystalline boron is unreactive
973K
Boron with alkaliBoron dissolves with alkali to give
borates with evolution of H2 gas2B + 6NaOH 2Na3BO3+3H2
Reaction with acids-2B + 3HNO3 H3BO3+3NO2
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Oxides and hydroxides of boron are weakly acidic of aluminium are amphoteric while those of rest of members are most basic
Boron hydride is quite stable while hydrides of other elements are less stable
Only boron combines with active metals such as Mg to form borides while rest of the members do not
3Mg + 2B Mg3B2
Magnesium BorideCrystalline boron is unreactive
973K
Boron with alkaliBoron dissolves with alkali to give
borates with evolution of H2 gas2B + 6NaOH 2Na3BO3+3H2
Reaction with acids-2B + 3HNO3 H3BO3+3NO2
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
973K
Boron with alkaliBoron dissolves with alkali to give
borates with evolution of H2 gas2B + 6NaOH 2Na3BO3+3H2
Reaction with acids-2B + 3HNO3 H3BO3+3NO2
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Boron ndash glasses ceramics and agricultureAluminum ndash electrical devices and
construction materialsGallium ndash amplifiers solar cells and
satellitesIndium ndash coatings and alloysThallium ndash photo electric cell and toxics
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Boron Electronic structure ndash 1s2 2s2 2p1 Atomic
radius ndash 90 pm Due to this relatively small size of boron
the sum of its first three ionization enthalpies is very high
This prevents it to form 3+ ions and forces it to form only covalent compounds
In the trivalent state boron can be called as electron deficient as it will have only 6 electrons in its outer most orbit Thus Boron has a tendency to accept a lone pair of electrons from another compound to become stable
This property also makes the compound a Lewis acid
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
IT IS UNREACTIVE IN CRYSTALLINE FORM HOWEVER AMORPHOUS BORON ON
HEATING IN AIR FORMS IT REACTS WITH DINITROGEN AT HIGH TEMPERATURES TO FORM NITRIDES
B2O3 IS ACIDIC AND REACTS WITH BASIC OXIDES FORMING METAL BORATES
IT DOES NOT REACT WITH ACIDS AND ALKANES
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Aluminum and other group 13 elements
Sum of the first three ionization enthalpies is less as compared to Boron this is due to the easy tendency to lose electrons It is able to form Al 3+
In the other elements due to poor shielding effect of d and f orbitals the nucleus holds the outer most s electrons tightly Thus only p bonding may be available for bonding
In all 3 elements both +1 and +3 oxidation states are seen
The compounds in +1 state are more ionic than
those in +3 state
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Aluminum forms a very thin oxide layer With di nitrogen at high temperatures they form nitrides
It dissolves in mineral acids and aqueous alkalies and thus show amphoteric character
All the group 13 elements except thallium show reactivity towards halogens
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
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FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
2E(s) + 3O2(g) 2E2O3(s) 2E (s) + N2(g) 2EN(s) [ E = element ] 2Al(s) + 6HCl (aq) 2Al3+(aq) + 6Cl-
(aq) + 3H2(g)
2E(s) + 3X2(g) 2EX3 (s)
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
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| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
BORON AND ITS COMPOUNDS
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
BoraxIt is the most important compound of boron It is a white crystalline solid of formula Na2B4O7sdot10H2O Borax dissolves in water to give an alkaline solution Na2B4O7 + 7H2O 2NaOH + 4H3BO3 Orthoboric acid
On heating borax first loses water molecules and swells up On further heating it turns into a transparent liquid which solidifies into glass like material known as borax beadNa2B4O710H2O Na2B4O7 2NaBO2+ B2O3 sodium metaborate
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Orthoboric acidHusna 118 ii to 118 iii
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
ORTHOBORIC ACID(H
3BO3)
It is a white crystalline solid with a soapy touch
It is sparingly soluble in water but highly soluble in hot water
Obtained from borax by treating with dil HCL or dilH2SO4
Na2B4O7+ 2HCl+5H2O 2NaCl +4H3BO3
Also obtained from mineral colemanite by passing so2 through a mixture of powerdered mineral in boiling water
Ca2B6O11+4SO2+11H2O 2Ca(HSO3)2+ 6H3BO3
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Uses of orthoboric acid
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
As mild antiseptic for eyewash Also named as boric lotion
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
As food preservative
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Preparation of enamels and glazes on pottery
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
III Diborane
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
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FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Diborane B2H6 It is simplest boron hydride
Prepared by treating boron trifluride with LiA1H4 in dielene ethylene
4BF3 + 3LiAlH4 + 2B2H6 + 3LiF + 3AlF3
IN laboratory the Diborane is prepared by the oxidation of sodium borohydride with iodine
2NaBH4 + I2 B2H6 + 2NaI + H2
In industry prepared by reaction of BF3 with sodium hydride
2BF3 + 6 NaH B2H6 + 6NaF 450k
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
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FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Diborane
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
PROPERTIES Colourless highly toxic gas Boiling point of 180 K Catches fire spontaneously
when exposed to atmospheric airit Burns in oxygen The reaction is exothermic releasing a large amount of energy
B2H6 + 3O2 B2O3 +3H2O ∆H= -1976 kJ mol-1
Readily hydrolyzed by water to form boric acid
B2H6 (g) + 6H2O(l) 2B (OH)3 (aq) + 6H2(g)
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
With Lewis bases it first undergoes cleavage to form borane (BH 3) which then reacts to form adducts
B 2H 6 + 2NMe 3 2BH 3 NMe 3
B 2H 6 + 2CO 2BH 3 CO
With ammonium an addition product B 2H 6 2NH 3 formulated as eq is formed which then decomposes on heating at 473K to give a volati le compound cal led borazole
3B 2H 6 + 6NH 3 3 [BH 2 (NH 3)2]+ [BH 4] -
B o r a z o l e ( B o r e z i n e )
2B 3N 3H 6 + 12H 2
473k
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
SP3 ATOMS UNDERGO HYTBRIDAZATIONTHERE ARER FOUR TERMINAL B-HT NORMAL COVALENT BONDS WHICH ARE
QUITE STRONG (ALSO CALLED TWO CENTRAL ELECTRONE PAIRE BOND OR TWO CENTRE TWO ELECTRONE BONDS IE 2C-2E) AND TWO BRIDGE BhellipHB hellipB WHICH ARE DIFFERENT FROM NORMAL COVALENT BONDS AND ARE QUITE WEAK (ALSO CALLED three centre electron pair bond or three resemblance to a banana these are also called banana bond
STRUCTRE OF B2H6
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
It is also called as inorganic benzene in view of its ring structure with alternate NH and BH groups
Borozole contains three double bonds and 6pie electron system which is similar to benzene
Many metals hybrids react with dilborane to form tetrehydridoborate which contains BH4 tetradral ion
2MH + B2H6 2M+ [BH4]-
(where M + Li or Na)
diethylether
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
STRUCTURE OF BORON
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
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| | | |
| | | |
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FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Uses of boron
Boron being extreamly hard refractory solid of high melting pointlow density and low electrtical Conductivity finds many applications The main industrial application of borax and boric acid is in the manufacure of heat resistant glasses (eg Pyrex )glass wool and fibre glassborax is used in flux for soldering of metalsfor heatscratch and stain resistant glazed coating to earthenwares and as consituent of medicinal soapsan aqueous solution of orthoboric acid is generally used as a mild antiseptic
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
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| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
Aluminium is a bright silvery white metal with high tensil strengthit has high eletrical and thermal conduccytivity Aluminium forms alloy with CuMgMnFeNiCo
Aluminium is a chief constitiunt of silvery paints Alums are used in purification of water It also used in sizing of papersit acts as septic to stop bledingit is quite used in deying and tanning of leatheralums have good application in dehydrationdecolouraton and chromatography
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Reaction with acids and alkalies
Reaction with acid Aluminium dissolves in dil or
conHcl and dilH2so4 SLOWLY LIBERATING H2 GAS WHILE CONCH2SO4 GIVES SO2 GAS
2Al+ 6HCL(dil) + 12H2O 2[Al(H2o)]cl3 3H2
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
REACTION WITH ALKALIES ALUMINIUM DISSOLVES IN NAOH OR
KOH TO FORM META-ALUMINATE WITH THE EVOLUTION OF H2 GAS
2Al + 2naoh+ 2H2o 2NaAlo2+ 3H2
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
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| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Group 14 Elements
Anam 1111 to 11116
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
General introduction and occurrence
Carbon(C) silicon(Si) germanium(Ge) tin(Sn) and lead(Pb)are the elements of group 14
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
C and silicon are non metals Ge is a metalloid whereas Pb and Sn are metal
Carbon is seventeenth most
abundant element by weight in the earth crust and forms many compounds than any other elements except hydrogen
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Carbon has two stable isotopes 12C(989) and 13C(11) It is widely distributed in nature in free state as
well as in the combined form Carbon has third isotope as 14C It is radioactive and used for radiocarbon dating
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
In elemental form it is available in coal graphite diamond
Coal diamond graphite
In combined form it is available as metal carbonates hydrocarbons and carbon dioxide gas (003) in air Carbon is versatile element in the world
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Fats carbohydrates proteins vitamins etc and fossil fuels such as petroleum lignite are made up of carbon compounds carbon is essential constituent of all living organisms
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Silicon is the second (277 by mass) most abundant element in the earth crust It is present in nature as silica(SiO2) and silicates It is a very important component of ceramics glass and cement
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Germanium exists only in traces Tin occurs as SnO2 (cassiterite or tinstone) and lead as galena(PbS)
Ultrs pure germanium and silicon are used in making transistors and semiconductor devices
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Electronic Configuration
The valence shell electronic configuration of these element is ns2np2
The inner core of the electronic configuration of element in this group differs
Hence C and Si has inert gas core Ge and Sn have inert gas core plus 10d-electronput Pb has inert gas core plus 10d-electron and 14f-electron
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
ELEMENTSYMB
OL ATOMICNO
ELECTRONIC CONFIGURATIO
N
Carbon C 6 [He] 2s2 2p2
Silicon Si 14 [Ne] 3s2 3p2
Germanium Ge 32[Ar] 3d10 4s2
4p2
Tin Sn 50[Kr] 4d10 5s2
5p2
Lead Pb 82[Xe] 5d10 6s2
6p2
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Variation of properties Here we are considering atomic radii
ionization enthalpy electronegativity and physical properties Electronic configuration of group 14 is shown in table117
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Atomic Radii (covalent radii)
Atomic radii of these elements regularly increase as we move down the group primarily due to addition of new every shell at each succeeding element The increase in atomic radii from Si
onwards is however small due to ineffective shielding of the valence electrons by the intervening d- and f- electron
Heavier elements have completely filled d and f orbitals
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Ionization enthalpy The ionization enthalpy of group 14
element is higher than the corresponding elements of group 13 due to increased nuclear charge
The influence of inner core electrons is visible In general the ionization enthalpy decreases down the group
Small decrease in ∆H1 from Si to Ge to Sn and slight increase in ∆H1 from Sn to Pb is consequence of poor shielding effect pf intervening d and f orbitals and increase in size of atom
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Electronegativity Due to small size the
element of this group are slightly more electronegative than the corresponding group 13 element
The electronegativity decreases as we move down the group but not after silicon
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
The electro negativity values for elements from Si to Pb are almost the same Carbon with electronegativity of 25 is the most electronegative element of group 14
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Oxidation states The group 14 elements have four electrons in
the outer most shell All the elements show an oxidation state of +4
However as we move down the group from C to Pb the stability of +4 oxidation state decreases while that of +2 oxidation state increases due to inert pair effect
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
bull Carbon also exhibits negative oxidation states Since the sum of first four ionization
enthalpies is very high compounds in +4 oxidation states are generally covalent in nature
bull In heavier elements the tendency to show +2 oxidation state increases in order GeltSnltPb
bull It is due to the inability of ns2 electron of valence shell to participate in bonding
bull Carbon and silicon mostly show +4 oxidation state
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Germanium forms stable compounds in +4 oxidation state and very few compounds in +2 state Tin forms divalent as well as tetravalent compounds Sn in +2 state is reducing agent Lead compounds are stable in +2 state Lead in +4 oxidation states acts as oxidizing agent (PbO2) Carbon show maximum covalence as four Other elements because of the presence of d orbitals show covalence more than 4
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Physical properties All the group 14 elements are solids
Carbon and silicon are non metals germanium is metalloid where as tin and lead are soft metals with low melting points
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
The mp and bp of group 14 elements are higher than those of corresponding elements of group 13 This is due to strong interacting binding forces in their solids as well as in liquid states Down the group there is regular decrease in mp and bp as the size of atoms
increases and interatomic forces of attraction decreases Hence silicon is hard while lead is a soft metal
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Trends in Chemical Reactivity
It can be studied through different mediums
i Reactivity towards Oxygen
ii Reactivity towards Water
iii Reactivity towards Halogen
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Reactivity towards Oxygen
The elements of group 14 form two types of oxides monoxides of the type MO and dioxides of the type MO2
All elements of group 14 except Si form monoxides
Among dioxides CO2 exist as linear monomeric molecules (O=C=O)
E + E
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Reactivity towards Water
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Reactivity towards Halogen
Elements of Group 14 form two types of halides Tetra halides (MX4) and Di halides (MX2)
The tetra halides are covalent in nature Their thermal stability decreases down the group The tetra halides of group 14 except that of carbon are readily hydrolyzed
SiCl4 + 4H2O Si(OH)4 + 4 HCl
In carbon there is no vacant d -orbitals Hence it can not increase its valency beyond four Therefore tetra halides of carbon are not hydrolyzed
The stability of dihalides of group 14 increases as we descend the group
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Anomalous Behaviour of Carbon Like first member of other groups carbon
also differs from the rest of the members of its group
It is due to its smaller size higher electronegativity higher ionization enthalpy and unavailability of d-orbitals
In carbon only s and p-orbitals are available for bonding and therefore it can accommodate only four pairs of electrons around it This would limit the maximum covalence to four whereas other members can expand their covalence due to the presence of d-orbitals
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
CATENATION Carbon atoms have a tendency to link with
another through covalent bonds to form chains and rings This property is called catenation This is because C ndash C bonds are very strong
Down the group the size increases and electronegativity decreases and thereby tendency to show catenation decreases This can be clearly seen from bond enthalpy values
The order of catenation is C gtgt Si gt Ge gtgt Sn
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
CATENATION Lead does not show catenation Bond Bond Enthalpy kJ mol-1 C ndash C 348 Si ndash Si 297 Ge ndash Ge 260 Sn ndash Sn 240
Carbon also has unique ability to form ndash multiple bonds with itself and with other atoms of smaller size and high electronegativity Few examples are C = C C ordm C C = O C = S and C ordm N Heavier elements do not form ndash bonds because their atomic orbitals are too large and diffuse to have effective overlapping
Due to property of catenation and ndash bond formation carbon is able to show allotropic forms
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
VIDEO
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Allotropes Allotropes are different physical forms of the same element
which have same chemical properties but different physical properties and the phenomenon is known as Allotropy
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
The Three Allotropes Of
CarbonCarbon can bond with itself in at least three different ways giving us 3 different materials
Diamond
Graphite
Buckminster-fullerenes
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Modifications of Allotropes
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
DIAMOND A diamond is something known as an allotrope
An extremely hard highly refractive crystalline formof carbon that is usually colourless and is used as
gemstone and in abrasives cutting tools and other applications
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Structure of Diamond Carbon has an electronic
arrangement of 24 In diamond each carbon shares electrons with four other carbon atoms - forming four single bonds
In the diagram some carbon atoms only seem to be forming two bonds (or even one bond) but thats not really the case We are only showing a small bit of the whole structure
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Properties of Diamond
High melting point due to strong directional covalent bonds (3550 C)
Extremely hard because it is difficult to break atoms apart or move them in relation to one another
No electrical conductivity because electrons are localized in specific bonds
Insoluble in polar and non-polar solvents because molecular bonds are stronger than any intermolecular forces
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
GRAPHITE
A soft crystalline allotrope of carbon composed of graphene layers having a steel-gray to Black
metallic luster and a greasy feel used in lead pencils
lubricants paints
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Structure of Graphite Each carbon atom is only covalently bonded to
three other carbon atoms rather than to four as in diamond
Graphite contains layers of carbon atoms Graphite has a layer structure which is quite
difficult to draw convincingly in three dimensions The diagram below shows the arrangement of the atoms in each layer and the way the layers are spaced
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Properties of Graphite Has a high melting point similar to that
of diamond Has a soft slippery feel and is used in
pencils and as a dry lubricant for things like locks
Has a lower density than diamond Conducts electricity The delocalised
electrons are free to move throughout the sheets
Is insoluble in water and organic solvents
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
FULLERENE A fullerene is a pure carbon molecule
composed of at least 60 atoms of carbon Because a fullerene takes a shape similar to a soccer ball or a geodesic dome it is sometimes referred to as a buckyball
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Structure of Fullerene They consist of hexagonal rings
of carbon atoms (like in graphite or graphene) and alternating pentagonal carbon rings to allow curvature of the surface
The carbon-carbon bonds in Buckminster Fullerene C60 form a pattern like a soccer ball and this fullerene is a brownish-reddish-magenta colour when dissolved in organic solvents
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Properties of Fullerene The molecule can act as a semiconductor
conductor and superconductor under specific conditions
Fullerenes can display the photochromic effect which is a change in light transmission based on intensity
Is essentially insoluble in polar solvents sparingly soluble in alkanes
Fullerenes are relatively safe and inert and yet have properties that allow the substance to create active derivatives
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
CARBON MONOXIDE
Direct combination of carbon in limited supply of air or oxygen gives carbon monoxide
2C(s)+O2 2CO(g)
C O
Carbon monoxide is both short-lived in atmosphere and spatially variable in concentrationChiefly it is a product of volcanic activity but also man-made fires burning of fossil fuels also contributes to carbon monoxide production
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
PROPERTIES OF CARBON MONOXIDE
Chemical formula- CO Appearance- Colorless Odor- Odorless Solubility- soluble in chloroform acetic acid
ethyl acetate ethanol ammonium hydroxide benzene
A powerful reducing agent and reduces almost all the metal oxides other than alkali and alkaline earth metals and few transitional elements
It is used in extraction of many metals from their oxides
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
EXTRACTION OF METALS
Fe2 O3 +3CO 2Fe(s) +3CO2(g)
CuO(s) + CO(g) Cu(s) + co2(g)
ZnO(s) + CO(g) Zn(s) + CO2(g)
Iron oxide + Iron + carbon dioxide
Carbon monoxide
Copper oxide +
Carbon monoxide
copper+ carbon dioxide
Zinc oxide +
Carbon monoxide
Zinc +
Carbon dioxide
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Hemoglobin carries oxygen and carbon dioxide
Hemoglobin
Red Blood Cell
Carbon monoxide binds very tightly to hemoglobin
O2 and Co2 can no longer be carried
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
CARBON DIOXIDE
1)It is prepared by complete combustion of carbon and carbon containing fuels in excess of air
C(S) + O2 ∆ CO2
CH4(g) + 2O2 ∆ CO2(g) + CO2(g)
+2H2O(g)2) It is prepared in the laboratory by the action of dilute HCl on calcium carbonate
CaCO3(s) + 2HCl(aq)∆ CaCl2(aq) + CO2(g) + H2O(l)
KHATIJA11172 TILL SILCON DI OXIDE
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
3)On commercial scale it is obtained by heating lime stone
CaCO31600K CaO + CO2
4) It is valuable byproduct in the manufacture of ethyl alcohol by fermentation of glucose and fructose
C6H12O6zymase 2C2H5OH + 2CO2
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
PROPERTIES It is a colourless and odourless gas Its low solubility in water makes it of great biochemical and geo chemical importance With water it forms carbonic acid which is a dibasic acid and disassociates in two stepsH2CO3(aq) + H2O(l) HCO⁻
3(aq) + H3O+(aq)
HCO⁻3(aq) + H2O(l) CO23⁻(aq) + H3O+
(aq)
H2CO3HCO3- buffer system helps to maintain pH
of blood between 726 to 742
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
6CO2+ 12H2O
chlorophyllsunlight
C6H12O6 +6H2O + 6O2
CO2 reacts with NH3 at 453 Kminus473K under a pressure of 220 atm to give urea as the final product
2NH3 + CO2453-473K220 atm
[NH2COONH4]rarrNH2COH2
Urea+H2OAmmonium carbonate
CO2 is acidic in nature it combines with alkanes to form metal carbonates
In photosynthesis CO2 is converted to glucose and O2
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
By photosynthesis plants make their own food for themselves as for animals and human beings In the recent years the increase of combustion of fossil fuels and decomposition of limestone for cement production seems to increase the CO2 content of the atmosphere This may lead to increase in green house effect
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
This enhanced green house effect raises the temperature of the atmosphere which might have serious consequences in the form of global warming and climate change
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Solid carbon dioxide is called dry ice since it does not wet the surface and gets directly converted to gaseous state Dry ice is used as coolant for preserving perishable articles in food industries and for making cold baths in laboratory Being heavy and non supporter of combustion it is used as fire extinguisher CO2 is a near molecule in which carbon atom is sp hybridized Two sp hybridized orbitals of carbon atom overlap with p-orbitals of oxygen atom to make two sigma bonds Other two electrons of carbon atom are involved in PprodminusPprod bonding with two oxygen atoms Both C-O bonds are of equal bond length of 115 pm In has no dipole movement Resonance structure of CO2 is shown below ⁻ O minusC Ξ O O =C=O OΞ CminusO ⁻
+ +
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
COMPOUNDS OF SILICONSilicon being second member of group 14 has a much larger size (118 pm) and lower electronegativity than that of carbon As a result silicon does not form double bond with silicon or oxygen Thus Si-O bond is much stronger than Si-Si and Si-H bonds Silicon has vacant 3d orbitals in its valence shell due to which it can extend its covalence from five ndashsix Important compounds of silicon are silicon dioxide silicon tetrachloride silicones silicates and ziolites
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
SILICON DIOXIDE SiO2Silicon dioxide is commonly known as silica
95 of the earths crust is made up of silica and silicates Silicon dioxide occurs quart
cristobalite and tridimite All these are crystalline forms of silica SiO2 is covalent in
nature It has three dimensional network solid in
which silicon atom is covalently bonded in a tetra hydral manner to four oxygen atoms
Each oxygen atom in turn is covalently bonded to another silicon atom It is shown in fig Each corner is shared with another tetrahedrons The entire crystal may be
regarded as giant molecule in which eight membered rings are formed with alternate
silicon and oxygen atoms
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
CRISTOBALITE TRIDIMITE
QUARTZ
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
O O O O
―Si―O―Si―O―Si―O―Si―
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
FIG 1111 STRUCTURE OF SiO2
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
SiO2 in its normal form is non reactive because of very high Si-O bond enthalpy It resists the attack by halogens dihydrogen and most of the acids and metals at elevated temperatures However it is attacked by HF and NaOH
SiO2 + 4HF rarr SiF4 + 2H2OSiO2 + 2NaOH rarr Na2SiO3 +H2O
Quarts ( a form of SiO2 ) is used as piezoelectric material Quarts can play
important role in making accurate clocks modern radio and television broad casting and mobile radio communications Silica gel is the
important compound if silica It is used as dehydrating agent and adsorbent in
chromatography Kieselguhr and amorphous form of silica is used in filtration plants
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
SILICON TETRACHLORIDE SiCl4
Silicon tetrachloride is the inorganic compound with the formula SiCl4 It is a colourless volatile liquid that fumes in air It is used to produce high purity silicon and silica for commercial applications
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
It is prepared by action of chlorine on siliconSi + 2Cl2 SiCl4
This tetrahalide is covalent in nature and possess tetrahedral geometryThe tetra chloride of carbon ieCCl4 is not hydrolysed by water but SiCl4 gets easily hydrolysed
CCl4 +H2O No reactionSiCl4 + 4H2O Si(OH)4 + 4HCl orthosilicic acid
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
EXPLANATION
Silicon and carbon both are the members of 14th group But Silicon tetrachloride reacts with water while carbon tetrachloride does not this is due to the fact that the carbon does not have d - orbitals to accept lone pair of electron from water while silicon has vacant d - orbitals to accept lone pair of electron from water
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
SILICONESSilicones are polymers that include any inert synthetic compound made up of repeating units of siloxane which is a chain of alternating silicon atoms and oxygen atoms frequently combined with carbon andor hydrogen They are typically heat-resistant and rubber-like and are used in sealants adhesives lubricants medicine cooking utensils and thermal and electrical insulation Some common forms include silicone oil silicone grease silicone rubber silicone resin and silicone caulk
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
FORMATION OF SILICONESEffective lubrication is provided by an interfacial monomolecular film of coadsorbed dimethylsilicone and fatty acid molecules This film continues to maintain low friction and wear with increasing temperature due to the reaction of the acid with the metal surfaces and the subsequent formation of the high-melting-point copper soap Electrical resistance measurements show this to be due to the formation of a thin non-conducting interfacial film which provides protection for the sliding surfaces up to temperatures in excess of 150degC
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
USES OF SILICONES
Soup ladle and pasta ladle are made up of silicones
A silicone food steamer to be placed inside a pot of boiling water
Ice cube trays made of silicone
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
SILICATESA silicate is a compound containing an anionic silicon compound The great majority of silicates are oxides but hexafluorosilicate ([SiF6]2minus) and other anions are also includedOrthosilicate is the anion SiO4
4minus or its compounds Related to orthosilicate are families of anions (and their compounds) with the formula [SiO2+n]2nminus Important members are the cyclic and single chain silicates [SiO3]2minusn and the sheet-forming silicates [SiO25]minusnSilicates comprise the majority of Earths crust as well as the other terrestrial planets rocky moons and asteroids
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
USES OF SILICATES
The main applications were in detergents paper water treatment and construction materials
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
STRUCTURE OF SILICON TETRACHLORIDE
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Silicates
Feldspar -NaAlSl3o8Mica- KH2Al3(Sio4) or KAl3Si3O(OH)Zeolite ndash Na2OAl2O3XSiO2YH2O
Structure of silicate-silicates are is sp3of SiO4 tetrahedral units silicon is Sp3 hybridized and surrounded by 4 oxygen atomsWhen all four corners are shared with other tetrahedral units a three dimensional network is formed and ndashve charge on silicate structure is neutralized by +vely charge metal ions
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
ZEOLITESZeolites are microporous aluminosilicate minerals commonly used as commercial adsorbents and catalystsThe term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt who observed that upon rapidly heating the material stilbite it produced large amounts of steam from water that had been adsorbed by the material Based on this he called the material zeolite from the Greek ζέω (zeacuteō) meaning to boil and λίθος (liacutethos) meaning stoneZeolites occur naturally but are also produced industrially on a large scale As of July 2015 229 unique zeolite frameworks have been identified and over 40 naturally occurring zeolite frameworks are known[
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
Zeolites are widely used as ion-exchange beds in domestic and commercial water purification softening and other applications In chemistry zeolites are used to separate molecules (only molecules of certain sizes and shapes can pass through) and as traps for molecules so they can be analyzed
USES OF ZEOLITES
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
- Slide 29
- Slide 30
- Slide 31
- Aluminum and other group 13 elements
- Slide 33
- Slide 34
- Slide 35
- Slide 36
- Slide 37
- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
- Slide 43
- Slide 44
- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
- Slide 64
- Slide 65
- Slide 66
- Slide 67
- Slide 68
- Slide 69
- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
- Slide 113
- Slide 114
- Slide 115
- Slide 116
- Slide 117
- Slide 118
- Slide 119
- Slide 120
- Slide 121
- Slide 122
- Slide 123
- Slide 124
- Slide 125
- Slide 126
- Slide 127
- Slide 128
- Slide 129
- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
-
- Slide 1
- Introduction
- Slide 3
- Positon of p block element
- P block elements
- General electronic configuration
- Slide 7
- Group 13 elements
- Electronic configuration
- Electronic configuration of 13 grp element
- Occurrence
- Slide 12
- 114 VARIATION IN PROPERTIES
- Slide 14
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- 115 CHEMICAL REACTIVITY
- Slide 22
- 116 ANOMALOUS PROPERTIES OF FIRST ELEMENT OF GROUP 13(BORON)
- Slide 24
- 973K
- Slide 26
- Boron
- Slide 28
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- Aluminum and other group 13 elements
- Slide 33
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- Orthoboric acid
- Orthoboric acid(H3BO3)
- Slide 40
- Uses of orthoboric acid
- Slide 42
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- Slide 45
- III Diborane
- Diborane B2H6
- Diborane
- PROPERTIES
- Slide 50
- STRUCTRE OF B2H6
- Slide 52
- Slide 53
- STRUCTURE OF BORON
- Slide 55
- Slide 56
- Uses of boron
- USES OF ALUMINIUM AND ALUMINIUM COMPPOUNNDS
- Reaction with acids and alkalies
- REACTION WITH ALKALIES
- Group 14 Elements
- General introduction and occurrence
- Slide 63
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- Electronic Configuration
- Slide 71
- Variation of properties
- Atomic Radii (covalent radii)
- Slide 74
- Ionization enthalpy
- Slide 76
- Electronegativity
- Slide 78
- Slide 79
- Oxidation states
- Slide 81
- Slide 82
- Physical properties
- Slide 84
- Slide 85
- Trends in Chemical Reactivity
- Reactivity towards Oxygen
- Reactivity towards Water
- Reactivity towards Halogen
- Anomalous Behaviour of Carbon
- Slide 91
- Slide 92
- VIDEO
- Allotropes
- The Three Allotropes Of Carbon
- Modifications of Allotropes
- DIAMOND
- Structure of Diamond
- Properties of Diamond
- GRAPHITE
- Structure of Graphite
- Properties of Graphite
- FULLERENE
- Structure of Fullerene
- Properties of Fullerene
- CARBON MONOXIDE
- Slide 107
- PROPERTIES OF CARBON MONOXIDE
- EXTRACTION OF METALS
- Slide 110
- CARBON DIOXIDE
- Slide 112
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- USES OF SILICONES
- Slide 131
- Slide 132
- USES OF SILICATES
- Slide 134
- Slide 135
- Slide 136
- USES OF ZEOLITES
- Slide 138
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