ib chemistry on properties of transition metal and magnetism
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Periodic Table of elements – divided into s, p, d, f blocks
p block • p orbital partially fill
d block • d orbital partially filled • transition element
f block • f orbital partially fill
s block • s orbital partially fill
Periodic Table – s, p d, f block element s block elements • s orbitals partially fill
p block elements • p orbital partially fill
d block elements • d orbitals partially fill • transition elements
1 H 1s1
2 He 1s2
11 Na [Ne] 3s1
12 Mg [Ne] 3s2
5 B [He] 2s2 2p1
6 C [He] 2s2 2p2
7 N [He] 2s2 2p3
8 O [He] 2s2 2p4
9 F [He] 2s2 2p5
10 Ne [He] 2s2 2p6
13 Al [Ne] 3s2 3p1
14 Si [Ne] 3s2 3p2
15 P [Ne] 3s2 3p3
16 S [Ne] 3s2 3p4
17 CI [Ne] 3s2 3p5
18 Ar [Ne] 3s2 3p6
19 K [Ar] 4s1
20 Ca [Ar] 4s2
21 Sc [Ar] 4s2 3d1
22 Ti [Ar] 4s2 3d2
23 V [Ar] 4s2 3d3
24 Cr [Ar] 4s1 3d5
25 Mn [Ar] 4s2 3d5
26 Fe [Ar] 4s2 3d6
27 Co [Ar] 4s2 3d7
28 Ni [Ar] 4s2 3d8
29 Cu [Ar] 4s1 3d10
30 Zn [Ar] 4s2 3d10
n = 2 period 2
3 Li [He] 2s1
4 Be [He] 2s2
Click here video s,p,d,f blocks, Click here video on s,p,d,f notation Click here electron structure
Video on electron configuration
f block elements • f orbitals partially fill
Periodic Table – s, p d, f blocks element
Electron structure Chromium d block (Period 4)
1s2 2s2 2p6 3s2 3p6 4s1 3d5
[Ar] 4s1 3d5
Electron structure Germanium p block, Gp 14 (Period 4)
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p2
[Ar] 4s2 3d10 4p2
Electron structure Lead p block, Gp 14 (Period 6)
1s2 2s2 2p6 3s2 3p6 3d104s2 4p6 5s2 4d10 5p6 6s2 4f14 5d106p2
[Xe] 6s2 4f14 5d10 6p2
Electron structure Iodine p block, Gp 7 (Period 5)
1s2 2s2 2p6 3s2 3p6 3d104s2 4p6 5s2 4d10 5p5
[Kr] 5s2 4d10 5p5
Electron structure Cadmium d block (Period 5)
1s2 2s2 2p6 3s2 3p6 3d104s2 4p6 5s2 4d10
[Kr] 5s2 4d10
Electron structure Mercury d block (Period 6)
1s2 2s2 2p6 3s2 3p6 3d104s2 4p6 5s2 4d10 5p6 6s2 4f14 5d10
[Xe] 6s2 4f14 5d10
Gp 14 -4 valence electron Gp 17 - 7 valence electron
Gp 14 - 4 valence electron d block – d partially filled d block – d partially filled
d block – d partially filled
О
О
О
О
О
О
3d
Nuclear charge increase IE increase slowly
3d elec added to 3d sub level
3d elec – shield the outer 4s elec from nuclear charge
Ionization Energy – Transition metal Why IE increases slowly across ? IE Transition metal
Sc Ti V Cr Mn Fe Co
Period 4
Ni Cu
Shielding nuclear charge by 3d electron
+21 +22 +23 +24 +25 +26 +27 +28 +29
4s
Sc Ti V Cr Mn Fe Co Ni Cu Zn
+21 +22 +23 +24 +25 +26 +27 +28 +29 +30
Nuclear pull
Shielding by 3d electron Shielding by 3d electron
↓ Balance increase in nuclear charge
↓ Small increase in IE
↓ Easier to lose outer electron
↓ Variable oxidation state
Transition Metal (d block )
Across period
Cr - 4s13d5 • half filled more stable
Cu - 4s13d10 • fully filled more stable
Ca 4s2
K 4s1
Transition metal have partially fill 3d orbital • 3d and 4s electron can be lost easily • electron fill from 4s first then 3d • electron lost from 4s first then 3d • 3d and 4s energy level close together (similar in energy)
Filling electron- 4s level lower, fill first Losing electron- 4s higher, lose first
3d
4s
d block element with half/partially fill d orbital / sublevel in one or more of its oxidation states
Partially fill d orbital
Lose electron
↓
Formation ions
Sc3+
4s03d0 Zn 2+
4s03d10
Zn → Zn2+ 4s23d10 4s0 3d10
fully fill d orbital
Sc → Sc 3+ 4s23d1 4s0 3d0
empty d orbital
Transition Metal (d block )
NOT Transition element.
NOT Transition element.
О
О
Transition Metal
Physical properties Chemical properties
Element properties Atomic properties
• High electrical/thermal conductivity • High melting point • Malleable • Ductile • Ferromagnetic
• Ionization energy • Atomic size • Electronegativity
Transition Metal ( d block)
Gp 1 Gp 17
Sc
Ionization energy ↓
IE increase ↑ slowly ↓
Shielding of nuclear charge by 3d elec
↓ Electrostatic force
attraction ↓
Atomic size ↓
Decrease ↓ slowly ↓
Shielding of outer electron from
nuclear charge by 3d elec
Electronegativity ↓
EN increase ↑ slowly
Physical Properties
Zn
EN increase ↑
Atomic size decrease ↓
IE increase ↑
• Formation of complex ion • Formation coloured complexes
• Variable oxidation states • Catalytic activity
Formation complex ion Formation coloured complexes
Catalytic activity Variable Oxidation states
molecule adsorp on
surface catalyst
V Cr Mn Fe Co Ni
+2 +2 +2 +2 +2 +2
+3 +3 +3 +3 +3 +3
+4 +4 +4 +4 +4 +4
+5 +5 +5 +5 +5
+6 +6 +6
+7
Transition Metal – Variable Oxidation States
+3 +3 +3 +3 +3 +3
+2 +2 +2 +2 +2
+4 +4 +5
+2
+6 +6 +7
+2
+3
+4
+5
+6
+7
ScCI3 TiCI3 VCI3 CrCI3
MnCI3
FeCI3
CrCI2
MnCI2
FeCI2 CoCI2 NiCI2 CuCI2 ZnCI2
TiCI4
MnCI4 V2O5
Cr2O72-
+2
(VO2)2+
(MnO4)2-
(MnO4)-
oxides oxyanion
chlorides
+2 oxidation state more common +3 oxidation state more common
+3
CoCI3
Oxidation state Mn is highest +7
Highest oxidation state exist
↓
Element bond to oxygen
(oxide/oxyanion)
Oxidation state +2 common (Co → Zn)
↓
Harder to lose electron
↓
Nuclear charge (NC ↑) from Co - Zn
Oxidation state +3 common (Sc → Fe)
↓
Easier to lose electron
↓
Nuclear charge (NC ↓) from Sc - Fe
Transition metal – variable oxidation state
↓
4s and 3d orbital close in energy
↓
Easy to lose electron from 4s and 3d level
Ionic bond – more common for lower oxi states
TiCI2 – Ionic bond
Covalent bond – more common for higher oxi states
TiCI4 – Covalent bond
Highest oxidation states – bind to oxygen
Transition Metal
Formation coloured complexes Variable Oxidation states
Sc Ti V Cr Mn Fe Co Ni Cu Zn
+1
+2 +2 +2 +2 +2 +2 +2 +2 +2 +2
+3 +3 +3 +3 +3 +3 +3 +3
+4 +4 +4 +4 +4 +4 +4
+5 +5 +5 +5 +5
+6 +6 +6
+7
+3- most common
oxi state
+ 2- most common
oxi state
+ 7- Highest
oxi state
Click here vanadium ion complexes Click here nickel ion complexes
V5+/ VO2+ - yellow
V4+/ VO2+ - blue V3+ - green V2+ - violet
NiCI2 - Yellow NiSO4 - Green Ni(NO3)2
- Violet NiS - Black
Diff oxidation states
Colour formation
Nature of transition metal
Oxidation state
Diff ligands Shape Stereochemistry
Diff ligand Diff metals
MnCI2 - Pink MnSO4 - Red MnO2 - Black MnO4
- - Purple
Cr2O3 - Green CrO4
2- - Yellow
CrO3 - Red
Cr2O72-
- Orange
Shape/ Stereochemistry
Tetrahedral Octahedral
Blue Yellow
Transition Metal ion • High charged density metal ion • Partially fill 3d orbital • Attract to ligand • Form dative/co-ordinate bond (lone pair from ligand)
Ligand • Neutral/anion species that donate lone pair/non bonding electron pair to metal ion • Lewis base, lone pair donor – dative bond with metal ion
Ligand
+2
Formation complex ion
Transition Metal ion
Neutral ligand Anion ligand
H2O
NH3
CO
CI–
CN–
O2-
OH–
SCN–
: CI :
: .
Monodentate Bidentate
Polydentate
C2O42- C2H4(NH2)2
Drawing complex ion • Overall charged on complex ion • Metal ion in center (+ve charged) • Ligand attach • Dative bond from ligand
+3
4 water ligand attach 4 dative bond Coordination number = 4
6 water ligand attach 6 dative bond Coordination number = 6
Transition metal + ligand = Complex Ion
Coordination number
Shape Complex ion (metal + ligand)
Ligand (charged)
Metal ion (Oxidation #)
Overall charge on complex ion
linear [Cu(CI2)]- CI = -1 +1 - 1
[Ag(NH3)2]+ NH3 = 0 +1 + 1
[Ag(CN)2]- CN = -1 +1 - 1
Square planar
[Cu(CI)4]2- CI = -1 +2 - 2
[Cu(NH3)4]2+ NH3 = 0 +2 +2
[Co(CI)4]2- CI = -1 +2 - 2
Tetrahedral [Cu(CI)4]2- CI = -1 +2 - 2
[Zn(NH3)4]2+ NH3 = 0 +2 + 2
[Mn(CI)4]2- CI = -1 +2 - 2
Octahedral [ Cu(H2O)6]2+ H2O = 0 +2 + 2
[Fe(OH)3(H2O)3] OH = -1 H2O = 0
+3 o
[Fe(CN)6]3- CN = -1 +3 - 3
[Cr(NH3)4CI2]+ NH3 = 0 CI = -1
+3 + 1
Types of ligand: • Monodentate – 1 lone pair electron donor – H2O, F-, CI-, NH3, OH-, SCN- CN-
• Bidentate – 2 lone pair electron donor –1,2 diaminoethane H2NCH2CH2NH2, ethanedioate (C2O4)2-
•Polydentate – 6 lone pair electron donor – EDTA4- (ethylenediaminetetraacetic acid)
Complex ion with diff metal ion, ligand, oxidation state and overall charge
Mn+ L: :L
Mn+ :L
:L
L:
L:
Mn+
:L
:L
:L :L
Mn+
:L
:L
:L
:L
:L
:L
Coordination number – number of ligand around central ion
2
4
4
6
Ligand • Neutral/anion species that donate lone pair/non bonding electron pair to metal ion • Lewis base, lone pair donor – dative bond with metal ion
Neutral ligand Anion ligand
H2O
NH3
CO
CI–
CN–
O2-
OH–
SCN–
: CI : : .
Monodentate
Bidentate Polydentate
C2O42- C2H4(NH2)2
Ligand displacement
Co/CN > en > NH3 > SCN- > H2O > C2O42- > OH- > F- > CI- > Br- > I-
Spectrochemical series
Tetraaqua copper(II) ion
H2O displace by CI-
2+
CI- displace by NH3
Tetrachloro copper(II) ion
Stronger ligand displace weaker ligand
Tetraamine copper(II) ion
О
О
Stronger
ligand
Stronger
ligand
Chelating agent EDTA – for removal of Ca2+
• Prevent blood clotting • Detoxify by removing heavy metal poisoning
4s
3d
Magnetic properties of transition metals
Paired electron – spin cancel – NO net magnetic effect
Ti V Cr Mn Fe Co
Diamagnetism ↓
Paired electron ↓
No Net magnetic effect (Repel by magnetic field)
Ni Zn
Spin cancel
Sc
Spinning electron in atom – behave like tiny magnet
Unpaired electron – net spin – Magnetic effect
Spin cancel Net spin
Paramagnetism ↓
Unpaired electron ↓
Net magnetic effect (Attract by magnetic field)
Material
Diamagnetic Paramagnetic Ferromagnetic
• Iron • Cobalt • Nickel
Zn2+ Mn2+
Click here paramagnetism Click here paramagnetism Click here levitation bismuth Click here levitation
4s
3d
Magnetic properties of transition metal
Ti V Cr Mn Fe Co
Diamagnetism ↓
Paired electron ↓
No Net magnetic effect (Repel by magnetic field)
Zn
Spin cancel Net spin
Sc
pyrolytic graphite
Spin cancel Spin cancel
Paramagnetism ↓
Unpaired electron ↓
Net magnetic effect (Attract by magnetic field)
Diamagnetic Paramagnetic
Click here levitation bismuth Click here levitation
Click here paramagnetism measurement
Vs
Bismuth
Click here paramagnetism
Strong diamagnetic materials
Pt/Pd surface
Transition Metal – Catalytic Activity
Catalytic Properties of Transition metal • Variable oxidation state - lose and gain electron easily. • Use 3d and 4s electrons to form weak bond. • Act as Homogeneous or Heterogenous catalyst – lower activation energy • Homogeneous catalyst – catalyst and reactant in same phase/state • Heterogeneous catalyst – catalyst and reactant in diff phase/state • Heterogenous catalyst- Metal surface provide active site (lower Ea ) • Surface catalyst bring molecule together (close contact) -bond breaking/making easier
Transition metal as catalyst with diff oxidation states 2H2O2 + Fe2+ → 2H2O+O2+Fe3+
H2O2+Fe2+→H2O + O2 + Fe3+
Fe3+ + I - → Fe2+ + I2
Fe2+ ↔ Fe3+
Rxn slow if only I- is added H2O2 + I- → I2 + H2O + O2
Rxn speed up if Fe2+/Fe3+ added Fe2+ change to Fe3+ and is change back to Fe2+ again
recycle
molecule adsorp on
surface catalyst
Pt/Pd surface
Bond break
Bond making
3+
CH2 = CH2 + H2 → CH3 - CH3
Nickel catalyst
Without
catalyst, Ea
CH2= CH2 + H2 CH3 - CH3
Surface of catalyst for adsorption
With catalyst, Ea
adsorption H2
adsorption C2H4
bond breaking making
desorption C2H6
Fe2+ catalyst How catalyst work ?
Activation energy
• Haber Process – Production ammonia for fertiliser/ agriculture
3H2 + N2 → 2NH3
Uses of transition metal as catalyst in industrial process
Iron , Fe
Vanadium (V) oxide, V2O5
Nickel, Ni
Manganese (IV) oxide, MnO2
Platinum/Palladium, Pt/Pd Cobalt, Co3+
Iron , Fe2+ ion
Contact Process – Sulphuric acid/batteries 2SO2 + O2 → 2SO3
Hydrogenation Process- Margerine and trans fat
C2H4 + H2 → C2H6
Hydrogen peroxide decomposition – O2 production
2H2O2→ 2H2O + O2
Catalytic converter – Convertion to CO2 and N2
2CO + 2NO → 2CO2 + N2
Biological enzyme Hemoglobin – transport oxygen
Vitamin B12 – RBC production
NH3
Co3+
O2 Fe2+
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