chapter 1-7 chemistry question bank for cet

5/14/2018 Chapter 1-7 Chemistry Question Bank for CET

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II YEAR PUCChapter 1: Metallurgy n81 . QuestionNo.1. Partition coefficient of Iodine between CC14 and water is 85 at298K. What does it mean?

h is 85 times more soluble in CC4 than in water at 298 K.2. State Nemst's Distribution law.

Correct statementDistribution of a solid between two immiscible solvents at constanttemperature.

3 . Mention one application of Nernst's distribution law.

Any suitable application4 . In Parke's process molten Zn is mixed with molten argentiferrous

lead. Why?Silver is 300 times more soluble in molten Zn than in molten Pb.

5 . How many times is Ag more soluble in molten Zn than in moltenPb at 800C?300 times

6 . Mention the method for the separation of Ag from Zn - Ag alloy.

By distillation7 . What is argentiferrous lead?

Lead containing Ag and Fe etc as impurities.

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8. What are Ellingham diagrams?

Correct definition9. Mention one application of Elling ham diagram in Metallurgy.

Anyone suitable application10. Why does theEllingham curve for the formulation of HgO show

steep rise at 356 C ?Mercury boils or phase change

11. ll.Go for the formation of metal oxides of metals A and B is -225Jand -300J respectively. Which one of these metals is a goodreducing agent?B. ll.Govalue for B is lower.

'12. Which oxide of carbon is more stable at temperature more than983K?

Ans: CO13. Why is the Ellingharn curve for y.) + 02 (8) ______...C02(8) is a

straight line almost parallel to temperature axis?Ans: ll.Go is almost constant.

14. E.D. for the formation of metal oxides of metals A and B is given indiagram. Which one of these metal oxides is least stable?

Ans: Metal oxide of A.15. Al reduces Cr201 to Cr. What is the sign of ll.Go for the reaction?

Ans: ll.Go for the reaction is negative.16. In Ellingham diagram, there is a sudden change in the slope of the

curve for the formation of some metal oxides. Why?

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Ans: Phase change17. Arrange the following metals in the increasing order of affinity

towards oxygen.Hg, Mg, Cr and FeAns: Hg < Fe < Cr


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25. Using Ellingham diagram, show that Cr20] is more stable thanFe203.

26. At a temperature less than 983 K. CO is a better reducing agent thancarbon. Explain with the help of Ellingham Diagram.

At low temperature, the plot of CO lies below the plot of carbon.27. Ag and Hg can be obtained by thermal decomposition of their

oxides. Assign reason with the help of Elling ham Diagram.

At lower temperature the plots Ag and Hg crosses IlGo=0 line.28. With the help of EUingham diagram. explain why chromium does

not reduce AhO] ?

Because AhO] is more stable than Cr20] at all temperatures.29. Mention any two salient features ofEUingham Diagram,

Any two features.30. What is the role of ingredients in the metallurgy of iron?

Lime stone - FluxCoke - Fuel I reducing agent

31. EIHngham diagram for the formation of metal oxides of A. Band Cis given in the diagram.

a) Which is the most effective reducing agent to reduce 'C' ?b) Which is the least stable metal oxide?

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a) Ab) C

32. Explain with an example, the selection of a reducing agent for ametal oxide based on Ellingham diagram.

Lower the E.C. for the formation of a metal oxide, greater is thereducing property of the metal. From the diagram we infer thatAhO) is more stable than Cr20) and hence AI can reduce CriOl tochromium.

33. Using Ellingham diagram, compare the relative stability of MgOand AhO).

Below 1500 C MgO is more stable than AhO). Above 1500C.AhO] is more stable than MgO.

34. "CO reduces Fe20l below 983 K". Justify it with help ofEllingham diagram.

Below 983 K the plot of CO lies below FClO).Therefore, CO has greater affinity to get oxidized and hence acts asa reducing agent, to reduce FClO).

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35. Mention the energetics. Write the equations occurring in Ucombustion zone of metallurgy of iron. Mention I

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6.H is negative. C + O2 -----+ CO236. Draw a neat labeled diagram of blast furnace.

Neat diagram with labeling

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37. With equations explain the reaction occurring in different zoneswith temperature ranges during the extraction of cast iron. Combustion zone - 1400" C to 1600"CC + 02 ____,. C02 t

CO2 + C ____,. 2COWith explanation. Reduction zone - 500" C - 700" CFClO) + 3CO ~ 2Fe + 3 C02 t

With explanation Slag formation - 8000 - 1000"CCaCO) ____,. CaO + C02CaD + Si02 ~ CaSiO]With explanation

38. State Nemst's distribution law. Describe Parke's process ofdisilverisation of lead.Correct statement / procedure.Molten Zn is added to molten lead at 800" C. Ag in molten leadpasses into molten Zn forms Zn - Ag alloy. On distillation Ag isremoved. By repeating the process 3 or 4 times to get more yield ofAg.

39. What are Ellingham diagrams? Sketch the Ellingham diagram forthe formation of MgO, HgO and CO.

Statement for Ellingham Diagram - 1 mark

Cbapter 2: Industrial Important Compounds

81. QuestionNo..1. "H2S gas cannot be dried by using conc. H2S04'. Assign reasons:

Conc. H2S04 oxidises HzS to yellow precipitate of sulphur.

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2. Name the chemical used to remove Arsenic impurity in the reacting Kgases in manufacture of H2S04 by contact process. Cite

AverageAns: Ferric hydroxide

3. NH3 gas is not dried by using cone. H 2SO... Why? UExplainAverage

NH3 is base reacts with cone. H2S04.4. Name the catalyst used in the manufacture of NH3 by Haber's

process.K

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Ans: Finely divided iron5 . Name the reagent used in the purification Bauxite ore by Bayer's

method.U

IdentifyAns: Sodium hydroxide

6. Name the electrolytic cell used in the manufacture of caustic soda. UIdentifyAverage

ADS: Nelson's cell7 . What is brine? K

RecallEasySaturated solution of sodium chloride.

8 . Mention the optimum temperature in the manufacture of NH] byHaber's process. KMention'

EasyAns: 4500 C to 5000 C

9. Name the gas liberated when Zn reacts with cone. H2S04. KRecallEasyAns: Sulphur dioxide

10. Name the gas liberated when Mg reacts with dil. H2S04. KRecallEasyAns: Hydrogen gas

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11. What is Oleum?

12. Name the gaseous product formed when conc. H2S04 react withformic acid.Ans: Carbon monoxide

13. Account for the use of asbestos diaphragm in the manufacture ofNaOH by Nelson cell.It prevents the recombination of products formed at Anode andCathode.

14. Name the byproducts fanned In the manufacture of NaOH byNelson cell.HydrogenChlorine

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reason.15. "Solid sodium hydroxide is stored in air-tight containers". Give A

Ans: NaOH is deliquescent.16. H2 gas is liberated at cathode in preference of sodium in Nelson

cell. Assign reason.

Discharge potential of H, is less than sodium.17. A colourless crystalline dicarboxylic acid on heating with conc.H2S04 gives carbon monoxide and carbon dioxide. Identify theacid.

Ans: Oxalic acid

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18. An yellow residue of sulphur is obtained when a colourless gastreated with cone. H2S04. Identify the gas.

Ans: (H2S) Hydrogen gas19. "Water is not added to cone. H2S04". Assign reason.

Due to extensive hydration, large amount of energy is liberated.20. Give the comparison of chromite ore.

Ans: FeOCr:zO)21. Which radical is detected by chromyl chloride test?

Ans: Chloride ion22. Name the two gases formed when cone. H2S04 oxidises carbon.

Carbon dioxide, Sulphur dioxide23. What is the role of cone, H2S04 in the following equation?~ , H . s o .HCOOH A ) CO +H10

Dehydrating agent24. What is the colour change noticed when Pot. Dichromate is treated

with potassium hydroxide?Orange red to yellow.

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25. S02 gas is passed through acidified K2Cr207 turns it green. Why? UIdentifyAverage'

Ans: Chromic sulphate

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26. "Cone. H2S04 acts as oxidizing agent". Illustrate.

Explanation with a suitable example.27. What happens with cone, H2S04 is added to KBr crystals?

Explanation with equation

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reasons.28. Steam is passed in manufacture of NaOH using Nelson cell. Give U

Explain1. To clear the pores ofU-shaped tube.2. To wann up the electrolyte thereby increases theconductivity .

29. Write the cell reactions occurring in Nelson cell in the manufactureof caustic soda..

NaCI --+Na++ CI-H20 W+OIrAt cathode, 2H++ 2C- ~ H2 (reduction)At anode, 2Cr --+Ch + 2C- (oxidation)

~O. Give two uses ofNH1.

Any two uses.31. What are the effects of pressure and temperature on the yield ofNH3 in Haber's process?

High pressure and low temperature increase the yield OfNH1.32. "Potassium dichromate acts as a very good oxidizing agent in acidicmedium". Illustrate.

Explanation with suitable example.

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33. Write the cathodic reaction in Nelson cell.

NaCI __,. Na+ + CI-H20 H++ OH-At cathode. 2W + 2C- --) H2 (reduction)

34. Give two industrial applications of potassium dichromate.

Any two suitable uses

35. How do you convert potassium dichromate to chromyl chloride?

Explanation and equationK2Cr207+ 4 KCI + 6H2S04 ___. 2C~Ch + 6K.HS04+ 3H20

36. Show that cone. H2S04 contains two OH groups using PCls.

OH

0 = 1 = 0LH2S04 + PCls --) ........ + POCl] + HCICblorosulphonic acidHSO]CI + PCls -----+ S02Ch +POCh +HCISulpholyl chloride

37. Give two industrial applications of H2S04.

Any two industrial applications.38. Convert sodium chromate to sodium dichromate. How is sodiumdichromate separated?

Explanation and equation2Na2Cr04 + H2S04 __,. Na2Cr207 +Na2S04 + H20On cooling the solution. less soluble Na2S separates out leavingbehind Na2Cr207.

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39. Convert sodium dichromate to potassium dichromate.

ExplanationNa2Cr207 +2KCI ----i> K2Cr207 + 2NaCI

40. Draw the flow chart diagram for the purification of reacting gasesin the manufacture of H2S04 by contact process.

Correct flow chart - 3 marks41. What is the role of lime during the roasting of chromite ore with

soda ash?

It makes the mass porous.42. Describe the manufacture of caustic soda by Nelson cell.

Diagram - 1 markConstruction - 1markCell reaction- 1markWorking - 1mark

43. Write the reactions involved in the manufacture of H2S04 startingfrom sulphur.

Each equation- 1 mark44. Describe the manufacture of H2S04 by contact process starting

from pure reacting gases or purified gases.Each step - 1mark

45. How is NH3 manufactured by Haber's process?

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Diagram - 1 markPrinciple - 1 markEach step - ImarkExplanation - 2 marks

46. How is potassium dichromate manufactured from chromite ore?

Every step - 1mark47. Why is potassium dichromate called primary standard in volumetric

analysis?

1. K2Cr207 is available in 100% pure crystalline state.2. The solution of K2Cr207 is unaffected by air and sunlight.

Hence its normality remains unchanged for long time.

Chapter 3 : Noble Gases81. QuestionNo.1. Who isolated the first Noble gas compound?

Neil Bartlett2. What is the principle behind in Dewar's adsorption method forseparation of Noble gases?

The extent of Adsorption increases with increase in atomic massand decrease in temperature

3 . Which is the least abundant Noble gas in the atmosphere?

Xenon

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4. Name the Noble gas which is not adsorbed by Activated coconutcharcoal.

Helium5. Name the noble bas whose compound gas was first prepared by

Neil Bartlett.

Xenon6. Name the Noble gas which does not have octet electronic

configuration.Helium

r " J . Why Neon bulbs are used as beacon lights?

Neon light penetrate through fog and mist.8. Name the reagent used to remove traces of 02 from rare gas

mixture.Alk pyrogallol

9. Name the Noble gas which is least abundant in atmosphere.

Xenon10. Name the Noble gas which has the greatest extent of adsorption on

coconut charcoal.

Xenon11. Name the noble gas which is radioactive.

Radon

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12. Name the Noble gas which is the most abundant in atmosphere.

Argon13. How is XePtF6 prepared?

.Correct explanation with equation

14. How are Helium and Neon separated from the mixture of Noblegases?Mixture of Noble gases kept in contact with Ch-Iat-100C, He, Neare unadsorbed. Mixture of He and Ne now passed another Ch"unit at 93 K. He is unadsorbed and pumped out. On heating thecharcoal unit Ne gets desorbed and collected separately.

15. Give two uses of He INe IAr I Kr I Xe IRn. (Anyone)

Any two uses (each)16. Give reason why Helium is not adsorbed by Activated Coconutcharcoal.

1. Low Van der waals forces of attraction between He atoms.2. Low critical temperature3. very low at mass

17. A mixture of 02 and He is used by deep sea diver for breathing.Give reason.

Use of He avoids the formation of "bends".18. Name the Noble gas that does not occur in the atmosphere.

Radon

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19. Neon bulbs are used in botanical gardens. Why?

It stimulates the growth of the plants.20. Identify A, B, C and D in the following flow chart.

Mixture of Noble gases kept in contactwith Ch I at NCor K

He +BUnadsorbed (-180"qIConnected to Cb-3At93KI

E+F+Gunadsorbed in Ch-l

CUnadsorbed DAdsf' in Ch- 3WannEvoved

A =173 K or-lOOo CB = Neon [Ne]C = He [Helium]D=Ne [Neon]

21. In Rayleigh-Ramsay method of isolation of noble gases from air.i) Show the need for an electric arc is struck between the

platinum electrodes.ii) What is the role of sodium hydroxide in the above

process? Write the equations involved.i) To combine N2 with 02 to fonn Nitric oxide N2 +O2 ~

2NOii) NaOH is used to absorb NOz formed2N02+ 2NaOH ~ NaN02 + NaNO] + H20

22. How are Noble gases isolated from air by Ramsay - Rayleighmethod?

Correct explanation with diagram.

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23. How are Noble gases separated by Dewar's charcoal adsorptionmethod?

Correct explanationMentioning temperature

Chapter 4: d-block ElementsSI. QuestionNo.1. What are d-block elements?

Correct definition - partially filled d-subshell.2 . Give the general electronic configuration of 3d - series elements.

[Ar]3d 1-10 481-23 . Give the electronic configuration of chromium.

[Ar]3dS 48'4. Which elements shows highest oxidation state among 3d- series

elements?

Mn5 . Name a compound in which manganese shows +7 oxidation state.

Potassium Permanganate

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6. Mention the oxidation state that exhibited by all the 3d-serieselements.

+27 . Zinc is not considered as transition element. Assign reason.

8 .No partially filled 3d- subshell in ground state or commonoxidation state.FeJ+ ion is more stable than Fe2+ ion. Assign reasons.

1. FeJ+ - [Ar] 3ds - half filled orbitals2. Fe2+ - [Ar] 3d6 - four 3d orbitalsAns: 5

9. Give an example for a transition metal compound in whichtransition metal exhibits zero oxidation state.

10. Most of the 3d-series metal compounds are colour. Why?

They have partially filled d-subshells.11. What type of magnetic behaviour is shown by the transition

elements containing unpaired electrons?

Paramagnetic behaviour

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12. Write the formula used to calculate the spin only magnetic.moment, KRecallEasy

Ii= . I n (n +2) Bm

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13. What is the unit of magnetic moment?

Bohr Magnaton Or (B.M.)14. Mention the magnetic behaviour of TfJ+.

Paramagnetic

IS. Which one of the following will be coloured in aqueous solution?T3+ V3+ c +1, U

16. What IS the trend in atomic size noticed among 3d-series oftransition elements?

Decreases first, remains constant and then increases.

17. Write a note on the catalytic behaviour of transition metals.

1. Variable oxidation states2. Vacant d-orbitals3. Larger surface area (any two)18. Mention two factors that are responsible for the formation ofcomplexes by 3d-series elements.

1. High charge and small size2. Vacant d-orbitals19. CUS04. 5H20 is coloured compound and ZnS04. 7H20 is acolourless compound. Why?

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1. CUS04. 5H20 - CU2+- contain unpaired electrons.2. ZnS04. 7H20 - Zn2+ - does not contain unpaired electrons.

20. Calculate the magnetic moment of Fe2+.

Fe2+ - 3d6 5so n =4 ( Y : t + Y : t marks)M = .In(n +2) (Ih mark)= .J4(4+2)= ..fi4= 4.90 B.M. ( Y : t mark)

21. Atomic radii of transition metals first decreases remains constantand then increases as we move from left to right along 3d-series.Explain.

1. due to increase in effective nuclear charge2. increase in screening effect of nuclear charge3. repulsive interaction between added electrons is more.

Chapter 5 : Co-ordination CompouDds

81. QuestionNo.1. Give the IUPAC name of[Co(en))]BrJ.

Tri ethylenediamine cobalt (III) bromide2 . What is the geometry of ferrocyanide ion?

Octahedral3. K2[Ni(CN)4] has square planar geometry. What is the hybridization

of the concentrated ion?

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4. In K3[Fe(CN)6] identity the species that satisfies both the primaryand secondary valency of central metal ion.

5 . Which one of these is an ligand?H20, 8CN-, 8042, ambidentate

seN"6. K2[HgI4] is dissolved in water. _How many ions per molecule of

the complex is released in aqueous solution?Three (3)

7 . Which one of these is a cationic complex?[Aq(NH3h]N03, K3[Fe(CN)61. [Ni(CO)4]

8 . Give an example for a bidentate ligand.

Anyone correct example. Eg. Ethylene diamine oxalate ion9 . What is the coordination number of chromium in [Cr(CnhCh]Br ?

Six10. Potassium cyanide ionizes to give CW, but Ka [Fe(CN)6] does not,

when dissolved in water. Assign reasons.

~[Fe(CN)6] contains (CN) in coordination sphere that is non-ionisable.

11. Name the species that satisfies the secondary valency of the metalion in cuprammonium sulphate.

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12. The coordination number of the following compounds is six.Which one of the following gives a white ppt. will aqueous silvernitrate?i) Co(NH3)4Ch ii) co (NH3)3ChCO(NH3)4Ch

1 3 . in waterK3[Fe(CN)6] . 3K+ + .....What is missing ion?

14. Identify the oxidation state of the metal in [Ni{CN)s)3- .

O. state is +2.(0. No. ofNi = +2)

15. Which one of the following complex has tetrahedral geometry?[Ni(CO)4]. [CU(NH3)4]S04. [Zn(H20)6]S04

[Ni(CO),,]16. Give an example for abidentate neutral ligand.

Anyone ego Ethylenediamine.17. What type of isomerism is exhibited by the following compounds?

[CO{CNhBrONO]CI and [Co (enhBrN02]Cl

Linkage isomerism - 1 mark18. Write a hydrate isomer for [Cr(H20)6]Ch.

19. For K3[CoCI6], identify the following:i) central metal ion, ii) the ligand, iii) coordination number ofcentral metal ion. iv) type of complex

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i)CO+3 ii) chloride (chloro) iii) 6 iv) anionic complex20. Show that [Ni(Co)4] satisfies EAN rule.

Count the e's around nickel atom - 1 mark.Match that with atomic number of nearest noble gas - 1 'mark

21. Mention two limitations of VBT for coordination compounds.

1. Cannot account for spectral properties.2. Relative stabilities of complexes.

22. Mention the magnetic behaviour ofthe following:i) [Ni(Co)4] ii) [CU(NH)4]S04i) Diamagnetic, ii) paramagnetic

23. Distinguish between primary and secondary valencies of a metal ina complex.

Any two differences.24. What is linkage isomerism of Coordination compounds? Give an

example.

Statement - 1 mark, Example - 1 mark25. Calculate the EAN of'the central metal ion in the complex

K2[NiCI4].

At. NONI(28) O. State Ni(+2) +No.1 of electrons from ligands (8)Answer - 1 mark

26. Draw the structure and state the hybridization of the central atom ofpotassium ferrocyanide.

. Structure - 1 mark, hybridization - 1 mark

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27. Write the postulates of valence bond theory of coordinationcompounds.

Any four points - (one mark each)28. With respect to potassium ferrocyanide mention

i) the oxidation state of eMIii) type of hybridization involvediii) the ligandiv) geometryv) magnetic propertyvi) coordination number

+2, d2sp3, C~, octahedral, diamagnetic, 6 - Y : z value point each29. Using VBT, account for the shape and magnetic property of

[Ni(CO)4].

Hybridization - 1 mark, shape - I mark, magnetic property - 1mark

30. Write the postulates of Wemer's theory for coordinationcompounds.

Three points - 1 value point each

Cbapter 6 : Cbemical Bonding81 . QuestionNo.

1. How are molecular orbitals formed?

By linear combination of atomic particles2. Name the two types of molecular orbitals formed.

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1. Bonding Molecular Orbital2. Antibonding Molecular Orbital

3 . Mention the maximum number of electrons that can beaccommodated in a molecular orbital.

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Two4 . Two atomic orbitals undergo additive linear combination. What

type of molecular orbitals are formed?U

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Bonding molecular orbital5. How does asymmetric combination of atomic orbitals take place? U

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It is formed by subtraction of the wave functions of two atomicorbitals. .6. Which type of molecular orbital is formed by symmetric K

combination of atomic orbitals?Bonding molecular orbital

7. Which type of molecular orbital is formed by asymmetric Kcombination of atomic orbitals? NameEasy

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Number of covalent bonds between two atoms in a molecule.9. Sketch o is molecular orbital. S

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10. Oxygen molecule is paramagnetic. Why?

It contains unpaired electrons in x* 2py and 1t2px orbitals.Or it contains unpaired electrons.

11. Write the electronic configuration of lithium molecule.

12. What is metallic bond?

The force that keeps the metal atoms together in a metal as a resultof the attraction between positive ions and surrounding freelymoving electronsOr correct definition

13. Valence electrons of metal atoms are freely moving in metals.Why?Due to low ionisation energy

14. Bond order of hydrogen molecule (H2) is 1,Ht is ~. Which ismore stable?

Hydrogen molecule15. Write electronic configuration of hydrogen molecule.

16. 1t*2py and 1t*2pz orbitals of oxygen molecule have one electroneach. Name the rule that expalins this arrangement.

Hund's rule

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17. Write electronic configuration of helium molecule.

18. Sketch the ols molecular orbital.

o ls19. He2 does not exist. Why?

Calculation of bond order (Imark)Inference (1 mark)

20. Give any two differences between bondingand antibondingmolecular orbitals.Each difference ( 1 mark)

21. How does electron gas theory explain electrical conductivity ofmetals?

According to electron gas theory, how electrons are present inmetals (1 mark)After applying electric field. how those electrons arrange (1 mark)

22. Calculate the bond order in lithium molecule.

Equation for calculating bond order (1 mark)Substitution and answer (1 mark)

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lustrous?23. With the help of electron gas theory, explain why metals are U

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24. How does electron gas theory explain malleability and ductility ofmetals?Defmition of gas theory (1 mark)Explanation (1mark)

25. Explain thermal conductivity of metals on the basis of electron seamodel.Definition of electron gas theory (1 mark)Explanation (1 mark)

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26. Draw the energy level diagram for molecular orbitals of lithium Smolecule. DrawEnergy level diagram (2 marks)

27. Draw the energy level diagram of molecular orbitals of hydrogenmolecule. Calculate the bond order.

Energy level diagram (1 mark)Bond order (1 mark)28. Explain electron sea model of metallic bond.

Explanation (2 marks)29. Describe the formation of bonding molecular orbitals by the linearcombination of atomic orbitals.. " Additive combination (1 mark)Wave equation (I mark)

30. Describe the formation of antibonding molecular orbitals by thelinear combination of atomic orbitals.

Substractive combination (1mark)Wave equation (l mark)

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31. Draw the energy level diagram for oxygen molecule. Calculate itsbond order and predict the magnetic property.

Energy level diagram (2 marks)Bond order (1mark)Magnetic property (1 mark)

Chapter 7: Chemical Kinetics81. QuestionNo.1. What is the unit of rate of reaction?

2 . Write the relation between energy of activation and velocityconstant of a reaction.k =A cE!a/RT

3 . What is the unit of concentration in reaction kinetics?

4. Define Order of a Reaction.

It is the sum of the powers of concentration terms in theexperimentally determined rate equation for the reaction.

5. How is half-period related to the initial concentration for nth orderreaction?

,,-Ia

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6 . Mention the order for alkali hydrolysis of methyl acetate.

27 . Half-life period of a reaction is inversely proportional to the initialconcentration of the reactant. What is the order of the reaction?

18 . Define Threshold Energy.

The minimum amount of energy possessed by the reactantmolecules to react to form products upon collision is calledThreshold Energy.9. The rate of reaction increases 4 times when the concentration of thereactant is doubled. What is the order of the reaction?

2 (two)10. Define half life period.

The time at which the molar concentration of a reactants getsreduced to exactly half of its initial value.11. Define Activation Energy.

The rmmmum extra energy that the normal reacting moleculesshould acquire to attain threshold energy to form products uponcollision.12. Define temperature coefficient of a reaction.

It is the ratio of velocity constant at (T + 10) k to velocity constantTk.

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13. Define Zero Order Reaction.

A Zero Order Reaction is one in which velocity of the reaction isindependent ofthe concentration of any of the reactants.

14. What is First Order Reaction?

A chemical reaction in which the rate is directly proportional to thefirst power of the concentration of the reactant is a first orderreaction.

15. Give an example for pseudo-first order reaction.

CH) + COOCH) + H20 Ir ~H] - COOH + CH)OHOr any other suitable example.Explanation in words, that is acid hydrolysis ofmetbyl acetate.

16. Find the overall order of a reaction with a rate equationV =k [A l2 [B]I .

317. Define pseudo first order reaction,

A chemical reaction of higher order can be converted into firstorder by taking the other reactants except one in large excess.

18. What is the effect of temperature on the rate of reaction?

Increases19. Give an example for 2ndorder reaction.

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CH)COOCH3 + NaOH ~ CH3COONa + CH30H orexplanation or any other suitable example.

20. Give an example for fractional order reaction.

CH)CHO ~ CIt. + COOr H2 + Br2 ~ 2HBrOr-any other suitable example

21. Give an example for zero order reaction.

Formation of hydrogen chloride in diffused sunlightOr H2 + Ch D { f f i I . K d s o m J t g ' " ) 2HClOr any other suitable example.

22. How is half life period related to velocity constant of a first orderreaction?

0.693tl/2= -_k23. When the temperature of a reaction increases by 20 degrees, by

what factor does the rate increase if the temperature coefficient is21

4 times24. If the rate of a reaction is independent of concentration of the

reactant, what is the order of the reaction?Zero

25. What is the order of the following reaction?R-COO-R'+NaOH ~ R-COONa+R'-OH

2 (two)26. Give the expression for the rate of reaction for a reaction,

2A ~ products, which follows zero order kinetics.v =k [A Jo

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27. Rate equation for a reaction is r = k {A]11l [8]3/2 what is overallorder of the reaction?

228. If the reaction between A and B gives C. and shows first order

kinetics with respect to A and second order kinetics with respect tob, write rate equation.r =k [A]I [8]2

29. What is the unit for velocity constant of a first order reaction?

30. Mention any two factors deciding the order of the reaction.

1. Mechanism (1 mark)2. Concentration (1 mark) or pressure

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Easy

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31. A first order reaction has a rate constant 3.2 x lO'~ min" calculate Ahalf-life period of the reaction. Calculation

Average0.693till = -k- (~mark)

Substitution ( ~ mark)Correct answer ( ~ mark)Unit ( ~ mark)

32. What is zero order reaction? Give an example.

Definition (1 mark)Example (1 mark)

33. The rate constant of a first order reaction is 0.002 sec". Calculatehalf life period.


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0.693tll2=-- (V, mark)kSubstitution ( Y :I mark)

Answer ( Y2mark)Unit ( Y1mark)

34. What is pseudo first order reaction? Give an example. UCite exampleAverage

Definition (1mark)Example (] mark)

35. Show that the rate of a first order reaction doubles when theconcentration of the reactants doubled. SJustifyAverage

rl =k [A] I (1) (Y1 mark)r2=k [2a] I (2) (V, mark)=> r2= 2.k[A]1 (Yzmark)

f2 = 2rl (Y 2 mark)36. The time for half -Iife of a first order reaction is found to be 30 A

min. Calculate the rate constant of a reaction. CalculationAverage

k= 0.693 ( Y : z mark)t1/2

Substitution ( V,mark)Correct answer ( V, mark)Unit ( Y1mark)

37. The rate constant of a first order reaction is 0.01386 min-I. ACalculate the time required for the initial concentration of 1 mol Calculationdm-3 to get reduced to 0.5 mol dm", Average

( _ 0.693)till - kEquation ( Y 2 mark)Substitution ( Y2mark)Correct answer ( V,mark)Unit ( Y 2 mark)

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38. If half life of a first order reaction is 100 sees, calculate the rateconstant of a reaction at 298 K.

K - 0.693 (1/ k)- -- nmar1112

Substitution ( ~ mark)Answer ( !4 mark)Unit ( Ylmark)

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39. The rate of reaction increases 4 times, when the concentration of the Areactant is doubled. Calculate the order of the reaction. Calculationro c [At ( !4mark)4 IX: [2]" ( !4 mark)2 2 oc [2t ( ~mark):. n=2 ( !4mark)

40. A first order reaction takes 50 minutes for 50% completion.Calculate velocity constant.

Formula -!4 markSubstitution - YlmarkCorrect answer - Y : t markUnit - Ylmark

41. In a first order reaction, the concentration of reactant reduced fromto mol/dm1 to 5 mol/drrr' in 40 minutes. Calculate rate constant.Formula ( Y : t mark)Substitution ( Y : 1 mark)Correct answer ( !4 mark)Unit ( Y : t mark)

42. Describe the graphical method for the determination of order of thereaction.

1. Graph for the determination of order ( 1mark)2. Explanation (2 marks)

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------ -----

43. Describe the Ostwald isolation method for the detennination oforder of the reaction.

1. for r x 4 having two or more reactants with general equation(1 mark)2. Explanation (2 marks)

44. Explain the influence of +ve catalyst on the rate of reaction with thehelp of energy profile diagram.

Energy profile diagram ( 1mark)Catalyst provides alternate path (1mark)Ea decreases ( Imark)

45. Calculate the energy of activation if rate constant of a reaction isdoubled when the temperature is increased from 300 to 310 k.[R=8.8324 Jk-Imol"]

Log k2 = Eo [T2 - ~ ] (1mark)kl 2.303 R ~ T2Substitution ( 1mark)Correct answer with unit (1 mark)(53598 s1mole = 53_598 kllmole)

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4 6_ Derive an expression for velocity constant for a first order reaction. UDerivationAverage

Upto rate equation with concentration of the reactionr = k [A]I (1mark)Upto - Ln (a-x) = kT + C (1 mark)Finding C. (lmark)Final expression (1 mark)

47. Show that for an I-order reaction, the value Oft3/4 is twice the valueOft1fl

k 2.303 1 a (1 k)3/4 = -_ og mar13/4 (a - x)= 2.303 log 4

13/4

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k 2.303 1 100112= -- og-t\12 50

2.303 I 2=- og1112

(1 mark)

Relation (1 mark)h , . =2 tll2 (1 mark)48. The rate constant for a reaction at 298 K and 318 K are 0.00325sec" and 0.01325s1 respectively. Calculate the energy of activation

(k = 8.314 J k' mol")

I k ;. Ea [ T 2 ~ 1; ]og - = (1 mark)k\ 2.303 R 1; T 2Substitution and simplification (2 marks)Answer and unit (1 mark)

49. 75% of first order r x n is completed in 72 min. Calculate the halflife period of the reaction.

k 2.303 I a ( 1/ k)= -- og-- hmar7 a-xSubstitution ( Yl mark)Correct answer with unit for k ( 1 mark)0.693tll2 = -- (Y l mark)kSubstitution ( ~ mark)Correct answer with unit (1 mark)

50. A first order r x n is 25% completed in 30 min. Calculate a)specific r x n rate, b) time required for 75% r x n to be completed.

E . k 2.303 1 a 1/ k)quatton, = -- og -- (7] mar7 a-xSubstitution ( Y : t mark)Correct value of k with unit ( 1mark)

Equation % M [ t1S% = = 2.~03 log : ]Substitution ( ~ mark)Correct answer with unit (1mark)

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51. Show that the time required for 99% completion of reaction is twicethe time taken for 90% completion.k = 2.303 log_Q_

t9 9 Q - xk = 2.303 log 1O 0

19 9 1k= 2.303 x 2 (1)

19 9k = 2.303 log 100

19 0 10k= 2.303 x 1 (2)1 9 f JRelate (1) and (2)2.303 x 2 = 2.39 x 1

19 9 1 9 f J:. t99 = 2l9o ( 1 mark)

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(4 marks)

52. A first order reaction is 40% completed at the end of 50 minutes. AWhat is the value of rate constraint? In how many minutes will be Calculationthe reaction 80% completed? Average

Calculation ofk :Formula = ~ markSubstitution =~markCorrect answer = Y z markUnit = ~ markCalculation of t : 2.303 100Formula =~~ t8O-1 =-- log ----I (l00 - 20)Substitution = Y; markCorrect answer = Y 2 markUnit = ~ mark

53. The rate constant of a first order r x n is 2.3 x 10-4 SI. Calculate thetime taken for completion of2l3n1 of the r x n.

ACalculateEquation (1 mark)Substitution and simplification (2 marks)Correct answer ( Y 2 mark)Unit ( Y J mark)

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54. A first order r x n 50% completed in 30 min. at 27' C and 10 min at47 C. Calculate energy of activation(R =8.314 Jk1 mol").

Calculation of rate constantkl = 0.693 (Yl mark)

1112Answer ( Y ; z mark)Similarly k2 (1 mark)Calculation of Ea with unit (2 marks)

55. The rate constant of a reaction at 25 C is 3.5 x 10 -3 Calculate thetemperature coefficient and rate constant at 35 C, given Ea = 52.3kl. k Eo [ T - T. ]log _ _ _ l _ = 2 I ( 1 mark)kl 2.303 R ~ r,Substitution and calculation ( Y a mark + Y ; z mark)

k :log _2 = 0.2975klk 2 = Antilog 0.2975 (1 mark)kl~ = 1.984klk2 = 1.984 x 3.5 x 10-3;;:: 6.94 x i o - 3 (I mark)

56. The energy of activation of a certain reaction is 11400 J _ Velocityconstant at 373 k is 0.75 X 10-1 min-I. What is velocity constant at473 k?Formula (1 mark)Substitution (1 mark)Calculation ofk2 (2 marks)

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