LOYOLA  COLLEGE (AUTONOMOUS), CHENNAI-600 034.

B.Sc. DEGREE  EXAMINATION  – chemistry

third  SEMESTER  – APRIL 2003

CH  3500/ che 504 physical chemistry – I

04.04.2002

1.00 – 4.00                                                                                          Max: 100 Marks

 

 

 

PART – A                                         (10 ´ 2 = 20) )

Answer ALL questions

 

1. What is an adiabatic process?
2. Examine whether dP is a complete differential for a system with the equation of state P(V-b) =RT where b,R are constats.
3. State: Trouton’s law.
4. What is the effect of pressure on the gaseous system PCl₅ PCl₃+Cl₂ at equilibrium?
5. Define enthalpy of combustion.
6. Mention the importance of the following.

(i)  plait point          (ii) tie line.

7. Calculate the number of components and degree of freedom in an aqueous solution

of Nacl.

8. Prove that a congruent melting point is an invariant point.
9. Define : Henry’s law.
10. Calculate the osmotic pressure of a 5% aqueous solution of glucose at 25°C

(mol.wt. of glucose=180 g mol^-1)

 

PART  – B                                         (8 ´5 = 40)

Answer any eight only

 

11. State and explain Hess’s law with an example.
12. Show that PV^r = constant.
13. 10 moles of an ideal gas expand isothermally and reversibly at 27°C from 10 lit to 100 lit. Calculate q, w, DE, DH and D
14. The standard free energy change of a chemical reaction at 100k is -10⁴

Calculate the equilibrium constant for the reaction.

 

15. Differentiate

• intensive and extensive variables.

(ii) bond energy and bond dissociation  energy.

16. How is absolute entropy of a gas determined using third law of thermodynamics?
17. State phase rule and discuss its derivation.

 

 

 

 

 

18. Explain the Pattinson’s process of desilverisation of lead.
19. Obtain a relation between osmotic pressure and uapour pressure lowering of an ideal solution.
20. State Raoult’s law and discuss it for a solution showing positive deviation.
21. The molar heat of vaporisation of water at 100°C is 40.585 kJ.  At what temperature

will a solution containing 5.60g of glucose per 1000g of water boil?(Mol. wt. of glucose = 180 gmol^–1)

 

 

 

PART  – C                            (4 ´ 10 = 40 Marks)

Answer any four only

 

22. Deduce four Maxwell’s equation from first principles. (10)
23. Derive (i) Kirchoff’s equation (5)

(ii) an expression for entropy of mixing of gases.                                    (5)

• a) For the reaction of the type

aA + bb cC +dD

derive the relation connecting DG and reaction quotient and deduce an expression for equilibrium constant.                                                                              (5)

 

1. b) Derive Gibbs-Helmboltz equation.  Mention its significance.                      (5)

 

25. State the distribution law. Discuss its thermodynamic derivation and explain

how it is altered during the association of the solute in one of the solvents.     (10)

 

26. Derive thermodynamically an expression connecting elevation of boiling point

of a solution and molality.

27. a) Discuss the salient features of the phase diagram of sulphur system.           (6)

 

1. How will you explain the variation of the mutual solubility of water and

phenol with temperature?                                                                              (4)

 

 

 

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                      LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034  B.Sc. DEGREE EXAMINATION – CHEMISTRY

AD 07

FIFTH SEMESTER – NOV 2006

         CH 5400 – POLYMER CHEMISTRY

(Also equivalent to CHE 400/CH518)

 

 

Date & Time : 30-10-2006/9.00-12.00     Dept. No.                                                       Max. : 100 Marks

 

 

PART – A

Answer ALL questions                                               (10 ´ 2 = 20 marks)

1. What are plastics? How are they classified?
2. How is cross–linked polymer prepared from trifunctional monomers?
3. What are the initiators used in free–radical polymerization?
4. How does nitrobenzene inhibit the action of a growing polymer chain?
5. Define living polymers.
6. Give any two examples for each anionic and cationic surfactants.
7. Write the advantages of suspension polymerization.
8. Define block copolymer and graft copolymer.
9. What are ‘antioxidants’ ? Give an example.
10. Define virgin polymers.

PART – B

Answer any EIGHT questions.                                   (8 ´ 5 = 40 marks)

11. Discuss the mechanism of cationic polymerization.
12. The polymer obtained by bulk polymerization is highly pure. Why? Explain.
13. Write short notes on interfacial condensation.
14. Explain the geometrical isomerism in polymers.
15. Differentiate random and chain–end polymer degradation.
16. What are the raw materials used to prepare polyethylene? Explain LDPE and HDPE.
17. Write a note on PMMA.
18. Discuss the factors affecting the c–c bond stability in thermal degradation.
19. Explain the different types of plastics.
20. Define the following terms.

(a)  Fillers        (b)  plasticizers            (c) stabilizers

21. Discuss the process of Die–casting.
22. Explain the advantages and disadvantages of extrusion moulding.

 

PART – C

Answer any FOUR questions.                                                (4 ´ 10 = 40 marks)

 

23.(a) Explain the mechanism of photo–initiated polymerization.  Write the role of
initiators in redox–oxidation reaction.

(b) How does the chain transfer takes place in free–radical polymerization?  (5 + 5)

24. Explain the bimetallic mechanism of Zieglar–Natta catalyst and its advantages.
25. Discuss emulsion polymerization.
26. (a) What is photodegradation? Explain the characteristics of photo stabilizers.

(b) Discuss the salient features of conducting polymers.                         (5 + 5)

27. (a) How is PET prepared? Why does its melting point high?

(b) Explain the preparation of nylon 6,6 and bakelite.                             (5 + 5)

28. What is FRP? Explain the different techniques used and mention their
    applications.

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             LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034  B.Sc. DEGREE EXAMINATION – CHEMISTRY

AD 09

FIFTH SEMESTER – NOV 2006

         CH 5500 – PHYSICAL CHEMISTRY – II

(Also equivalent to CHE 508)

 

 

Date & Time : 25-10-2006/9.00-12.00         Dept. No.                                                       Max. : 100 Marks

 

 

 

PART – A

Answer ALL questions.                                              (10 ´ 2 = 20 marks)

 

1. Write the anodic reaction of SCE.
2. Define concentration cell. Give an example for concentration cell without
   transference.
3. Derive the relation between emf and equilibrium constant.
4. Calculate the ionic strength of 0.01 m MgCl₂.
5. Explain how the use of KCl minimises liquid junction potential.
6. Differentiate order from molecularity.
7. What is the role of a catalyst in a reversible reaction?
8. “Adsorption if spontaneous must be exothermic”. Explain.
9. Calculate the value of one Einstein for a radiation of wavelength 300 nm.

(Use SI units).

10. The half life of a reaction is doubled on doubling the initial concentration.
    Deduce the order of the reaction and the units of rate constant.

 

PART – B

Answer any EIGHT questions.                                   (8 ´ 5 = 40 marks)

11. Explain an experimental method of determining the standard reduction potential
    of Zn electrode.
12. Explain the construction and working of Weston saturated cell.
13. Calculate the emf of the following cell Zn/Zn²⁺(0.05 m)½½Zn²⁺(0.005 m)½Zn.
14. How will you determine the K_sp of Ag₂CrO₄?
15. Explain the working of lead storage cell.
16. Mention Debye–Huckel equation. How will you verify it experimentally?
17. Derive an expression for the rate constant of a II order reaction with unequal
    concentrations ofHowH

reactants.

18. Explain the steps involved in thermal chain reactions with special reference to the
    dissociation of ethanal.  Indicate the rate expression for each step.
19. At 378.5° C the half life period for a I order reaction is 363 min and E_a is
    52 kcal/mol.  Calculate the time required for the reactant to be 75% decomposed
    at 450° C(R = 2 cal K^–1 mol^–1).
20. How is surface area of a solid determined using adsorption studies?
21. Explain “Skrabal” plots.
22. The decomposition of NH₃(g) on a tungsten filament follows first order kinetics
    at low pressure and zero order kinetics at high pressure.  Explain.
23. Explain “photosensitation” with two examples.

 

 

 

 

 

PART – C

Answer any FOUR questions.                                                (4 ´ 10 = 40 marks)

 

24. Explain any five types of electrodes. Derive expression for EMF of each of them.

25.(a) Explain the derivation of Nernst equation.

(b) Calculate the emf of Cu½Cu²⁺ (0.01 m) electrode at 25° C.

(Cu½Cu²⁺ : SRP = 0.34 V)

26. Explain the following

(a)  Determination of K_a of a weak acid by conductometric method.

(b)  Conductometric titration of a mixture of HCl and CH₃COOH  vs  Standard

NaOH.

27. Explain how the kinetic parameters for a single substrate enzymatic reaction can
    be obtained.
28. Explain the principle of “flash photolysis” with a block diagram.
29. Mention the postulates of ARRT and explain how the expression for rate constant
    can be obtained from ARRT.

 

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc.

LM 13

DEGREE EXAMINATION –CHEMISTRY

FIFTH SEMESTER – APRIL 2007

CH 5500 – PHYSICAL CHEMISTRY – II

 

 

Date & Time: 27/04/2007 / 1:00 – 4:00          Dept. No.                                                     Max. : 100 Marks

 

 

 

PART – A

Answer ALL questions.                                              (10 ´ 2 = 20 marks)

 

1. What is primary reference electrode? What is its SRP ?
2. Define chemical cell. Give an example.
3. Draw the graph of pH vs  volume of alkali added for a potentiometric acid–base  titration.
4. Calculate the ionic strength of 0.02M Na₂SO₄.
5. Define transport number.
6. What is a pseudo–order reaction? Give one example.
7. What is the effect of ionic strength on the rate constant of the reaction

S₂O₈^2– + 2I^–  ®   2SO₄^2– + I₂?

 

8. Mention the order and molecularity for a reaction proceeding through S_N2
   mechanism.
9. Define quantum yield of a photochemical reaction.
10. What is an adsorption isobar?

 

PART – B

Answer any EIGHT questions.                                   (8 ´ 5 = 40 marks)

 

11. Explain an experimental method of determining the standard reduction potential
    of Cu electrode.

 

12. Derive the relation between emf and (i) Equilibrium constant  (ii)  DS
13. Calculate the emf of the following cell Cd½Cd²⁺(0.01 m)½½Cd²⁺ (0.001 m)½Cd
14. How will you determine the K_sp of AgI.
15. Explain Arrhenius theory of electrolyte dissociation. Give evidences in favour of it.

 

16. Define equivalent conductance. Explain its variation with respect to
    concentration for  (i)  CH₃COOH  (ii)  HCl

 

17. The rate constant of a second order reaction of the type A + B ® products is
    given by the expression  log₁₀k  =   + 12.

The time is in minutes while the concentration of each is 0.008 M.  Calculate
the energy of activation and the half life at 10° C (Use R = 2 cal K^–1 mol^–1).

 

18. Write briefly on the kinetics of parallel reactions with one example.
19. Differentiate physisorption from chemisorption.
20. How is order of a reaction determined experimentally using “half life” method?

 

21. Compare collision theory of bimolecular reactions with ARRT.
22. Derive Langumir adsorption isotherm equation.
23. Explain chemiluminescence with two examples.

 

 

PART – C

Answer any FOUR questions.                                                (4 ´ 10 = 40 marks)

 

24. (a) Derive Nernst equation.

(b) Calculate the emf of hydrogen electrode at pH = 2.

 

25. (a) Explain the determination of pH using quinhydrone electrode.

(b) How will you prove electrochemically that mercurous ion exists as .

 

26. (a) Explain Debye theory of activity coefficient.

(b) Calculate the mean activity of 0.05 m Al₂(SO₄)_3.

 

27. Explain the kinetics of unimolecular reactions.

 

28  Derive Michaelis – Menton equation for a single substrate enzymatic reaction
and explain.

 

29. Explain the mechanism of bimolecular surface reactions with one example for
    each.

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

           B.Sc. DEGREE EXAMINATION – CHEMISTRY

GH 18

FIFTH SEMESTER – APRIL 2008

CH 5500 – PHYSICAL CHEMISTRY – II

 

 

 

Date : 28-04-08                  Dept. No.                                        Max. : 100 Marks

Time : 1:00 – 4:00

 

part – a

            Answer all questions.                                                            (10 ´ 2 = 20 marks)

 

1. Why can’t you use NaCl in salt bridge preparation of a galvanic cell?
2. For the cell reaction at 25° C, Zn½Zn²⁺⁺½½Cu²⁺½Cu     E°_cell = 1.10 V

Calculate equilibrium constant for the  reaction.

3. Define molar conductance of a solution.
4. What is transport number?
5. Calculate the ionic strength of 0.01 M KNO₃
6. 30% of a zero order is complete in 100 min. How long will it take for 60% completion of the reaction?
7. Mention the steps involved in a chain reaction
8. Differentiate adsorption from absorbtion
9. Mention the significance of the equation q =
10. State Grotthus – Drapper’s law.

 

PART – B

            Answer any EIGHT questions.                                            (8 x 5 = 40 marks)

 

11. Derive Nernst equation for a cell reaction.
12. Calculate E°_cell, E_cell, DG°_cell and DG_cell for

Cu½Cu²⁺(0.01 M)½½Ag⁺(0.001 M)½Ag at 298 K.  E°_red  Cu²⁺½Cu and Ag⁺½Ag are 0.34 V

and 0.8 V respectively.

13. Explain the construction and working of calomel electrode.
14. State and explain Kohlrausch’s law of independent migration of ions.
15. Write the electrode reactions and the net reaction of lead storage cell when it serves as source of current.
16. Explain the principle of conductometric acid-base titrations with an example.
17. Explain the mechanism of bimolecular surface reaction.
18. How does Λ vary with concentration for

(i) strong electrolyte        (ii) weak electrolyte

19. The rate of a reaction is doubled on increasing the temperature from 25° C to 35°  Calculate the activation energy of the reaction.  (R = 8.314 JK^-1mol^-1).
20. Derive an expression connecting rate constant and concentration of a II order5 reaction of the type 2A ®
21. Differentiate (i) order from molecularity (ii) EMF and potential difference.           (3 + 2)
22. Define quantum yield of a photochemical reaction. How is it determined?                        (2 + 3)

 

 

 

PART-C

   Answer any FOUR questions.                                                            (4 ´ 10 = 40 marks)

 

23.(a) Explain any two methods of determining order of a reaction.       (6)

(b) t_1/2 of C-14 is 5770 years.  Calculate the rate constant.  Starting from 100 mg
of  C-14 how much of it will remain at the end of 17,310 years.              (4)

24. Discuss the kinetics of unimolecular reaction with relevant derivation of the rate law.
25. Explain any two of the following: (5 + 5)

(a) Quinhydrone electrode and its use.

(b) Evaluation of thermodynamic quantities from EMF data.

(c) H₂-O₂ fuel cell.

(d) Determination of K_sp using conductometry.

26. (a) Explain how transport number of an ion be determined using moving
    boundary method?

(b) Explain the functioning of glass electrode.

27. Explain any two of the following:

(a) Electrochemical series

(b) Cells with transference

(c) Determination of EMF

(d) Weston Cadmium cell

28.(a) Explain the postulates of Langumir adsorption isotherm and hence derive the
equation.

(b) Write briefly on photosensitisation.

 

 

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

GH 10

THIRD SEMESTER – APRIL 2008

CH 3500 – PHYSICAL CHEMISTRY – I

 

 

 

Date : 26/04/2008                Dept. No.                                        Max. : 100 Marks

Time : 1:00 – 4:00

part – a

            answer ALL the questions.                                                 (10 ´ 2 = 20 marks)

 

1. Write van der Waal’s equation for ‘n’ moles of the gas and mention the terms involved.
2. Calculate DS for the vapourisation of 1 mole of H₂O(l) at 373 K.

DH_vap = 9720 cal/mol.

3. State Hess’s law of constant heat summation.
4. What is the effect of pressure on the system PCl_5(g) ⇌ PCl_3g) + Cl_2g) at equilibrium?
5. What is chemical potential? Is it extensive or intensive?
6. State reduced phase rule equation.
7. State Henry’s law.
8. What are colligative properties? Give two examples.
9. Define partition coefficient.
10. What is meant by thermodynamic equilibrium constant?

 

PART – B                             (8 ´ 5 = 40 marks)

              Answer any EIGHT questions.

 

11. State any five postulates of kinetic theory of gases.
12. Derive Gibb’s-Helmohltz equation.
13. Draw the phase diagram for water system and apply the phase rule equation to any one point, one line and one area.
14. 1 mole of an ideal, monoatomic gas expands isothermally and reversibly at 27°C from 10 to 100 lit. Calculate q, w, DE, DH and D
15. Differentiate bond energy from bond dissociation energy with a specific example.
16. State Raoult’s law and explain positive deviation from it.
17. How is osmotic pressure of a solution determined experimentally?
18. Derive the relation DG = DG° + RT ln Q and hence deduce an expression for thermodynamic equilibrium constant.
19. State III law of thermodynamics and explain.
20. Explain the phase diagram of phenol-water system.
21. Calculate the freezing point of 0.01 m aqueous solution of K₄[Fe(CN)₆] assuming 80% ionization. k_f for H₂O is 1.86 K kg mol^-1.
22. Derive Nernst distribution law.

 

 

PART – C

            Answer any FOUR questions.                                 (4 ´ 10 = 40 marks)

 

23. Derive Maxwell equations from first principle.
24. Deduce van der Waal’s equation.

 

25. Derive any two of the following. (5 + 5)

(a) PV^g = constant                              (b) Kirchoff’s equation

(c) relation between K_p and K_c             (d)

26. Draw the phase diagram of a simple eutectic system and discuss its salient features.
27. Derive thermodynamically the relation connecting elevation of boiling point of a solution and molality.
28. Explain any two of the following: (5 + 5)

(a) Gibb’s phase rule equation            (b) Azeotropes

(c) Joule-Thomson coefficient           (d) van’t Hoff factor.

 

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

DB 17

FIFTH SEMESTER – November 2008

CH 5500 – PHYSICAL CHEMISTRY – II

 

 

 

Date : 03-11-08                     Dept. No.                                        Max. : 100 Marks

Time : 9:00 – 12:00

 

PART – A

 

Answer ALL questions.                                  (10 x 2 = 20 marks)

 

1. What is a reference electrode? Give an example.

 

2. Define EMF.

 

3. What is meant by Hydrogen over voltage?

 

4. Calculate the ionic strength of 0.1M KCl.

 

5. Define order of a reaction.

 

6. What is a Psuedo-unimolecular reaction? Give an example.

 

7. Mention any two factors affecting the enzyme catalysis?

 

8. What is adsorption? Give an example.

 

9. Define quantum yield.

 

10. What is chemiluminesence?

 

PART – B

 

Answer any EIGHT questions.                                   (8 x 5 = 40 marks)

 

11. Explain the experimental method of determining the standard reduction potential

of Zn electrode.

 

12. Explain the working of Weston cell.

 

13. Calculate the EMF of the following electrochemical cell at 25^oC.

 

Cu, Cu²⁺ (a = 0.1 M)  ||  H⁺ (a = 0.01M),  H₂(0.95 atm); Pt E^o_xd cu²⁺| cu 0.34 volt

 

14. Discuss briefly the principle of polarography.

 

15. Explain the term decomposition potential. Discuss its application.

 

16. How is order of a reaction determined experimentally using half life method?

 

17. Explain the kinetics of unimolecular reaction using Luidemann theory.

 

18. Calculate the activation energy of a reaction whose rate constant is tripled by a 10^oC rise in temperature in the vicinity of 27^oC.

 

19. Derive Langmuir adsorption isotherm.

 

20. Discuss the general characteristics of catalytic reaction.

 

21. Derive an expression for rate constant of a second order reaction with equal concentration of

reactants.

 

22. Explain the basic concepts of photosensitized reactions.

 

PART – C

 

Answer ANY FOUR questions.                                 (4 x 10 = 40 marks)

 

23. a) Derive the Nernst equation for a cell reaction.                       (5)

 

1. Derive the emf of a concentration cell with transference. (5)

 

24. a) Explain the determination of pH using quinhydrone electrode.  (5)

 

1. b) How will you prove electrochemically that mercurous ion exists as Hg₂²⁺   (5)

 

25. Explain Debye Huckel Theory of strong electrolytes.

 

26. Explain the collision theory of bimolecular reactions. What are its limitations.

 

27. a) Explain the influence of ionic strength on the rates of ionic reactions.  (5)

 

1. b) Discuss on Absolute reaction rate theory.                                               (5)

 

28. Derive Michaelis – Menton equation for a single substrate enzymatic reaction and explain.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

   B.Sc. DEGREE EXAMINATION – CHEMISTRY

DB 06

THIRD SEMESTER – November 2008

CH 3500 – PHYSICAL CHEMISTRY – I

 

 

 

Date : 06-11-08                     Dept. No.                                        Max. : 100 Marks

Time : 1:00 – 4:00

PART – A

Answer ALL questions.                                  (10 x 2 = 20 marks)

 

1. State the first law of thermodynamics.

 

2. Write Van der Waals equation for ‘n’ moles if a gas.

 

3. Distinguish between state function and path function.

 

4. Explain the term Eutectic point with an example.

 

5. Define the congruent melting point.

 

6. Explain the term degrees of freedom.

 

7. What are azeotropes? Give an example.

 

8. State Raoult’s law.

 

9. Find the molal elevation constant of water which evaporates at 100^oC with the absorption of 40669.2 J per mole (R = 8.134 J K^-1 mol^-1).

 

10. 0.1 M aq. solution of KNO₃ shows an osmotic pressure of 4.5 atm at 300K, while the calculated one is 2.5 atm. What is the Van’t Hoff factor ‘i’ for the solution.

 

PART – B

Answer any EIGHT questions.                                   (8 x 5 = 40 marks)

 

11. State the postulate of the Kinetic theory of gases.

 

12. Define C_p and C_v. Derive the relationship between them for an ideal gas.

 

13. Prove that TV^γ-1 = constant for an adiabatic expansion of an ideal gas.

 

14. Calculate the entropy of mixing of one mole of oxygen gas and two moles of hydrogen gas, assuming that no chemical reaction occurs and the gas mixture behaves ideally.

 

15. Derive Clausius-Calpeyron ^equation.

 

16. Draw and explain the phase diagram of water system.

 

17. Give the general account of three components system.

 

18. Derive thermodynamically the Gibb’s phase rule.

 

19. Discuss the principle and application of Fractional distillation.

 

20. Explain the effect of adding NaCl to the CST of phenol water system.

 

21. Discuss the Van’t Hoff’s theory of dilute solutions.

 

22. The molar heat of vaporisation of water at 100⁰ C is 40.585 kJ mol^-1. At what temperature will a solution containing 5.60 g of glucose per 1000 g of water boil?

 

PART – C

Answer ANY FOUR questions.                                 (4 x 10 = 40 marks)

 

23. a) Derive Kirchoff’s equation.                            (5)

 

1. b) Explain Joule-Thomson effect.                       (5)

 

24. a) State and explain the third law of thermodynamics.  (5)

 

1. b) Derive Gibb’s Helmholtz equation.                            (5)

 

25. a) Explain the phase diagram of Pb-Ag system.             (4)

 

41. b) The vapour pressure of water at 100^oC is 760 mm. What will be the vapour pressure at 95^oC?  The heat of vaporisation of water in this temperature range is 41.27 kJ per mole.

(6)

26. Discuss the phase diagram of formation of compound with congruent melting point.

 

27. a) State and explain the Henry’s law.   How is it related to Raoult’s law?                    (5)

 

1. Write notes on steam distillation. (5)

 

28. a) Derive thermodynamically nernst distribution law.                                                    (6)
29. b) Explain one of its applications.                                                                                   (4)

 

 

 

      LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

WD 01

FIFTH SEMESTER – April 2009

CH 5500 – PHYSICAL CHEMISTRY – II

 

 

 

Date & Time: 16/04/2009 / 9:00 – 12:00    Dept. No.                                              Max. : 100 Marks

 

 

PART – A

Answer ALL questions                                                                                               (10 x 2 = 20)

1. Write calomel electrode reaction as reduction.
2. NaCl cannot be used in salt bridge. Why?
3. E^ocell is 1.10V for Zn + Cu²⁺ → Zn²⁺ + Cu. Calculate ∆G^o cell at 298K.
4. What are concentration cells? Give one example.
5. Define transport number of an ion.
6. 30% of a first order reaction is complete in 100 min. Calculate the rate constant of the reaction.
7. What is the effect of ionic strength on the rate constant of a reaction of the type A^– + B^– →

products in solution phase.

 

8. Mention the steps involved in a thermal chain reaction.

 

9. “Adsorption is spontaneous and mostly exothermic”.
10. Define quantum yield of a photochemical reaction.

PART – B

Answer any EIGHT questions                                                                  (8 x 5 = 40 marks)

11. Derive Nernst equation for a cell reaction and hence deduce an expression for equilibrium constant for the cell reaction.
12. Calculate E^o cell, Ecell, ∆G^o cell and ∆G cell for Zn|Zn²⁺ (0.01M) ||Ag⁺ (0.01M) |Ag at 298k. E^ored Zn⁺²|Zn – 076V and Ag⁺|Ag 0.8V.  Assume n = 2.  Write the electrode reactions.
13. Write down the electrode reactions in a) lead storage cell   b) H₂ – O₂ fuel cell.  Mention one salient feature for each.                                                                                 (3+2)
14. What is Weston – Cadmium cell? Explain its construction and indicate the electrode reactions.                                                                                                                      (2+2+1)
15. How is transport number of an ion determined experimentally?
16. Explain the variation of equivalent conductance with concentration for
17. a) strong electrolyte b) weak electrolyte in water with suitable graph. (2+2+1)
18. Differentiate order form molecularity.
19. Explain the principle of conductometric titrations with one example.
20. The rate of a first order reaction is doubled on increasing the temperature from 27^oC to 37^oC (R=8.314 JK^-1 mol^-1.)   Calculate the activation energy of the reaction.
21. State the postulates of Langumir adsorption isotherm and hence derive the equation. (2+3)
22. Write briefly on i) photosensitization ii) chemiluminescence.
23. Derive an expression for rate constant of a second order reaction of the type 2A →products.

PART – C

Answer any FOUR questions                                                   (4 x 10 = 40 marks)

23) a) Explain how ∆G^o, ∆H^o, ∆S^o of a cell reaction be determined using EMF measurements.    (6)

1. b) Explain the significance of electromotive series.                 (4)
2. Give an account of any two of the following a) types of electrodes with the relevant Nernst

equations.  b) determination of Ksp of a salt using EMF.  c) Principle for potentiometric acid –

base titrations.  d) standard hydrogen electrode.

25. a) Derive an expression for Ecell for a chemical cell with transference (6)
26. b) How is Ka of weak acid determined using conductance measurements?                         (4)
27. a) Explain any two methods of determining order of a reaction (6)
28. b) Discuss the mechanism of S_N2 reaction with an example. (4)
29. Explain the kinetics of single substrate enzymatic reaction. How are the kinetic parameterms

evaluated?                                                                                                                               (6+4)

28. Write notes on any two of the following (5+5)
29. a) Debye-Huckel theory of strong electrolytes
30. b) Principle of polarography
31. c) Quinhydrone electrode & its use.
32. d) Parallel reactions.

 

 

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      LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

WD 09

THIRD SEMESTER – April 2009

CH 3500 – PHYSICAL CHEMISTRY – I

 

 

 

Date & Time: 06/05/2009 / 9:00 – 12:00  Dept. No.                                                   Max. : 100 Marks

 

 

 

PART – A

Answer ALL the questions                                                                 (10 x 2 = 20 marks)

 

1. Distinguish C_p and C_v of an ideal gas.
2. Define: Integral heat of dilution.
3. Deduce the relationship between K_p and K_c for the following reaction

2NO(g) + O₂(g)     2NO₂(g)

4. Dissociation of NH₄Cl is represented by the equation

2NH₄Cl(s)      NH₃(g) + HCl(g)

What is the number of components for it if a start is made with (i) pure NH₄Cl    (ii) NH₄Cl  and either product of dissociation

5. State Le Chatelier’s principle.
6. Apply phase rule to the triple point of water.
7. State Hess’s law of heat of summation.
8. Calculate the root mean square velocity of O₂ molecule at 27°C.
9. “Addition of a non-volatile solute lowers the vapour pressure of a solution” – Offer a theoretical explanation for this statement.
10. State the Nernst distribution law.

PART – B

Answer any EIGHT questions                                                            ( 8 x 5 = 40 marks)

 

11. Show that the entropy of mixing of ideal gases is positive.
12. The standard enthalpy of formation of HCl gas at 25°C is -22.06 kcalmole^-1. Calculate the ΔE of formation at 25⁰C.
13. State third law of thermodynamics. Explain how the absolute entropy of a substance can be determined on the basis of the third law of thermodynamics.
14. State and derive Gibb’s phase rule.
15. Water gas reaction is represented by the equation

C_(s) + H₂O_(g)     CO_(g) + H_2(g)

1. What is the equilibrium law expression for the reaction?
2. State, giving reasons, how this equilibrium will shift if
3. all pressures are doubled
4. the temperature is increased

 

16. Deduce gas laws on the basis of the kinetic theory of gases.
17. State and explain Henry’s law. What are the limitations of this law?

 

 

 

 

18. What is meant by critical solution temperature? How can it be determined for phenol-water system? Explain the effect of addition of NaCl on the critical solution temperature.
19. How can the molecular mass of a nonvolatile solution be determined from freezing point measurements?
20. A 0.1formal solution of NaCl is found to be isotonic with a 1.10% solution of urea. Calculate the apparent degree of dissociation of NaCl.
21. Apply phase rule to Lead-Silver system and discuss the desilverisation of lead from this system.
22. Draw and explain the phase diagram of any three component system having one partially miscible pair.

PART – C

Answer any FOUR questions                                                                         ( 4 x 10 = 40 marks)

 

23. Derive Maxwell’s equations from basic thermodynamic ralations.
24. a. Derive Gibbs-Helmholtz equation.
25. The measured heats of neutralization of acetic acid, formic acid, hydrocyanic acid and hydrogen sulphide are 13.20, 13.40, 2.90 and 3.80 kcal per geq. respectively. Arrange these acids in the decreasing order of strength.
26. Draw the phase diagram of FeCl₃-H₂O system and describe its complete labeling. Explain, What do you understand by the isothermal evaporation of the solution.
27. a. State and explain Raoult’s law.
28. What are azeotropic mixtures? Give examples.
29. a. What are abnormal colligative properties? How will you calculate the vant Hoff factor and degree of dissociation of a solute from the measurement of colligative properties?
30. 0.9g of a solute was dissolved in 100ml of benzene at 25°C when its density is 0.879g/ml. The solution boiled 0.250°C higher than the boiling point of benzene. Molal elevation boiling point constant for benzene is 2.52 Kkgmol^-1. Calculate the molecular weight of the solute.

 

28. Derive thermodynamically the relation connecting elevation in boiling point of a solution of a non-volatile solute in a volatile solvent and its molality.

 

 

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LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc., DEGREE EXAMINATION – CHEMISTRY

FIFTH SEMESTER – NOVEMBER 2012

CH 5500 – PHYSICAL CHEMISTRY – II

 

 

 

Date : 03/11/2012             Dept. No.                                        Max. : 100 Marks

Time : 1:00 – 4:00

 

PART A

Answer All the questions:                                                                                                     10×2=20

 

1. Define EMF.
2. What is calomel electrode?
3. Calculate the ionic strength of 0.1M A1₂(SO₄)
4. What is concentration polarization?
5. Distinguish between order and molecularity.
6. Sketch the energy profile of a reaction and explain energy of activation.
7. Enlist the factors which influence enzyme catalysis.
8. Write the Langmuir adsorption isotherm.
9. Quantum yield of photochemical H₂ –C1₂ reaction is very high. Why?
10. State Einstein’s law of photochemical equivalence.

PART B

 

Answer any EIGHT of the following:                                                                                 8×5=40

 

11. Derive Nernst equation.
12. How will you determine _PH of a solution using glass electrode?
13. Describe the construction and working of Weston cell.
14. Write any one method of determining transference number.
15. Discuss Debye-Huckel theory of activity coefficients.
16. Explain reversible, consecutive with one example.
17. Radioactive strontium-90 has a half life of 28.8 years. How many years will it take for 99% of a given sample of strontium-90 to disintegrate?
18. Discuss the kinetics of unimolecular reactions using Lindemann theory.
19. Derive Michaelis – Menton equation.
20. List out the differences between chemisorptions and physisorption.
21. What are pseudo order reactions? Explain.
22. Deduce Langmuir adsorption isotherm.
23. Explain photosensitized reaction with an example.

PART C

Answer any FOUR of the following:                                                                                  4×10=40

 

24. a) Derive relationships between EMF and (i) ∆G (ii) ∆S.
25. b) How will you find the solubility product of AgCI by EMF measurements?
26. a) Write a note on potentiometric titrations.
27. b) Give the merits and demerits of DME.

 

26. a)Discuss Arrhenius theory of electrolytic dissociation.
27. b) Define equivalent conductance. How will it vary with dilution of

(i) a strong electrolyte.

(ii) a weak electrolyte.

 

27. a) Derive rate equation for a second order reaction of type 2A products.
28. b) Describe graphical method of determining order of a reaction.

 

28. Explain Absolute reaction rate theory.

 

29. a) Apply Langmuir adsorption isotherm to slightly adsorbed systems.
30. b) Discuss the applications of flash photolysis.

 

 

 

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