LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034

B.Sc. DEGREE EXAMINATION – CHEMISTRY

FOURTH SEMESTER – APRIL 2012

CH 4502 – ELECTROCHEMISTRY

 

 

 

Date : 21-04-2012              Dept. No.                                        Max. : 100 Marks

Time : 1:00 – 4:00

 

PART – A

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

 

1. Define electromotive series.
2. What is a primary reference electrode?
3. Write the relationship between ΔG and  EMF.
4. What are commercial cells? Give its applications.
5. What is Van’t Hoff factor?
6. Define ionic mobility.
7. Define equivalent conductance at infinite dilution.
8. What is cell constant?
9. What is meant by polarisation?
10. Write down the Ilkovic equation and mention the terms involved in it.

 

PART – B

 

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

 

11. What is meant by standard electrode potential? How could you determine the standard

electrode potential of Copper electrode?

12. State Faraday’s law of electrolysis. and explain.
13. What is the reduction potential of a half-cell consisting of zinc electrode in 0.015M ZnSO₄

solution  at 25^oC, E^o­­_red of zn²⁺ ½zn -0.763 v.

14. Explain the principle involved in the precipitation titration by potentiometry.
15. Derive Nernst equation.
16. Explain the classification of electrochemical cells with one example for each
17. A moving boundary experiment was carried out with a 0.01 M solution of KCl

(қ=1.29 Sm^-1), using CdCl₂ as the indicator electrolyte.  A current of 5.21 mA was passed through the

tube of 0.230 cm² cross-sectional area.  It was observed that the boundary moved through 4.16 cm in

one hr.   Calculate the mobility of the K⁺ ion.

18. Explain the variation of specific conductance with concentration.
19. How will you determine the solubility of a sparingly soluble salt by conductivity

measurements?

20. Discuss Debye Huckel theory of strong electrolytes.
21. Describe how the electrolytic separations of metals are carried out.
22. State and explain kohlrausch’s law.

 

PART – C

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

 

23. Explain the following :

(i)   Amalgam electrode

(ii)  Saturated calomel electrode

 

24. Explain any four applications of EMF.

 

25. How the p^H of a solution can be determined using a glass electrode? Explain.

 

26. What are concentration cells? Derive an expression for the EMF of a concentration

cell without transference.

 

27. (i) Discuss Arrhenius theory of electrolytic dissociation.

(ii) How will you determine the transference number by moving boundary method?

 

28. (i) Explain any two applications of conductivity measurements.

(ii)   Explain the principle of polarography.

 

 

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