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PG – 724

*PG724* IV Semester M.Sc. Examination, July 2013 (R.S.) (2006-2007 Onwards Scheme) CHEMISTRY C-401-PC : Applied Electrochemistry Time : 3 Hours

Max. Marks : 80

Instruction : Answer Q. No. 1 and any five of the remaining. 1. Answer any ten of the following :

(2×10=20)

a) Explain the role of stress relievers in electrodeposition and give examples. b) Calculate the throwing power of a bath, when the weights of Ag deposited are 0.596g and 0.821g on cathode 1 and 2 and the distances of the cathodes from the anode are 13 cm and 8 cm respectively. c) What are cathodic corrosion inhibitors ? Give the mode of their action. d) Explain the dry corrosion with suitable reactions. e) What is Pourbaix diagram ? Mention its significance. f) Draw E-I curve and give the meaning of the active and passive regions. g) What do you mean by the voltage of a battery ? Write an expression for it. h) Mention the electrolyte, electrodes and fuel used in molten carbonate Fuel cell. i) Write the ilkovic equation and explain the terms involved. j) Sketch and explain the shape of an ac polarography. k) Give the principle of spectroelectrochemical techniques. l) What is phase transfer electroorganic synthesis ? Give examples. 2. a) Give an account of the technological importance of Metal finishing. b) What are solar selective coatings ? Mention their types and applications. c) Write a note on i) porosity testing of a coat & ii) phosphating process. (3+4+5=12) P.T.O.

*PG724*

PG – 724

3. a) Define the terms ‘Capacity’ and ‘Energy storage density’ and mention their units. b) Discuss the construction and working of Zn-Air battery. c) Write a note on molten carbonate fuel cell with relevant reactions.

(3+5+4=12)

4. a) Discuss the concepts of ‘Local cell’ and ‘Wagner and Traud’ theory of corrosion. b) Explain the linear polarization method of corrosion rate determination. c) Give an account of sacrificial anode method of corrosion control.

(5+4+3=12)

5. a) Give the principle of cyclic voltammetry (CV) and explain the analytical criteria involved for any reversible process in CV. b) Derive the current-potential relation for the cathodic process at the DME. c) Write a note on anodic stripping voltammetry.

(5+4+3=12)

6. a) What are hydrodynamic electrodes ? Explain their mode of working with examples. b) Discuss on the principle of chronocoulometry and its application to study the surface active species. c) Calculate the energy density of a battery exhibiting the capacity of 5 Ah and discharging at 1.42 V. The weight of the battery is 1.5 kg. (4+5+3=12) 7. a) Give an account of ellipsometric technique for studying the passivating films. b) What is paired organic synthesis ? Explain the anodic synthesis of gluconic acid. c) Explain the effect of the following variable on the electroorganic synthesis i) electrode potential

ii) solvent and

iii) supporting electrolyte. (4+3+5=12)

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