Saurastra University 2006 M.Sc Computer Science Physical Chemistry : - X (Electrochemistry) - Question Paper

M. Sc. (Part - II) exam
April / May – 2006
Physical Chemistry : Paper - X
(Electrochemistry)
Time : three Hours] [Total Marks : 100
Instructions : (1) All ques. carry equal marks.
(2) Attempt 5 ques. in all.
(3) Q one is compulsory.
(4) Attempt any 4 from Q No two to 7.
1 ans the subsequent : (any four)
(a) Define: Liquid junction potential, Polarography, Degree of
dissociation, Amphoteric electrolyte, Over voltage.
(b) State the Faraday’s legal regulations of electrolysis.
(c) discuss the Nernst theory of solution pressure.
(d) explain the relation ranging from degree of dissociation and ionic
mobilities.
(e) discuss abnormal transference number.
(f) elaborate the various kinds of polarographic techniques?
Draw a hypothetical DC polarogram and tag its different
regions.
(g) discuss the factors affecting overvoltage.
(h) explain the effect of temperature on ionic product of water.
2 (a) define the applications of Nernst formula in detail.
(b) discuss the mechanism of electrolytic conductance in detail.
3 (a) Discus the determination of dissociation constant of a weak
acid by conductance method.
(b) compute the molar conductance of NH
4
OH at infinite
dilution from the subsequent data:
 
NaOH = 247.8 x 10–4 m2 mho mole-1
 
NHu Cl = 149.7 x 10
-4
m2 mho mole-1
 
NaCl = 126.45 x 10-4 m2 mho mole-1
(c) discuss the effect of dilution on various kinds of conductances.
4 (a) define pulse polarography.
(b) subsequent ac polarographic data on Cd
2+
are given:
[Cd2+] (mM) 0.50 1.00 2.00 3.00 3.75 Unknown
Peak
Current ( A) 1.20 2.42 4.86 7.28 9.11 4.73
Determine the concentration of unknown Cd
2+
solution.
(c) explain polarographic maxima and its elimination.
5 (a) define the effect of solvent on dissociation constants.
(b) A nitrate-selective electrode and a reference electrode
were dipped in a solution of nitrate with an activity of
1 x 10-3 M and the potential of nitrate selective electrode
was -122.4mV. The identical electrode pair was dipped into a
solution containing both nitrate and chloride at an activity
of 1x10-3 every. The potential of nitrate selective electrode in
that solution was -124.8 mV. The temperature of solution
was 25oC. compute the selectivity coefficient of nitrate
selective electrode for chloride.
(c) provide an account of Hydrogen overvoltage.
6 ans the subsequent :
(a) explain ionic diffusion as slow process in overvoltage.
(b) What is dipolar ions? provide evidences for their existence.
(c) discuss the mechanism of Grotthus conductance.
7 Write notes on : (any three)
(a) Anodic and cathodic potentials
(b) Calorimetric determination of dissociation constant
(c) Moving boundary method
(d) Electrochemical series
(e) Application of conductance measurements.
______________
ST-2760] two [ 100 ]

Earning:   Approval pending.