M.Sc. (Semester III) (CBCS) Examination Nov/Dec-2018
Physical Chemistry
ELECTROCHEMISTRY
Time: 2½ Hours
Max. Marks: 70
Instructions: All questions are compulsory and carry equal marks. Figures to the right indicate full marks. Neat and labeled diagrams should be drawn wherever possible. Use of log table and calculator is allowed.
Q.1
Multiple choice questions:
14
Fuel cells are
Carbon cell
Hydrogen cell
Nuclear cell
Chromium cell
Common energy source in Indian villages is
Electricity
Coal
Sun
Wood and animal dung
Which type of chemical reaction is observed at cathode, in electrochemical corrosion?
Oxidation reaction
Peretectic reaction
Reduction reaction
None of the above
At high frequency the conductance of an electrolyte solution increases due to effect.
Debye
Falkenhagen
Wein
Debye-Falkenhegan
Name the secondary slow step in the theories of overvoltage.
Bubble formation
Productive formation
Integrated formation
All
Number of water molecule which participates in motion of ion relative to surrounding solvent is known as
solvation number
hydration number
zero number
crayon number
electrolyte is used in natural gas CO-Air fuel cell?
Molten Carbonates
MgO
BaSO4
H2O2

The Debye-Huckel Limiting law for a single ion is
ln fi ZiI ½
fi -AZi2
ln fi Zi2I ½
ln fi Zi2I
Chemical formula of Rust is,
Fe2O3
FeO
Fe3O4
Fe2O3.xH2O
10) Name of mechanism with which the abnormal conductance of hydrogen ion is explained.
Grotthus Drapper
Einstein
Grotthus
Stokes
11) Write the expression for the constant A in Debye Huckel Onsager equation.





12) Destruction of material due to its reaction with environment is called
Corrosion
Erosion
Collision
Devotion
13) Which equation is used to study electrode reactions?
Butler-Volmer
Stern Volmer
Pourbix
Gibbs
14) Potential generated when liquid was forced through porous material is
Kinetic potential
Sedimentation potential
Potential Barrier
Photosedimentation
Q.2
a)Answer the following (any four)
08
State the laws of electrolysis
How does fuel cell work?
What do you meant by polarization?
What is electrical double layer?
Explain electrokinetic phenomenon
b)Write notes on (Any two)
06
Entropy of salvation
Significance of fuel cell
Electrotyping technique
Q.3
a)Answer the following(Any two)
08
What is the effect of ions on the zeta potential?
Calculate zeta potential of a quartz particle moving with a velocity of 3x10-3 cm/sec in aqueous suspension under potential gradient of 10 V/cm. (Given 8.903 x 10-3 poise D 78.30 at 25 0C).
Comment on preventive measure of corrosion
b)Answer he following (Any one)
06
Explain in brief Streaming potential and sedimentation potential.
Discuss the Bjerrum's ion association theory in detail.
Q.4
a)Answer the following (Any two)
10
Explain Debye Huckel Limiting law and its applications to concentrated solutions.
Discuss the hydrogen oxygen fuel cell.
The efficiency of fuel cell is 92% and the standard enthalpy change of two electron reaction is 68 Kcal/mole. Calculate the equilibrium potential of the fuel cell.
b)Answer the following (Any one)
04
The activity coefficient of ion and ion pairs are 0.827 and 0.88 respectively for 0.5m KCl. If the fraction of association is 0.021. Calculate association constant.
Evaluate the Debye- Huckel constants A and B for nitrobenzene at
25 0C. 78.6 and 0.0183 poise)
Q.5
Answer the following (Any Two)
14
a)Explain Helmholtz-Perrin theory of electrical double layer.
b)State various kinds of electrokinetic effects and explain any one in detail.
c)Discuss the Debye-Falkenhagen and Wein effects in details and explain how they support formation of ionic atmosphere.