M.Sc. (Semester IV) (CBCS) Examination Nov/Dec-2018
Physical Chemistry
SURFACE CHEMISTRY
Time: 2½ Hours
Max. Marks: 70
Instructions: Attempt in all five questions. Section I is compulsory. Attempt any two questions from section II and section III. Answer to all questions (Section II and III) should be written in same answer book. All questions carry equal mark. Figures to right indicate full marks. Data: Boltzmann constant 1.38 x 10-23 J K-1 Planck's Constant 6.626x 10-34 JS
Section I
Q.1
Answer the following:
14
Point out the nature of variation of surface tension with concentration in positive adsorption.
What is Kraft temperature?
What is adhesion tension?
Define work of cohesion.
What is Langmuir Blodgett deposition?
Give the examples of lyophilic colloids.
Electrokinetic phenomenon depends upon
For adsorption of a gas on a solid, the plot of log x/m against log P is linear with slope equal to
Define Sintering?
What is microemulsion?
.x/m=kp1/n is an expression for
Differentiate the term Isotherm Isobar.
During hydrogenation of oils catalysts commonly used as
What is gel?
Section II
Q.2
Explain the factors affecting the CMC of surfactants?
07
What are surface active agents and classify them.
07
Q.3
What is surface film? Compare between gaseous film and condensed film.
07
Derive BET equation along with its postulates.
07
Q.4
Enlist the methods for the determination of surface area of a solid and explain any two of them.
07
How can Gibbs adsorption equation be converted into Langmuir equation?
07
Section III
Q.5
How will you prepare the lyophillic and lyophobic sol?
05
Derive Gibbs adsorption isotherm for adsorption from solution.
05
Explain the solubilization in detail with suitable examples.
04
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SLR-VF-173
Q.6
What is Kelvin equation? How will you see it to explain the hysteresis of adsorption?
05
Explain the tests used to identify the types of emulsion.
05
What is surface pressure? Compare isotherm of insoluble molecular films with P-V isotherms of ideal gas.
04
Q.7
Write a note on any Three of the following.
14
Capillary rise method of determining of contact angle.
Inversion emulsion
Hysteresis of contact angle
Microemulsion