Master of Science II (Physical Chemistry)
Examination: Oct Nov 2016 Semester IV (Old CGPA)
SLR No. Day
Date Time Subject Name Paper
No. Seat No.
SLR SD
256
Thursday
24/11/2016
02:30 P.M
To
05:00 P.M
Surface Chemistry
C
XVI
Instructions: Attempt in all five questions.
Section I is compulsory.
Attempt any two questions from Section II and any two
from Section III
Answer to all questions (Section II and III) should be
written in the one answer book.
All questions carry equal marks.
Figures to the right indicate full marks.
Total Marks:70
SECTION I
Q.1 Solve the following: 14
Define the term Tamann temperature.
Which of the followings is the cationic surfactant?
Octadecyl ammonium chloride Sodium palmitate
Sodium stearate None of these
State whether the accessories used in the Langmuir surface pressure
balance are hydrophobic or hydrophilic in nature.
What is adsorption isoster?
Define the term heat of wetting.
Define specific surface free energy of solids.
Predict emulsion type if it feels creamy.
Point out the effect of temperature on the critical micelle concentration.
How will you relate contact angle with the spreading of liquid on the
surface of solid?
Mention the use of mercury porosometer.
"Mercury on flat solid surface takes spherical shape", why?
According to the Langmuir adsorption isotherm, the amount of gas
adsorbed at very high pressure
reaches a constant limiting value.
goes on decreasing with pressure.
goes on increasing with pressure.
increases first and then decreases.
How will you relate critical micelle concentration and length of
hydrophobic part of the surfactant molecule?
Which of the following kinds of catalysis can be explained by the
adsorption theory?
homogeneous catalysis heterogeneous catalysis
enzyme catalysis acid -base catalysis
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SECTION II
Q.2 Give a detailed account on volumetric method of gas adsorption. 07
What are emulsifiers? Discuss theories of emulsification. 07
Q.3 Give a brief comment on the adsorption isotherms and the factors affecting
adsorption.
07
Mention the various methods that can be used to determine the specific
surface area of an adsorbent and describe any one method in detail.
07
Q.4 Derive Gibb's Adsorption equation with usual notation for dilute solution.
For a 2x10-1M solution of butyric acid in water at 205°C the rate at which
the surface tension varies with concentration
Determine the surface excess concentration.
07
Derive Langmuir adsorption isotherm and explain its advantages and
disadvantages.
07
SECTION III
Q.5 "The monomolecular surface films of standard higher fatty acids behave
like three dimensional gases", Justify the statement.
05
Describe maximum bubble pressure method of determination of the surface
tension of liquids.
05
What are the solid lubricants? Discuss the mechanisms hydrodynamic and
boundary lubrication.
04
Q.6 What is sintering? Discuss mechanism of this process. 05
Derive Kelvin equation which relates vapour pressure of water inside and
outside the droplet.
05
State and explain Trube's rule. 04
Q.7 Write a note on any Four of the following: 14
Detergency
Application of micelle in solubilization water insoluble organic material.
Selective wetting
Langmuir-Adam surface pressure balance