B.Sc. Second year Undergraduate degree course (CBCS Pattern)
Semester Third
Physical Chemistry (CHE-312) B.Sc. Notes
Chapter – Surface Chemistry
Multiple
Choice Questions
1.
The phenomenon of concentrations of molecules of a gas or liquid at a solid
surface is called
(a)
Absorption
(b)
Adsorption
(c)
Catalysis
(d)
None of these
Answer.
(b)
2.
Adsorbate is that substance
(a)
Which concentrates on the surface
(b)
Where adsorption takes place
(c)
Which evaporates from the surface of metals
(d)
None of these
Answer.
(a)
3.
The adsorption of gases on metal surfaces is called
(a)
Catalysis
(b)
Occlusion
(c)
Adsorption
(d)
Absorption
Answer.
(b)
4.
Increase in _______ of the adsorbent increases the total amount of the gas
adsorbed
(a)
Density
(b)
Volume
(c)
Surface area
(d)
Surface tension
Answer.
(c)
5.
The process of adsorption is
(a)
Exothermic
(b)
Endothermic
(c)
Sometimes exothermic, sometimes endothermic
(d)
None of the above
Answer.
(a)
6.
Physical adsorption is a _______ process
(a)
Reversible
(b)
Irreversible
(c)
Exothermic
(d)
None of these
Answer.
(a)
7.
Physical adsorption occurs rapidly at _______ temperature
(a)
Low
(b)
High
(c)
Absolute zero
(d)
None of these
Answer.
(a)
8.
Physical adsorption generally _______ with increasing temperature
(a)
Decreases
(b)
Increases
(c)
Sometimes decreases, sometime increases
(d)
None of these
Answer.
(a)
9.
Chemisorption generally _______ with temperature
(a)
Increases
(b)
Decreases
(c)
Remains the same
(d)
None of these
Answer.
(a)
10.
Multi-molecular layers are formed in
(a)
Absorption
(b)
Physical adsorption
(c)
Chemisorption
(d)
Reversible adsorption
Answer.
(c)
11.
The relationship between equilibrium pressure of a gas and its amount adsorbed
on the solid adsorbent at constant temperature is called
(a)
Chemisorption
(b)
Adsorption isobars
(c)
Adsorption isotherms
(d)
None of these
Answer.
(c)
12.
Freundlich isotherms is not applicable at
(a)
High pressure
(b)
Low pressure
(c)
2730 K
(d)
Room temperature
Answer.
(a)
13.
At low pressures, the amount of the gas adsorbed is _______ proportional to the
pressure
(a)
Directly
(b)
Inversely
(c)
Sometimes directly, sometimes inversely
(d)
none of these
Answer.
(a)
14.Which
of the following is not an equation for Freundlich isotherm?
Answer. (d)
15.In
gas masks the poisonous gases are removed by the adsorbent by the process of
(a)
Absorption
(b)
Adsorption
(c)
Catalysis
(d)
None of these
Answer.
(b)
16.In
physical adsorption the gas molecules are held to the solid surface by
(a)
Hydrogen bond
(b)
Sigma bond
(c)
pi bond
(d)
van der Waal’s forces
Answer.
(d)
17.
The adsorption of hydrogen on charcoal is
(a)
Physical adsorption
(b)
Chemical adsorption
(c)
Sorption
(d)
None of these
Answer.
(a)
18.
The process of desorption increases with _______ of pressure
(a)
Decrease
(b)
Increase
(c)
Sometime increases, sometimes decreases
(d)
None of these
Answer.
(a)
19.
Adsorption takes place with
(a)
Decrease in enthalpy of the system
(b)
Increase in enthalpy of the system
(c)
No change in enthalpy of the system
(d)
None of these
Answer.
(a)
20.In
gas masks, the poisonous gases are adsorbed by activated charcoal. The
activated charcoal acts as
(a)
adsorbate
(b)
Adsorbent
(c)
Catalysis
(d)
adsorption agent
Answer.
(b)
21.
Which is incorrect statement?
(a)
Physical adsorption is irreversible in water
(b)
Physical adsorption involves multi-molecular layers
(c)
The energy evolved is small
(d)
Physical adsorption is caused by van der Waal’s forces
Answer.
(a)
22.
Which out of the following is incorrect?
(a)
Chemisorption is reversible in nature
(b)
Physical adsorption is reversible in nature
(c)
ΔH is small in physical adsorption
(d)
ΔH is large in chemical adsorption
Answer.
(a)
23.
The efficiency of adsorbent increases with increase in
(a)
Viscosity
(b)
Surface tension
(c)
Surface area
(d)
Number of ions
Answer.
(c)
24.
Which of the following is not an application of adsorption?
(a)
Gas masks
(b)
Heterogeneous catalysis
(c)
Froth flotation process
(d)
Softening of water by boiling
Answer.
(d)
25.
Langmuir while deriving adsorption isotherms did not make the following
assumptions
(a)
The layer of the gas adsorbed on the solid surface is one-molecule thick
(b)
The absorbed layer is uniform
(c)
There is no attraction between the adjacent molecules
(d)
The attraction between the adsorbent molecules is extremely large
Answer.
(d)
26.
Which of the following is incorrect?
(a)
Chemisorption is caused by bond formation
(b)
Chemisorption is specific in nature
(c)
Chemisorption is reversible
(d)
Chemisorption increases with increase in temperature
Answer.
(c)
27.
Langmuir Isotherms holds at low pressure but fails at
(a)
Low temperature
(b)
High pressure
(c)
Intermediate pressure
(d)
None of these
Answer.
(b)
Surface Chemistry: Introduction,some basic terms, adsorption materials, factors affecting adsorption
Surface Chemistry:characteristics of adsorption, types of adsorption, classification of adsorption isotherms, Langmuir adsorption isotherm
Surface Chemistry:Freundlich's adsorption isotherm, BET theory , application of adsorption
Surface Chemistry: Multiple Choice questions
