Surface chemistry unit I test link (https://docs.google.com/forms/d/e/1FAIpQLSfTeOU6UPFhGAddsVI0XZH2HgyjZ0Hl-kzLHfF4O_1aDB836g/viewform?usp=sf_link )
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1. The phenomenon of concentrations of molecules of a gas or liquid at a solid surface is called
a) absorpt
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 critical temperature of the gas, the more readily will it be adsorbed
a) lower
b) higher
c) intermediate
d) none of these
Answer : b
6. The process of adsorption is
a) exothermic
b) endothermic
c) sometimes exothermic. sometimes endothermic
d) none of the above
Answer : a
7. Physical adsorption is a ________ process
a) reversible
b) irreversible
c) exothermic
d) none of these
Answer : a
8. Physical adsorption occurs rapidly at ________ temperature
a) low
b) high
c) absolute zero
d) none of these
Answer : a
9. Physical adsorption generally _______ with increasing temperature
a) decreases
b) increases
c) sometimes decreases, sometime increases
d) none of these
Answer : a
10. Chemisorption generally ______ with temperature
a) increases
b) decreases
c) remains the same
d) none of these
Answer : a
11. Multi-molecular layers are formed in
a) absorption
b) physical adsorption
c) chemisorption
d) reversible adsorption
Answer : c
12. 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
13. Freundlich isotherms is not applicable at
a) high pressure
b) low pressure
c) 273K
d) room temperature
Answer : a
14. 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
15. Which of the following is not an equation for Freundlich isotherm?
a) w/m= k x c 1/n
b) w/m = k x p 1/n
c) log w/m =log k + log p
d) log w/m = log k - 1/n lag p
Answer : d
16. In gas masks the poisonous gases are removed by the adsorbed by the process of
a) absorption
b) adsorption
c) catalysis
d) none of these
Answer : b
17. Froth flotation process for the concentration of sulphide are makes use of the process of
a) adsorption
b) heterogeneous catalysis
c) absorption
d) equilibrium
Answer : a
18. The water feed from all ions ( cations and anions ) is referred to as
a) heavy water
b) concentrated water
c) mineral water
d) demineralized water
Answer : d
19. Heat of adsorption is defined as the energy liberated when _____ of a gas is adsorbed on the solid surface
a) 1 molecule
b) 1 gram
c) 1 gm mole
d) 1 kg
Answer : c
20. In physical adsorption the gas molecules are held to the solid surface by
a) hydrogen bond
b) sigma bond
c) pi bond
d) van dal Wall's forces
Answer : d
21. The adsorption of hydrogen on charcoal is
a) physical adsorption
b) chemical adsorption
c) sorption
d) none of these
Answer : a
22. The process of desorption increases with _____ of pressure
a) decrease
b) increase
c) sometime increases, sometime decreases
d) none of these
Answer : a
23. 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
24. The heat of adsorption in physical adsorption lies in the range
a) 1-10 kJ mol-1
b) 10-400 kJ mol-1
c) 40-100 kJ mol-1
d) 40-400 kJ mol-1
Answer : a
25. In chromatographic analysis, the principle used is
a) absorption
b) adsorption
c) distribution
d) evaporation
Answer : b
26. Which of the following is not a characteristic of physical adsorption?
a) adsorption is reversible
b) multi molecular layer is formed
c) ^H is of the order 400 kJ
d) occurs rapidly at low temperature
Answer : c
27. 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
28. 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
29. Which out of the following is incorrect?
a) chemisorption is reversible in nature
b) physical adsorption is reversible in nature
c) ^H is small in physical adsorption
d) ^H is large in chemical adsorption
Answer : a
30. The efficiency of adsorbent increases with increase in
a) viscosity
b) surface tension
c) surface area
d) number of ions
Answer : c
31. The ion-exchange resins are the compounds with
a) high molecular masses
b) high surface tension
c) low viscosities
d) high surface area
Answer : a
32. Hard water is made soft by passing it through a column packed with high polymer resin. This process makes use of
a) cation-exchange
b) chromatographic analysis
c) adsorption of -vely charged ions
d) heterogeneous catalysis
Answer : a
33. 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
34.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
35. 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
36. The process represented by the equation
a) cation exchange
b) anion exchange
c) resin exchange
d) chromatographic analysis
Answer : a
37. An anion exchange process is represented by
d) none of these
Answer : b
38. In an adsorption process unimolecular layer is formed. It is
a) physical adsorption
b) chemical adsorption
c) ion- exchange
d) chromatographic analysis
Answer : b
39. Langmuir Isotherms holds at low pressure but fails at
a) low temperature
b) high pressure
c) intermediate pressure
d) none of these
Answer : b