Mass Transfer Multiple Choice Questions on “Distillation Types”.
1. In Azeotropic distillation __________ remains low.
a) Heat
b) Volatility
c) Relative volatility
d) None of the mentioned
Answer: c
Clarification: Same vapour pressure of the mixture has nearby volatility.
2. Find the distillation preferred for the binary mixture having component A and B with vapour pressure 360mmHg and 355mmHg.
a) Multi-component distillation
b) Reactive distillation
c) Azeotropic distillation
d) All of the mentioned
Answer: c
Clarification: Relative volatility = Vapour pressure of A/ Vapour pressure of B
= 360/355 = 1.014 ( Azeotropic composition).
3. The term entrainer used in
a) Multi-component distillation
b) Reactive distillation
c) Azeotropic distillation
d) None of the mentioned
Answer: c
Clarification: Entrainer increases the relative volatility.
4. By adding Entrainer the __________ azeotropes forms.
a) Low boiling
b) High boiling
c) No
d) None of the mentioned
Answer: a
Clarification: Since when we add entrainer the relative volatility increases by formation of low boiling azeotropes.
5. The use of solvent for increasing the relative volatility is for
a) Multi-component distillation
b) Reactive distillation
c) Azeotropic distillation
d) Extractive distillation
Answer: d
Clarification: Generally, solvent is used for extraction. As it helps to alter the relative volatility it is used in extractive distillation.
6. In the distillate use of heat is to separate the distillate from the entrainer.
a) True
b) False
Answer: a
Clarification: See, in Azeotropic distillation the overhead products will be composed of entrainer added. In order to pure product heat is given to the distillate product.
7. Find the Azeotropic mixture.
a) Air-water
b) Acetic acid- water
c) Acetic acid- alcohol
d) Air-alcohol
Answer: b
Clarification: Acetic acid- water mixture has the nearby same boiling point.
8. If the feed mixture has the same vapour and liquid compositions at equilibrium then the distillation is normal.
a) True
b) False
Answer: b
Clarification: If the liquid and the vapour compositions are same the relative volatility becomes 1 and there must be an azeotropes formation.
9. Will it possible to separate the mixture having relative volatility value 2 with azeotropic distillation.
a) True
b) False
Answer: b
Clarification: Because if the relative volatility is 2 there will be a large difference in vapour pressure so there won’t be any Azeotropic formation.
10. By adding entrainer or solvent one of the component’s _________ gets reduced.
a) Boiling point
b) Bubble point
c) Dew point
d) All of the mentioned
Answer: a
Clarification: By adding entrainer or solvent the relative volatility increased due to a decrease in the boiling point of one component.