Engineering Questions with Answers - Multiple Choice Questions
Separation Processes MCQ’s – Pervaporation
1 - Question
Pervaporation method involves
a) Removal of ions
b) Production of potable water
c) Purification of aqueous streams
d) Separation and concentration of liquid mixture.
View Answer
Explanation: Pervaporation is process of separation and concentration of liquid mixture
2 - Question
When is the pervaporation preferred?
a) When feed solution is dilute in main permeant
b) When feed solution is rich in main permeant
c) When feed solution is dilute in retentate
d) When feed solution is rich in retentate
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Explanation: Pervaporation is preferred when the feed solution is dilute in main permeant. If the solution is rich in permeant then more number of membrane stages may be required.
3 - Question
Which type of membrane is required for water permeation?
a) Hydrophobic
b) Hydrophilic
c) Semipermeable
d) Permeable
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Explanation: When water is to be permeated, hydrophilic membrane is required making the selection of membranes an important factor.
4 - Question
What factor is unaccountable in gas permeation?
a) Temperature
b) Polymer
c) Permeant
d) Concentration of permeants
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Explanation: The concentration of permeants is not dependent in gas permeation.
5 - Question
What are the permeant vales, if permeant flux(N)= 10 For feed side liquid: Y=0.5, x= 0.5 Vapor pressure = 100 Mole fraction of permeant vapor y= 0.25 Total permeant pressure P= 80 a) 2 b) 4 c) 5 d) 7
View Answer
Explanation: Since Permeance= N/(YxV.P-yP), Permeance= 10/(25-20)=2.
6 - Question
What are the permeant vales, if permeant flux(N)= 10
For feed side liquid: Y=0.6, x= 0.5
Vapor pressure = 100
Mole fraction of permeant vapor y= 0.25
Total permeant pressure P= 80
a) 2
b) 4
c) 5
d) 1
View Answer
Explanation: Since Permeance= N/(YxV.P-yP), Permeance= 10/(30-20)=1.
7 - Question
What are the permeant vales, if permeant flux(N)= 10
For feed side liquid: Y=10, x= 0.4
Vapor pressure = 100
Mole fraction of permeant vapor y= 0.5
Total permeant pressure P= 80
a) 20
b) 40
c) 50
d) 0.03
View Answer
Explanation: Since Permeance= N/(YxV.P-yP), Permeance= 10/(400-40)=0.03.
8 - Question
What are the permeant vales, if permeant flux(N)= 10
For feed side liquid: Y=0.5, x= 0.5
Vapor pressure = 100
Mole fraction of permeant vapor y= 0.25
Total permeant pressure P= 60
a) 2
b) 41
c) 1
d) 7
View Answer
Explanation: Since Permeance= N/(YxV.P-yP), Permeance= 10/(25-15)=1.
9 - Question
What are the permeant vales, if permeant flux(N)= 10
For feed side liquid: Y=0.5, x= 0.5
Vapor pressure = 200
Mole fraction of permeant vapor y= 0.25
Total permeant pressure P= 80
a) 1.33
b) 2.55
c) 5.44
d) 7
View Answer
Explanation: Since Permeance= N/(YxV.P-yP), Permeance= 10/(50-20)=1.33
10 - Question
Incorrect statement about pervaporation is
a) Low cost
b) Independent of vapour/liquid equilibrium
c) Suitable for heat sensible product
d) Require high temperature and high pressure.
View Answer
Explanation: Pervaporation does not require high temperature and high pressure