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.
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
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
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
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
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

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

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

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

Explanation: Since Permeance= N/(YxV.P-yP), Permeance= 10/(50-20)=1.33

10 - Question