Engineering Questions with Answers - Multiple Choice Questions

# Separation Processes MCQ’s – Differential Distillation

1 - Question

In differential distillation, there is no ____________
a) Distillate
b) Reaction
c) Reflux
d) Vapors
Explanation: In differential distillation, there is no reflux.

2 - Question

What is the condition for Yd and xd for toatal condensation?
a) Yd greater than xd
b) Yd smaller than xd
c) Yd smaller than or equal to xd
d) Yd equal to xd
Explanation: For total condensation Yd=Xd.

3 - Question

What is the mole fraction in instantaneous distillate if:
Moles of liquid in residue at start W0= 1000
Moles of liquid in residue at end W= 500
Mole fraction in liquid at start X0 = 0.6
Mole fraction in liquid at end X= 0.5
a) 0.2
b) 0.3
c) 0.4
d) 0.5

Explanation: XD = W0X0 –WX/W0-X, hence Xd= 0.2.

4 - Question

What is the mole fraction in instantaneous distillate if:
Moles of liquid in residue at start W0= 800
Moles of liquid in residue at end W= 500
Mole fraction in liquid at start X0 = 0.5
Mole fraction in liquid at end X= 0.1
a) 0.2
b) 0.3
c) 1
d) 0.5

Explanation: XD = W0X0 –WX/W0-X, hence Xd= 1.

5 - Question

What is the mole fraction in instantaneous distillate if:
Moles of liquid in residue at start W0= 2000
Moles of liquid in residue at end W= 500
Mole fraction in liquid at start X0 = 0.3
Mole fraction in liquid at end X= 0.4
a) 0.23
b) 0.34
c) 0.27
d) 0.56

Explanation: XD = W0X0 –WX/W0-X, hence Xd= 0.27.

6 - Question

What is the mole fraction in instantaneous distillate if:
Moles of liquid in residue at start W0= 1000
Moles of liquid in residue at end W= 500
Mole fraction in liquid at start X0 = 0.5
Mole fraction in liquid at end X= 0.2
a) 0.2
b) 0.66
c) 0.4
d) 0.8

Explanation: XD = W0X0 –WX/W0-X, hence Xd= 0.8.

7 - Question

What is the mole fraction in instantaneous distillate if:
Moles of liquid in residue at start W0= 1000
Moles of liquid in residue at end W= 500
Mole fraction in liquid at start X0 = 0.25
Mole fraction in liquid at end X= 0.1
a) 0.2
b) 0.3
c) 0.4
d) 0.5

Explanation: XD = W0X0 –WX/W0-X, hence Xd= 0.4.

8 - Question

What is the mole fraction in instantaneous distillate if:
Moles of liquid in residue at start W0= 1000
Moles of liquid in residue at end W= 600
Mole fraction in liquid at start X0 = 0.6
Mole fraction in liquid at end X= 0.5
a) 0.2
b) 0.67
c) 0.44
d) 0.75

Explanation: XD = W0X0 –WX/W0-X, hence Xd= 0.75.

9 - Question

What is the mole fraction in instantaneous distillate if:
Moles of liquid in residue at start W0= 1000
Moles of liquid in residue at end W= 500
Mole fraction in liquid at start X0 = 0.7
Mole fraction in liquid at end X= 0.4
a) 0.2
b) 1
c) 0.4
d) 0.5

Explanation: XD = W0X0 –WX/W0-X, hence Xd= 1.

10 - Question

. What is the mole fraction in instantaneous distillate if:
Moles of liquid in residue at start W0= 1000
Moles of liquid in residue at end W= 300
Mole fraction in liquid at start X0 = 0.6
Mole fraction in liquid at end X= 0.5
a) 0.26
b) 0.61
c) 0.64
d) 0.59