Engineering Questions with Answers - Multiple Choice Questions

# Separation Processes MCQ’s- Rate-Based Methods for Packed Distillation Columns

1 - Question

What is λ= KV/L replaced by since the line for distillation is curved?
a) λ= mV/L
b) λ= MVL
c) λ= mL/V
d) λ= mV/K
Explanation: Because the equilibrium line for distillation is curved, λ= KV/L is replaces by λ=mV/L where m is dy/dx.

2 - Question

Which of the following is correct?
a) HETP = H OG λ(λ-1)
b) HETP = H OG λ/(λ-1)
c) HETP = H OG /λ(λ-1)
d) HETP = H OG -λ(λ- 1)
Explanation: HETP = H OG λ/(λ-1) is correct where λ= mV/L.

3 - Question

Which method uses McCabe-thiele diagram?
a) HETP method
b) HTU method
c) Ponchon-Savarit method
d) HODL method
Explanation: The HETP method used McCabe-thiele diagram first.

4 - Question

What happens when k x >k y ?
a) Resistance to mass transfer is mainly in vapor
b) Resistance to mass transfer is mainly in liquid phase
c) Resistance to mass transfer is mainly in solid phase
d) All the resistances are equal
Explanation: When k x >k y resistance to mass transfer is mainly in vapor.

5 - Question

What happens when k x <k y ?
a) Resistance to mass transfer is mainly in vapor
b) Resistance to mass transfer is mainly in liquid phase
c) Resistance to mass transfer is mainly in solid phase
d) All the resistances are equal
Explanation: When k x <k y resistance to mass transfer is mainly in liquid phase.

6 - Question

In which solution are the values of HTU and HETP constant?
a) Concentrated solution
b) True solution
c) Homogeneous solution
d) Dilute solution
Explanation: The values of HTU and HETP are constant in dilute solution.

7 - Question

What is HETP if H OG = 1.5ft and λ=01.5?
a) 1.23
b) 1.43
c) 1.65
d) 1.78
Explanation: Since HETP = H OG λ/(λ-1), HETP = 1.5ln(1.5/(1.5-1))= 1.65.

8 - Question

What is HETP if H OG = 2.5ft and λ=01.5?
a) 1.23
b) 1.78
c) 1.26
d) 2.74
Explanation: Since HETP = H OG λ/(λ-1), HETP = 2.5ln(1.5/(1.5-1))= 2.74.

9 - Question

What is HETP if H OG = 1.7ft and λ=1.9?
a) 1.27
b) 1.36
c) 1.89
d) 1.78
Explanation: Since HETP = H OG λ/(λ-1), HETP = 1.7ln(1.9/(1.9-1))= 1.27

10 - Question

What is HETP if H OG = 2.6ft and λ=01.6?
a) 1.56
b) 2.1
c) 2.55
d) 1.78