250+ TOP MCQs on Vapor-Liquid Equilibria in Binary Systems and Answers

Chemical Engineering Multiple Choice Questions & Answers on “Vapor-Liquid Equilibria in Binary Systems”.

1. What is the partial pressure of a 40% gas in a system with vapor pressure 1 mm Hg?
a) 0.2 mm Hg
b) 0.4 mm Hg
c) 0.6 mm Hg
d) 0.8 mm Hg

Answer: b
Clarification: p = 0.4*1 = 0.4 mm Hg.

2. What is the vapor pressure of 50% gas in a system with partial pressure 2 mm Hg?
a) 1 mm Hg
b) 2 mm Hg
c) 4 mm Hg
d) 8 mm Hg

Answer: c
Clarification: P = 2/0.5 = 4 mm Hg.

3. What is the fraction of gas in a system with partial pressure 2 mm Hg and vapor pressure 5 mm Hg?
a) 0.4
b) 0.5
c) 0.6
d) 0.8

Answer: a
Clarification: Fraction of gas = 2/5 = 0.4.

4. What is the partial pressure of 20% gas in a system with vapor pressure 10 mm Hg?
a) 2 mm Hg
b) 10 mm Hg
c) 50 mm Hg
d) 100 mm Hg

Answer: a
Clarification: Partial pressure = 0.2*10 = 2 mm Hg.

5. What is the vapor pressure of 40% gas in a system with partial pressure 20 mm Hg?
a) 5 mm Hg
b) 10 mm Hg
c) 20 mm Hg
d) 50 mm Hg

Answer: d
Clarification: Vapor pressure = 20/0.4 = 50 mm Hg.

6. According to Henry’s Law, what is the fraction of a gas with partial pressure p and Henry’s constant H?
a) p*H
b) p/H
c) p + H
d) p – H

Answer: b
Clarification: According to Henry’s Law, p = H*x, => x = p/H.

7. What is the partial pressure of a 10% gas in a system, if H = 2 mm Hg?
a) 0.1 mm Hg
b) 0.2 mm Hg
c) 0.3 mm Hg
d) 0.4 mm Hg

Answer: b
Clarification: p = 0.1*2 = 0.2 mm Hg.

8. What is the fraction of a gas in a system with partial pressure 10 mm Hg, H = 25 mm Hg?
a) 0.1
b) 0.2
c) 0.3
d) 0.4

Answer: d
Clarification: Fraction of a gas = 10/25 = 0.4.

9. A 40% gas in a system has partial pressure 4 atm, what is Henry’s constant?
a) 1.6 atm
b) 4 atm
c) 10 atm
d) 16 atm

Answer: c
Clarification: H = 4/0.4 = 10 atm.

10. What is the partial pressure of a 70% gas in a system, if H = 5 mm Hg?
a) 3.5 mm Hg
b) 7 mm Hg
c) 14 mm Hg
d) 35 mm Hg

Answer: a
Clarification: Partial pressure = 0.7*5 = 3.5 mm Hg.

11. What is the K value of a gas with partial pressure 10 atm and the total pressure of the system is 50 atm?
a) 0.1
b) 0.2
c) 100
d) 500

Answer: b
Clarification: K = 10/50 = 0.2.

12. What is the K value of a gas with partial pressure 50 Pa and the total pressure of the system is 1 mm Hg?
a) 0.37
b) 0.45
c) 0.79
d) 0.91

Answer: a
Clarification: K = 50/133.3 = 0.37.

13. What is the total pressure of a system having 40% O₂ with 5 atm partial pressure and 60% N₂ with 10 atm partial pressure?
a) 2 atm
b) 6 atm
c) 8 atm
d) 10 atm

Answer: c
Clarification: P = 0.4*5 + 0.6*10 = 8 atm.

14. What is the total pressure of a system having 25% CO₂ with 4 atm partial pressure and 30% O₂ with 10 atm partial pressure, and 45% SO₂ with partial pressure 20 atm?
a) 9 atm
b) 13 atm
c) 17 atm
d) 19 atm

Answer: b
Clarification: P = 0.25*4 + 0.3*10 + 0.45*20 = 1 + 3 + 9 = 13 atm.

15. What is the total pressure of a system having 50% H₂CO₃ with 6 atm partial pressure and 50% O₂ with 12 atm partial pressure?
a) 3 atm
b) 6 atm
c) 9 atm
d) 12 atm

Answer: c
Clarification: P = 0.5*6 + 0.5*12 = 9 atm.