Chemical Engineering

Vapor-Liquid Equilibria in Binary Systems

Question 1
Marks : +2 | -2
Pass Ratio : 100%
What is the vapor pressure of 40% gas in a system with partial pressure 20 mm Hg?
5 mm Hg
10 mm Hg
20 mm Hg
50 mm Hg
Explanation:
Vapor pressure = 20/0.4 = 50 mm Hg.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
What is the vapor pressure of 50% gas in a system with partial pressure 2 mm Hg?
1 mm Hg
2 mm Hg
4 mm Hg
8 mm Hg
Explanation:
P = 2/0.5 = 4 mm Hg.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
What is the partial pressure of a 40% gas in a system with vapor pressure 1 mm Hg?
0.2 mm Hg
0.4 mm Hg
0.6 mm Hg
0.8 mm Hg
Explanation:
p = 0.4*1 = 0.4 mm Hg.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
What is the partial pressure of 20% gas in a system with vapor pressure 10 mm Hg?
2 mm Hg
10 mm Hg
50 mm Hg
100 mm Hg
Explanation:
Partial pressure = 0.2*10 = 2 mm Hg.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
What is the partial pressure of a 70% gas in a system, if H = 5 mm Hg?
3.5 mm Hg
7 mm Hg
14 mm Hg
35 mm Hg
Explanation:
Partial pressure = 0.7*5 = 3.5 mm Hg.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
What is the partial pressure of a 10% gas in a system, if H = 2 mm Hg?
0.1 mm Hg
0.2 mm Hg
0.3 mm Hg
0.4 mm Hg
Explanation:
p = 0.1*2 = 0.2 mm Hg.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
A 40% gas in a system has partial pressure 4 atm, what is Henry’s constant?
1.6 atm
4 atm
10 atm
16 atm
Explanation:
H = 4/0.4 = 10 atm.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
What is the fraction of gas in a system with partial pressure 2 mm Hg and vapor pressure 5 mm Hg?
0.4
0.5
0.6
0.8
Explanation:
Fraction of gas = 2/5 = 0.4.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
According to Henry’s Law, what is the fraction of a gas with partial pressure p and Henry’s constant H?
p*H
p/H
p + H
p – H
Explanation:
According to Henry’s Law, p = H*x, => x = p/H.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
What is the fraction of a gas in a system with partial pressure 10 mm Hg, H = 25 mm Hg?
0.1
0.2
0.3
0.4
Explanation:
Fraction of a gas = 10/25 = 0.4.