Question

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

I had been asked this question in an internship interview.

Question is from Vapor-Liquid Equilibria in Binary Systems in section Two Phase Gas – Liquid Systems, Phase Rule and Vapor-Liquid Equilibria of Basic Chemical Engineering

Answer 1

The correct choice is (a) 0.4

For explanation I would say: Fraction of gas = 2/5 = 0.4.