Question

What is the fraction of a gas in a system at partial pressure 1 atm, if the 0.2 fraction of the same gas is at partial pressure 4 atm and 0.4 fraction at partial pressure 8 atm (Use Freundlich Isotherm)?

(a) 0.1

(b) 0.2

(c) 0.4

(d) 0.5

This question was posed to me during an interview.

The query is from Liquids and Gases in Equilibrium with Solids topic in section Liquids and Gases in Equilibrium with Solids and Energy: Terminology, Concepts, and Units of Basic Chemical Engineering

Answer 1

Right choice is (d) 0.5

The explanation: y1/y2 = (p1/p2)^n, => 0.2/0.4 = (4/8)^n => n = 1, => 0.2 = k*4^1 = k = 0.2/4, => y = 0.2/4*1 = 0.05.