Question

A container has gas mixture of 40% CO2 and 60% H2 with total pressure 10 Pa, if now O2 is added to it isothermally so that the final composition of the mixture becomes 20% CO2, 30% H2, and 50% O2, what is the partial pressure of O2 in the new composition?

(a) 5 Pa

(b) 10 Pa

(c) 20 Pa

(d) 35 Pa

The question was posed to me in homework.

The origin of the question is Ideal Gas Mixtures and Partial Pressure in chapter Recycle, Bypass, Purge, Ideal Gases and Real Gases of Basic Chemical Engineering

Answer 1

The correct choice is (b) 10 Pa

For explanation: Partial pressure of H2 = 0.6*10 = 6 Pa, => Partial pressure of O2 = 0.5*6/0.3 = 10 Pa.