Gases: Partial Pressure and Mole Fraction

Question

A mixture of carbon dioxide and hydrogen gases contains carbon dioxide at a partial pressure of 319 mm Hg and hydrogen at a partial pressure of 646 mm Hg. What is the mole fraction of each gas in the mixture?

X_CO2 = 

X_H2 = 

Answer 1

Dalton's Law of Partial Pressure:

P_total = P_CO2 + P_H2

Total pressure = 319 mm Hg + 646 mm Hg = 965 mm Hg

mol fraction CO2 = 319 / 965 = 0.330

mol fraction H2 = 646 / 965 = 0.67