Dalton's Law, Mole Fraction & Partial Pressure

According to Dalton’s Law, the total pressure inside a container is obtained by adding all the partial pressures of each non-reacting gas. 

Examining Dalton's Law

Mole Fraction & Partial Pressure

Concept: Understanding mole fraction and partial pressure


The partial pressure of a gas is based on the moles of that gas. The relationship of the different moles of gases helps us determine the mole fraction of each gas. 

Example: A container has 16.7 g O2, 8.1 g H2 and 35.2 g N2 and contains a total pressure of 0.83 atm. Calculate the mole fraction of O2 and its partial pressure. 


Problem: A gas mixture with a total pressure of 812 mmHg contains the following gases at with their partial pressures: Cl= 210 mmHg, H2 = 180 mmHg, CO2 = 215 mmHg. If argon gas is also present calculate its mole fraction.