Practice: A sample of 3.51 g argon and an unknown amount of oxygen are mixed in a container at room temperature. The partial pressure of argon was calculated as 71.0 torr and the partial pressure of oxygen as 188 torr. What is the mass of the oxygen within the container?
Partial Pressure (PGas) is the pressure exerted by an individual gas within a container.
Partial Pressure of Gases
Concept #1: Partial Pressure
In a container of unreacting gases, total pressure of the container is the sum of the partial pressures of each gas.
Example #1: A sample of neon gas exerts a pressure of 1.85 atm inside a cylinder. Some nitrogen gas is also present, at a pressure of 500 torr. What is the total pressure inside the cylinder?
Concept #2: Using moles to determine Partial Pressure
Example #2: If 12.0 g helium and 20.0 g oxygen are placed inside a 5.0 L cylinder at 30 ºC, what is the partial pressure of the helium gas?
Concept #3: Dalton’s Law
Example #3: 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.
Practice: A gas mixture contains 72.8% chlorine and 27.2% neon by mass. What is the partial pressure of neon in the mixture if the total pressure is recorded as 809 mmHg?
