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?

**Partial Pressure (P _{Gas})** is the pressure exerted by an individual gas within a container.

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: Fractional Composition to Partial Pressure

Example #3: A cylinder of a gas mixture used for calibration of blood gas analyzers in medical laboratories contains 5.0% CO_{2}, 12.0% O_{2}, and the remainder N_{2} at a total pressure of 146 atm. What is the partial pressure of each component of this gas?

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?

Practice: The partial pressure of N_{2} in the air is 593 mmHg at 1 atm. What is the partial pressure of N_{2} in a bubble of air a scuba diver breathes when he is 66 ft below the surface of the water where the pressure is 3.00 atm?