Gas Vocab /Formulas

Pressure of a gas

The force the gas exerts on the walls of its container.

Standard units of pressure

1 atmosphere (atm)

101.3 kilopascals (kPa)

760 millimeters mercury (mmHg)

760 torr

Pressure conversions

Multiply by the standard pressure of what you want, and divide by the standard pressure of what you have.

Example of a pressure conversion

2.5 atm x 101.3 kPa/1 atm = 253.25 kPa

Volume of a gas

Measured in liters or millimeters.

1000 ml=1L

Temperature of a gas

A measurement of the kinetic energy of the molecules. Measured by Celsius and Kelvin.

What to do when converting temperature

Convert Celsius to Kelvin—> Add 273

Convert Kelvin to Celsius—> Subtract 273

Pressure vs Volume

As volume decreases, pressure of the gas increases.

Boyle’s Law

P1 V1 = P2 V2

Volume vs temperature

As temperature decreases, volume decreases. As temperature increases, volume increases.

Charles Law

Jacques Charles described how gases tend to expand when heated and was the first person to launch a hydrogen filled balloon. (Temperature must be in Kelvin)

Charles’ Law Formula

V1 /T1=V2/T2

Pressure vs Temperature

As temperature increases, pressure increases. As temperature decreases, pressure decreases.

Gay-Lussac’s Law

States that if the mass and volume of a gas are held constant then gas pressure increases linearly as the temperature rises.

Gay Lussac’s Law Formula

P1/T1 =P2/T2

Combined Gas Law

P1 V1/T1 =P2 V2/T2

Ideal Gases

Gases that follow closely to the kinetic molecular theory. Gases behave most ideal at high temperatures and low pressures.

Ideal Gas Law

PV= nRT

Kinetic Molecular Theory

Gas particles move very fast in straight lines until they collide with each other or the container.

Robert Boyle

Showed how pressure and volume are always inversely proportional.

Relationship between volume and temperature

Directly proportional.

Ideal Gas constant

8.314

Ideal Gas Constant (when trying to find pressure in atm)

0.08206