Dalton's Law

Dalton's Law

States that the total pressure of a gas mixture is equal to the sum of the partial pressures of each individual gas.

Partial Pressure

The pressure exerted by an individual gas in a mixture of gases.

Mole Fraction

A measure of the number of moles of a substance compared to the total moles of matter present.

Total Pressure

The overall pressure exerted in a gas mixture, calculated as the sum of the partial pressures.

Atmospheric Pressure

The pressure exerted by the weight of the atmosphere, typically measured at sea level as one atmosphere.

Ideal Gases

Gases that follow the ideal gas law, where the identities of the gases do not affect the mixture's overall properties.

Calculation of Partial Pressure

Multiply the mole fraction of a gas by the total pressure to find the partial pressure.

Example of Dalton's Law

In Earth's atmosphere, the partial pressures of nitrogen, oxygen, and argon sum to equal the atmospheric pressure.

Interaction of Gases

As long as gases do not react, they can be treated independently when calculating pressures within mixtures.