Mixtures of Gases: Dalton's Law of Partial Pressures and Mole Fractions

The pressure of a pure gas is the sum of molecular collisions between its particles and surrounding surfaces. A gas sample with fewer particles in a given volume exerts a lower pressure than a sample with more particles in the same volume.

But what is the pressure of a mixture of different gases? For a multicomponent gas mixture, the pressure is the sum of collisions from all gas molecules.

It is assumed that each component in the mixture exerts its own pressure that is independent of the other gases present. The pressure from any individual component is called its partial pressure.

The total pressure of the ideal gas mixture equals the sum of the partial pressures of its components. This observation is Dalton's law of partial pressures.

By applying the ideal gas law, the partial pressures of the individual gas components are substituted with measurable variables.

Since the gases in the mixture occupy the same volume and are at the same temperature, the equation can be simplified.

The sum of the moles of the individual components equals the total number of moles of all gas components, n_total. Therefore, the total pressure of the gas mixture is equal to n_total multiplied by the cons