;Grahams law: This law states that the rate at which gas molecules diffuse is inversely proportional to the square root of the gas density at a constant temperature. Combined with Avogadros law (i.e. since equal volumes have an equal number of molecules) this is the same as being inversely proportional to the root of the molecular weight.
;Daltons law of partial pressures: This law states that the pressure of a mixture of gases simply is the sum of the partial pressures of the individual components. Daltons law is as follows:
:and all component gases and the mixture are at the same temperature and volume
:where P is the total pressure of the gas mixture
:P is the partial pressure or pressure of the component gas at the given volume and temperature.
;Amagats law of partial volumes: This law states that the volume of a mixture of gases (or the volume of the container) simply is the sum of the partial volumes of the individual components. Amagats law is as follows:
:and all component gases and the mixture are at the same temperature and pressure
:where V is the total volume of the gas mixture or the volume of the container,
:V is the partial volume, or volume of the component gas at the given pressure and temperature.
;Henry's law: This states that at constant temperature, the amount of a given gas dissolved in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid. The equation is as follows:
;Real gas law: This was formulated by Johannes Diderik van der Waals in 1873.