# Common gas laws

Boyle's Law: Boyle's Law defines the relationship between pressure and volume. It states that at a constant temperature, the volume of a given mass of gas will vary inversely with the absolute pressure, or P|Vi = P2V2.

Charles' Law: Charles' Law concerns the relationship between temperature, volume and pressure. It states that 'if the pressure remains constant, the volume of a given amount of gas is directly proportional to the absolute temperature'.

Dalton's Law: Dalton's Law concerns the composition of air at various pressures. It states that 'the total pressure exerted by a mixture of gases is the sum of the pressures that would be exerted by each of the gases if it alone occupied the total volume'. The total pressure is the sum of the partial pressures of the gases present and as the overall pressure increases, so the partial pressure of the constituent gases increases.

Henry's Law: Henry's Law relates to gas absorption in fluids. It states that 'the amount of gas that will dissolve in a liquid at a given temperature is directly proportional to the partial pressure of that gas over the liquid'. At increased pressures, increased volumes of gas can dissolve in liquid.