<Dd> V ∝ T (\ displaystyle V \ propto T \,), or </Dd> <Dd> V / T = k 2 (\ displaystyle V / T = k_ (2)), or </Dd> <Dd> V 1 / T 1 = V 2 / T 2 (\ displaystyle V_ (1) / T_ (1) = V_ (2) / T_ (2)), </Dd> <P> where V is the volume of a gas, T is the absolute temperature and k is a proportionality constant (which is not the same as the proportionality constants in the other equations in this article). </P>

The pressure of an ideal gas is inversely proportional