Charle's law

(1) French chemist, Jacques Charles first studied variation of volume with temperature, in 1787.

(2) It states that, “The volume of a given mass of a gas is directly proportional to the absolute temperature (=°C+273) at constant pressure”.

Thus, V ∞ T at constant pressure and mass

 or V=KT=K(t(°C) + 273.15),   (where k is constant),     

 or  (For two or more gases)

Thus, for every 1° change in temperature, the volume of a gas changes by 1/273.15 ≈ (1/273) of the volume at 0°C.