Calculate the volume (in cm 3 ) of air expelled from a vessel containing 0.4 litres of it at 250 K, when it is heated to 27°C at the same pressure.

1 lit = 1000 cm 3 ∴ 0.4 lit = 400 cm 3 V 1 = Initial volume of the gas = 400 cm 3 T 1 = Initial temperature of the gas = 250 K T 2 = Final temperature of the gas = 27°C = 27 + 273 = 300 K V 2 = Final volume of the gas = ? By Charles' Law: Substituting the values : Volume of air expelled = 480 - 400 = 80 cm 3