Charles' Law

Charles’ Law

Charles’ law states that for a fixed mass of gas, the volume of the gas is directly proportional to the absolute temperature of the gas provided the pressure of the gas is kept constant.
VαT V=kT V T =k


V 1 T 1 = V 2 T 2


  1. When temperature increases, the average kinetic energy of the gas particles will increase.
  2. The air molecule move faster and collide with the wall of the container more vigorously at higher frequency.
  3. As a result, the space between the gas particles increases and the volume of the gas increases.


  1. In the graphs above, the first graph shows that V is directly proportional to the absolute temperature.
  2. The second graph shows that, if the temperature is in oC, the graph does not pass through the origin.
  3. The third and the forth graphs shows that V/T is always constant for all value of V and T.