Charles law Definition

Aug 26, 2022, 16:45 IST

Charles law Definition

Charles made measurements of the volume of a fixed mass of a gas at various temperatures under the condition of constant pressure and found that the volume of the gas is a linear function of the temperature.

Charles law Experiments 

Experiments have shown that when 273 ml sample of a gas at 0oC is heated to 1oC, its volume increases by 1 ml, i.e., it becomes 274 ml. At 10oC, the volume increases to 283 ml if the pressure remains constant in both cases. Similarly, when 273 ml sample of gas at 0oC is cooled to −1oC, its volume decreases to 272 ml while at −10oC the volume decreases to 263 ml if the pressure remains constant.

Charles law examples 

Thus, all gases expand or contract by the same fraction of their volumes at 0oC per degree change of temperature, i.e., for each degree change of temperature, the volume of a sample of a gas changes by the fraction 1/273 of its volume at 0oC.Let the volume of a given amount of a gas be Vo at 0oC. The temperature is increased by toC and the new volume becomes Vt.

Charles law formulas and graphs

Detail explanation and graph of Charles law is explained in the below mentioned pdf 

The volume of a given amount of a gas at constant pressure varies directly as its absolute temperature. 

V directly proportional to  T (if pressure is kept constant)

Since volume is directly proportional to Kelvin temperature, the volume of a gas should theoretically be zero at Kelvin zero. However, gases liquefy and then solidify before this low temperature is reached. In fact, no substance exists as a gas at a temperature near Kelvin zero, through the straight-line plots can be extrapolated to zero volume. The temperature that corresponds to zero volume is −273.15oC.