Knowledge database: Basic laws of chemistry: Charles-Gay-Lussac's law

Charles-Gay-Lussac's Law tells us that, at conditions of constant pressure and constant amount of gas, the change of volume is proportional to the change of temperature. In its simplest way this law can be expressed with the formula V=const.*T, where V is the volume and T is the thermodynamic temperature.

The above mentioned formula would mean that the volume of an ideal gas tends to reach zero when the temperature approaches the value of of 0 kelvins. This would mean that the density of gas must have an infinite value at the temperature of 0 kelvins, which is impossible, and therefore it is also not possible to reach absolute zero, but extremly low temperatures have been successfully reached (even as low as 0.001 kelvins).

This law can be visualized with the help of the graph shown above. As one can see, the volume is proportional to the temperature, which means that by increasing temperature (at constant pressure and amount of gas) the volume will also increase, and vice versa.