What are the causes of deviation of real gases from its ideal behaviour?
The causes of deviations from ideal behaviour may be due to the following two assumptions of kinetic theory of gases.
1. The volume occupied by gas molecules is negligible as compared to the volume occupied by the gas.
2. The forces of attraction between gas molecules are negligible.
The first assumption is valid only at low pressures and high temperature, when the volume occupied by the gas molecules is negligible as compared to the total volume of the gas. But at low temperature or at high pressure, the molecules being in compressible the volumes of molecules are no more negligible as compared to the total volume of the gas.
The second assumption is not valid when the pressure is high and temperature is low. But at high pressure or low temperature when the total volume of gas is small, the forces of attraction become appreciable and cannot be ignored.
