Question

Why do real gases deviate from ideal gas behavior?

Answer 1

As we know that real gases are the non ideal gases whose molecules occupy space and have interactions and also does not behave according to the assumptions of the kinetic theory of gases whereas an ideal gas is one that follows the gas laws at all conditions of temperature and pressure and to do so, the gas would need to completely abide by the postulates of kinetic theory of theory. So we have to explain the reasons behind the deviation of real gas from the ideal gas behavior.

Complete answer:
Let us discuss the postulates of kinetic theory of gases which were wrong for real gases as follows:-
(A) The volume occupied by gas molecules in the container is negligibly small as compared to the volume occupied by the gas.
This assumption is only valid at low pressures and high temperature conditions, when the volume occupied by the gas molecules is negligible as compared to the total volume of the gas in the container. But at low temperature or at high pressure conditions, the molecules being in compressible state and the volumes of molecules are no more negligible as compared to the total volume of the gas.
(B) The forces of attraction between gas molecules are almost negligible.
The second assumption is also not valid at high pressure and low temperature conditions. Real gases deviate from the ideal gas behavior because their molecules have interaction (force of attraction and repulsion) between them. At high pressure situations the molecules of gases are very close to each other due to which the molecular interactions start operating and these molecules do not strike the walls of the container with full impact.
-Above data shows the reason behind the deviation of real gases from ideal gas behavior.

Note:
-You need to understand the gaseous laws and kinetic theory of gases in order to solve these types of questions.
-Also the deviation from ideality can be known by the compressibility factor Z.