What is the effect of size of the gas molecules on their deviation from ideal

behaviour?

In low pressure range volume correction of the gases like N2 is negligible

but pressure correction is considerable wat is the reason?

Hi,

In the kinetic theory of the gases ,there is a faulty assumption that the size of a gas molecule is negligible campared to the volume of the gas .

This assumption is wrong if the gas is constrained to the very high pressure .Hence there is deviation of the gas from ideal behaviour.

At a very low pressure ,the gas molecules are very far apart from each other ,so in the case volume of individual gas molecule is negligible compared to the total volume of the gas .Hence, volume correction is ignored.

pressure correction mainly corrects the observed pressure of a gas .See basically pressure exerted by a gas is mainly due to the collisions of the gas molecules with the walls of the container.Actually gas molecules exert intermolecular forces of attraction on one another.So a gas molecule which is about to strikethe walls of a container will finally strike with a lesser momentum since it has been pulled by neighbourhood gas molecules. So the observed pressure will be smaller.

This is pressure correction.It cant be ignored.