van der Waals Equation

Theory

1) Pressure correction:
This correction was done due to intermolecular forces of attraction between the gas molecules. Pressure exerted by a real gas is less than that by an ideal gas.

a is van der Waals constant, which depends on the intermolecular forces of attraction.

2) Volume correction:
As the volume occupied by gas molecules cannot be neglected at high pressure, so the molecules now have restricted volume to move.

B is van der Waals constant and n is number of moles of gas.

van der Waals equation is: