What correction did Van der Waals introduce to the ideal gas law?

Van der Waals introduced significant modifications to the ideal gas law by factoring in the finite volume occupied by gas molecules. In the ideal gas law, it is assumed that gas particles have no volume and that they do not interact with one another. However, in reality, gas molecules do occupy space, which can affect the pressure and behavior of the gas.

Van der Waals adjusted the equation to include a term that accounts for the volume occupied by the gas molecules. This adjustment recognizes that the volume available for the movement of gas particles is reduced when the volume of the particles themselves is considered, leading to a more accurate prediction of gas behavior under various conditions, especially at high pressures and low temperatures, where interactions and the size of particles become more significant.

This correction reflects the reality that real gases do not behave ideally under all conditions and allows for a better understanding of their behavior in practical situations.