When the pressure on the surface of a gas is increased, the inter-particle forces between gas molecules themselves do not change directly due to the increase in pressure. Pressure is the result of gas molecules colliding with the walls of their container, and an increase in pressure indicates that there are more frequent and forceful collisions occurring.
Inter-particle forces in a gas are primarily determined by factors such as the nature of the gas molecules (polar or nonpolar), their size, and their temperature. These forces include:
Van der Waals forces: These are weak intermolecular forces that include London dispersion forces (arising from temporary fluctuations in electron distribution) and dipole-dipole interactions (arising from permanent molecular dipoles). An increase in pressure does not directly affect these forces, as they depend more on the nature of the molecules.
Electrostatic interactions: In polar gases, permanent or induced dipoles can lead to electrostatic attractions between molecules. However, pressure changes do not have a direct impact on these forces.
Kinetic energy: An increase in pressure generally corresponds to an increase in gas molecules' kinetic energy and therefore their average speed. This heightened kinetic energy can lead to more frequent and energetic collisions between molecules, which might temporarily affect the arrangement of molecules in the gas.
In summary, while an increase in pressure can result in more collisions between gas molecules and the container walls, it doesn't directly alter the inter-particle forces between the gas molecules themselves. These forces are primarily influenced by factors such as the nature of the molecules, their temperature, and their relative positions.