The cohesive force between the molecules of all the gases is negligible. When gases expand, the molecules of all types of gases move away under similar conditions, therefore temperature coefficient of volume expansion of all the gases is same.
The cohesive forces between solids and liquids is different, and the molecules of solid and liquids is bonded by cohesive forces. When solids or liquids expand, the molecules move away against different cohesive forces. Therefore, temperature coefficient of volume expansion of different solids and liquids are different.
