The volume of a given mass of gas varies inversely with pressure, provided that the
temperature remains constant because
1. the average Kinetic energy of the molecules of a gas is proportional to the absolute temperature.
2.attractive forces between gas molecules are appreciable.
3.collisions between gas molecules are perfectly elastic.
4.Increasing the molecular concentration at constant temperature means increasing the number of collisions between molecules and container
5.attractive forces between a molecule are negligible.