. Write any four postulates of kinetic molecular theory of gases.

Each gas is made up of a large number of small (tiny) particles known as molecules.

The volume of a molecule is so small that it may be neglected in comparison to total volume of gas.

The moelcules are never in stationary state but they are believed to be in chaotic (random) motion. They travel in straight line in all possible directions with altogether different but constant velocities. The direction of motion is changed by the collision with container or with other molecules.

The molecules are perfectly elastic and bear no change in energy during collison.

The effect of gravity on molecular motion is negligible.

The temperature of gas is a measure of its kinetic energy.

The pressure of the gas is thus due to the continuous collision of molecules on the walls of container. Pressure P = Force/Area.