Explanation:
Gases are the state of mater in which molecules are far apart from each other as they are held by weak Vander waal forces. As a result, particles of a gas have high kinetic energy and hence, more number of collisions occur between them.
Due to this particles of a gas diffuse readily into its surroundings.
So, when gases are compressed then its molecules come closer to each other due to which more number of collisions take place. So, there will be increase in kinetic energy of the molecules and excess of energy is given off by the molecules and this will lead to increase in temperature of system.
On the other hand, when gases expand then its molecules move further apart from each other. Due to this there will be very less number of collisions take place. As a result, there will be decrease in temperature of the system.
Hence, we can conclude that when gases in a system are compressed, the energy of the system increases and the temperature of the system increases. When gases in a system expand, the energy of the system decreases and the temperature of the system decreases.
