Question

What happens when gas is cooled?

Answer 1

• According to the kinetic theory of gases, the kinetic energy of the molecules of a gas is directly proportional to the absolute temperature.
• As the gas is cooled, the kinetic energy of the constituent molecules decreases as the temperature decreases. The molecules move slower than usual. The intermolecular space decreases.
• So, there is a decrease in volume.
• This leads to a change of the gaseous state into a liquid state.
• Hence, gases contract when they are cooled.