1. Avogadro's law states that, "equal volumes of all gases, at the same temperature and pressure, have the same number of molecules."

2. So, from Avogadro law, at same temperature all the ideal gases will have same volume.

3. As we know that kinetic energy of ideal gas is given by

……(i)

Where K. E=kinetic energy of gas

k_B = Boltzmann constant

T = temperature of gas

4. Temperature is a quantity that is dependent on number of molecule in kinetic theory of gases.

5. Again, from Avogadro law, at same temperature all the gases will have same number of molecules which is equal to Avogadro number.

6. In 1 mole of any gas, number of molecules are 6.02310²³.

7. Therefore, kinetic energy of 1 mole, will be same for all ideal gas at same temperature as all will contain same number of molecules.