(i) the fraction of molecules with most probable kinetic energy decreases at higher temperatures.

(ii) the fraction of molecules with most probable kinetic energy increases at higher temperatures.

(iii) most probable kinetic energy increases at higher temperatures.

(iv) most probable kinetic energy decreases at higher temperatures.

Correct Answers:

(i) the fraction of molecules with most probable kinetic energy decreases at higher temperatures.

(iii) most probable kinetic energy increases at higher temperatures.

Explanation: According to Maxwell Boltzmann distribution of energy, the fraction of molecules with most probable kinetic energy decreases at higher temperatures and the most probable kinetic energy increases at higher temperatures.