A vessel contains a mixture of one mole of oxygen and two moles of nitrogen at 300K. The ratio of the average rorational kinetic energy per `O_2` molecules to that per `N_2` molecules is

Options

A. `1:1`
B. `1:2`
C. `2:1`
D. Depends on the moments of inertial of the two molecules

Answer

A

Explanation

Kinetic energy per degree of freedom = `1/2 kt` as diatomic gas possess two degree of freedom for rotational motion therefore, rotational K.E. =`2(1/2 kT) = kT`. In the problem both gases (oxygen and nitrogen) aroe diatomic and have same temperature `(300K)` therefore, ratio of average rotational kinetic energy will be equal to one.