Question

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
A. `1:1`
B. `1:2`
C. `2:1`
D. `2:1`

Answer 1

Correct Answer - A
Average kinetic energy per molecule per degree of freedom `=1//2kT` . Since both the gases are diatomic and are at same temperature `(300K)` , both will have the same number of rotational degree of freedom, i.e., two. Therefore, both the gases will have the same average rotational kinetic energy per molecule
`=2xx(1)/(2)kT=kT`
Thus, the ratio will be `1:1` .