How many rotational degrees of freedom does a rigid diatomic molecule have?

Supposing the distance between the atoms of a diatomic gas to be constant,its specific heat at constant volume per mole (gram mole) is

The number of translational degrees of freedom for a diatomic gas is

State and explain the law of equipartition of energy.

An ideal gas has molecules with $5$ degrees of freedom. The ratio of specific heats at constant pressure $(C_p)$ and at constant volume $(C_v)$ is

At $STP$,the speed of a sound wave in a gas is $330 \ m/s$ and the density of the gas is $1.3 \ kg/m^3$. Calculate the degrees of freedom $(f)$ of the gas.