One Kilogram of a diatomic gas is at pressure of 8 x104N/m2  The density of the gas is 4kg/m3. What is the energy of the gas due to its thermal motion?

For a diatomic molecular gas internal energy per molecule is,U=52NKB THowever , PV=NKBT. Therefore, the total energy isU=52PVAlso , We Know that V=massdensity=14m3Therefore,U=52x 8 x 104 x 14=5x104J