Question

What is molar internal energy of oxygen at 25 ◦c, taking into account its translational degree of freedom and rotational degree of freedom ?

Answer 1

Internal energy (U) is given as:

Number of moles (n) x Temperature of gas (K) x Heat capacity at constant volume (Cv)

Heat capacity for O2 is 5R/2 since it is a diatomic molecule

Therefore substituting values of n = 1, K = 298K

U = 1490 (Units in terms of calories, R = 2 cal)