What is the internal energy of 2.00 mol of an ideal diatomic gas at 765 k , assuming all degrees of freedom are active?

The internal energy of an ideal gas is given by:

where 
k is the number of degrees of freedom of the molecules of the gas
n is the number of moles
R is the gas constant
T is the absolute temperature.

For a diatomic gas, k=5. In our problem, the number of moles is n=2.00 and the absolute temperature of the gas is T=765 K, so its internal energy is

The answer is b hope this