The Internal Energy for a Diatomic Gas Is Given by U

The internal energy for a diatomic gas is given by U = 5nRT/2. Calculate the internal energy of a 100 g mixture of oxygen 20%) and nitrogen 80%) gas at 25°C. The molar weight of O₂ = 32 g, and the molar weight of N₂ = 28 g.)

A) 21.6 kJ
B) 1.80 kJ
C) 12.1 kJ
D) 13.0 kJ
E) 1.10 kJ