Answer:
A. 45500 J
Step-by-step explanation:
Internal energy of diatomic gas is:
U = 5/2 nRT
where n is the number of moles,
R is the universal gas constant,
and T is the absolute temperature.
Given n = 7.00 mol, R = 8.31 J/mol/K, and T = 40+273 = 313 K:
U = 5/2 (7.00 mol) (8.31 J/mol/K) (313 K)
U = 45500 J