Question

What is the internal energy of 2.00 mol of diatomic hydrogen gas (H2) at 35°C?

I think the formula is (5/2) (NRT) but I'm not sure If i am supposed to multiply everything by 5 and then take the square root or just multiply the 5/2 into the equation...please help!!

Answer 1

Answer: why are all of the websites reporting the answer of 32008J ? The answer should be 12797.4J.

Explanation: KE= (5/2)*2*8.31*(35+273) = 12797.4. Can anyone tell me why the answer is 32008?

Answer 2

As you mentioned, we will use Equipartition Theorem.
H2 has 5 degrees of freedom; 3 translations and 2 rotation
Therefore:
Internal energy = (5/2) nRT
You just substitute in the equation with the values of R and T and calculate the internal energy as follows:
Internal energy = (5/2) x 2 x 8.314 x 308 = 32.0089 x 10^3 J