Find the change in the internal energy of 32 g of a monatomic gas (M = 4 g / mol) with a temperature change of 10 K.

Given:
M = 4 g / mol;
mass m = 32 grams;
T1 = T;
T2 = T + 10;
Find: U2;

Solution:
Using the formula U1 = 3 * m * R * T / (2 * M) we find U2;
U2 = 3 * m * R * (T + 10) / (2 * M);
ΔU = 3 * m * R * (T + 10 – T) / (2 * M) = 3 * m * R * 10 / (2 * M) = 3 * m * R * 5 / (1 * M) = 15 * m * R / M = 15 * 10 ^ (- 3) * 8, 31/4 * 10 ^ (- 3) = 997, 32 J.