Kinetic Theory of Gases: Practice Problem & Solution

Solution Explained:

To solve this problem, we apply the core principles of Kinetic Theory of Gases. Understanding the underlying formula is key to arriving at the correct answer below:

$O_2$ is diatomic ($f=5$), $U_1 = n_1\frac{f_1}{2}RT = 2 \times \frac{5}{2}RT = 5RT$. Ar is monoatomic ($f=3$), $U_2 = n_2\frac{f_2}{2}RT = 4 \times \frac{3}{2}RT = 6RT$. Total energy $U = U_1 + U_2 = 5RT + 6RT = 11RT$.