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:

Internal energy \(U = n_1 \frac{f_1}{2} RT + n_2 \frac{f_2}{2} RT\). For diatomic \(\text{O}_2\), \(f_1 = 5\), and for monoatomic \(\text{He}\), \(f_2 = 3\). Thus, \(U = 2 \left(\frac{5}{2}\right) RT + 4 \left(\frac{3}{2}\right) RT = 5RT + 6RT = 11RT\).