An ideal gas is held in a container at temperature T. The total internal energy of one mole of a monatomic gas is:
- $\frac{3}{2} RT$
- $\frac{5}{2} RT$
- $\frac{7}{2} RT$
- $RT$
Show answer and solution
Correct answer: A. $\frac{3}{2} RT$
**Monatomic:** 3 translational DOF. U = (3/2)RT per mole.
**For diatomic (rigid):** (5/2)RT
polyatomic with vibrations: (7/2)RT+.