Physics - Heat & Thermo Question with Solution | TestHub

The internal energy of an ideal gas is a state function and is given by, $U=n{C}_{v}T$.

For monatomic gas, $C_v=\frac{3}{2}R$.

Therefore, $U=2\times \frac{3}{2}\times 8.31\times 300=7479 \mathrm{J}$