Q 11-12-017NEETJEE MainEasy
The total translational kinetic energy of $2$ moles of a monatomic ideal gas at $300$ K is about ($R = 8.31$ J mol$^{-1}$ K$^{-1}$)
Answer: (C) $7.5$ kJ
Concept. Translational KE of $n$ moles: $E = \dfrac32nRT$.
Step 1. Substitute.
$$E = \frac32 \times 2 \times 8.31 \times 300 \approx 7479\ \text{J} \approx 7.5\ \text{kJ}$$
Answer. $7.5$ kJ (Option C).
Solution by Sreeraj P, M.Sc Physics