⚛️ Physics · Kinetic Theory · NEET & JEE

The molar heat capacity at constant volume of a diatomic ideal gas (R = 8.31) is:

Answer: 20.8 J/mol K.

A ≈20.8 J/mol K
B ≈12.5 J/mol K
C ≈29.1 J/mol K
D ≈8.31 J/mol K

Correct answer: A. ≈20.8 J/mol K

Explanation: C<sub>v</sub> = (5/2)R = 2.5 × 8.31 ≈ 20.8 J/mol K.

Not all gas molecules move at the same speed - the Maxwell-Boltzmann distribution shows the spread, with the most probable speed v_p slightly less than the average v_avg, which is slightly less than the root-mean-square speed v_rms used in the pressure formula.

Concept context

Kinetic theory of gases connects molecular motion to pressure and temperature, explaining gas laws, specific heats, and molecular speeds.

Read the full Kinetic Theory notes →

The molar heat capacity at constant volume of a diatomic ideal gas (R = 8.31) is:

Concept context

More Kinetic Theory questions