⚛️ Physics · Kinetic Theory · NEET & JEE

A vessel holds 2 moles of helium and 3 moles of hydrogen at the same temperature T. The total internal energy of the mixture is:

Answer: 10.5 RT.

A 7.5 RT
B 12.5 RT
C 10.5 RT
D 5 RT

Correct answer: C. 10.5 RT

Explanation: Helium (monatomic): 2 × (3/2)RT = 3RT. Hydrogen (diatomic): 3 × (5/2)RT = 7.5RT. Total = 10.5 RT.

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.

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A vessel holds 2 moles of helium and 3 moles of hydrogen at the same temperature T. The total internal energy of the mixture is:

Concept context

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