Answer: halved.
- A doubled
- B halved
- C unchanged
- D four times
Correct answer: B. halved
Explanation: Mean free path ∝ 1/n; doubling pressure at constant T doubles n, so the mean free path is halved.
Not all gas molecules move at the same speed - the Maxwell-Boltzmann distribution shows the spread, with the most probable speed vp slightly less than the average vavg, which is slightly less than the root-mean-square speed vrms 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.