Question

1. the diagram to the left shows the distribution of speeds for a sample of o₂(g). which of the following graphs shows the distribution of speeds for the same sample at a higher temperature (dashed line)?

Explanation:

Step1: Recall kinetic - molecular theory

As temperature increases, the average kinetic energy of gas molecules increases.

Step2: Understand speed - distribution changes

The Maxwell - Boltzmann distribution of speeds of gas molecules broadens and the peak shifts to higher speeds at higher temperatures. The total area under the curve (representing the total number of molecules) remains the same.

Step3: Analyze each option

• Option A: The peak is at a lower speed for the dashed line, which is incorrect for a higher - temperature situation.
• Option B: The peak of the dashed line is at a lower speed, wrong for higher temperature.
• Option C: The dashed line is broader and the peak is at a higher speed compared to the solid line, which is consistent with an increase in temperature.
• Option D: The dashed line has a lower peak height but is not broadened and shifted to higher speeds in the correct way.

Answer:

C.