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In the gaseous state, let the most probable speed be represented by C*, the mean speed by C̅, and the root mean square speed by C. For a very large number of molecules, what is the correct ratio among these speeds?

1. C*: C̅: C = 1.225: 1.128: 1
2. C*: C̅: C = 1.128: 1.225: 1
3. C*: C̅: C = 1: 1.128: 1.225
4. C*: C̅: C = 1: 1.225: 1.128

Correct answer: C*: C̅: C = 1: 1.128: 1.225

Solution

C* : Cbar : Crms = sqrt2 : sqrt(8/pi) : sqrt3 = 1 : 1.128 : 1.225 (most probable smallest, rms largest). The stored ratio is reversed.

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