Question

If the rms velocity of oxygen molecule at certain temperature is 0.5 km/s, the rms velocity for hydrogen molecule at the same temperature will be:

• A. 2 km/s
• B. 4 km/s
• C. 9 km/s
• D. 16 km/s

Answer 1

Answer: (A)

2 km/s

Answer 2

$\frac{v_{O_{2}}}{v_{H_{2}}} = \sqrt{\frac{M_{H_{2}}}{M_{O_{2}}}} = \sqrt{\frac{2}{32}}$

$\frac{0.5}{v_{H_{2}}} = \sqrt{\frac{1}{16}} = \frac{1}{4}$