Question

Two containers are maintained at the same temperature. The first one has a volume of 8 litres and stores hydrogen at 2 atm. The other one has a volume of 4 litres and stores oxygen at 1 atm. What is the ratio of the root mean square velocities of hydrogen and oxygen?

• A. 4:1
• B. 1:4
• C. 1:16
• D. 16:1

Answer 1

The correct option is A 4:1

$v_{rms}=\sqrt{\frac{3RT}{M}}$
Since the temperature is constant, the velocities will only depend on the molecular masses of the gases stored.
$\frac{v_{rms{H}_2}}{v_{rms{O}_2}}=\sqrt{\frac{M_{O_2}}{M_{H_2}}}=\sqrt{\frac{32}{2}}=4$