Question

The rms speed of hydrogen at $27^{\circ} C$ is $v$. What will be the rms speed of oxygen at $300\, K$ ?

• A. 4 v
• B. 2 v
• C. v/2
• D. v/4

Answer 1

Answer: (D)

We use $v_{r m s}=\sqrt{\frac{3 R T}{M}}$
For hydrogen, $M=1$
For oxygen, $M=16$
$v=\sqrt{3 R T}$
$v_{O_{2}}=\sqrt{\frac{3 R T}{16}}=\frac{v}{4}$