Question

The rms speed of hydrogen molecules at room temperature $2400m{s}^{-1}$. At room temperature the rms speed of oxygen molecules would be :

• A. $400m{s}^{-1}$
• B. $300m{s}^{-1}$
• C. $600m{s}^{-1}$
• D. $1600m{s}^{-1}$

Answer 1

The correct option is C $600m{s}^{-1}$

RMS of $H_2=2400m{s}^{-1}$

$2400=\sqrt{\frac{3RT}{M}}{\left(2400\right)}^2=\frac{2\times RT}{2}3RT=2\times {\left(2400\right)}^2$

$M$ of $H_2=2$

For oxygen, $M=32$

rms speed $=\sqrt{\frac{3RT}{M}}=\sqrt{\frac{2\times {\left(2400\right)}^2}{32}}=600m{s}^{-1}$

Therefore, the option is C.