Question

The temperature at which root mean square velocity of molecules of helium is the equal root mean square velocity of hydrogen at N.T.P is:

• A. $273k$
• B. $373k$
• C. $546k$
• D. $596k$

Answer 1

The correct option is A $273k$

$C_{rms}=\sqrt{\frac{3RI}{M}}$

Since given $RMS$ velocity of He and $H_2$ some

$\therefore \frac{T{H}_2}{M{H}_2}=\frac{T_{He}}{M_{He}}$

$\therefore \frac{2+3}{2}=\frac{T_{He}}{4}$

$\Rightarrow T_{He}=546k$

$=546-273$

$=273C^O$