Question

RMS velocity of oxygen molecules at NTP is $0.5km/s$. The RMS velocity for the hydrogen molecule at NTP is

• A. $4km/s$
• B. $2km/s$
• C. $3km/s$
• D. $1km/s$

Answer 1

Answer: (B)

RMS velocity of molecules at NTP
$V_{rms}=\sqrt{\frac{3RT}{M}}$
RMS velocity of oxygen molecules at $NTP$
$\left(v_1\right)=\sqrt{\frac{3RT}{M_1}}=0.5km/s$
RMS velocity of hydrogen molecules at NTP
$\left(v_2\right)=\sqrt{\frac{3RT}{M_2}}$
$\Rightarrow \frac{V_1}{V_2}=\sqrt{\frac{M_2}{M_1}}$
$\Rightarrow \frac{0.5}{v_2}=\sqrt{\frac{2}{32}}$
$\Rightarrow \frac{0.5}{V_2}=\frac{1}{4}$
$v_2=2km/s$