Question

If the rate of effusion of helium gas at a pressure of $1000$ torr is $10$ torr ${\min }^{-1}$. Find the rate of effusion of hydrogen gas at a pressure of $2000$ torr at the same temperature.

• A. 20 torr ${\min }^{-1}$
• B. 10 torr $mi{n}^{-1}$
• C. $30\sqrt{2}$ torr $mi{n}^{-1}$
• D. $20\sqrt{2}$ torr $mi{n}^{-1}$

Answer 1

Answer: (D)

At a given temperature, rate of effusion $P$ and $1/\sqrt{M}$
Rate of effusion of hydrogen gas
$=10$ torr ${\min }^{-1}\times \frac{2000}{1000}\times \sqrt{(4/2)}$
$=20\sqrt{2}$ torr ${\min }^{-1}$