Question

Equal moles of hydrogen and oxygen gases are placed in a container with a pin-hole through which both can escape. What fraction of the oxygen escapes in the time required for one-half of the hydrogen to escape?

(A) $3 / 8$

(B) $1 / 2$

(C) $1 / 8$

(D) $1 / 4$

Answer 1

Let the number of moles of each gas $=x$

Fraction of hydrogen escaped $=\frac{1}{2} x$

$\begin{array}{l}\Rightarrow \frac{n_{\mathrm{O}_2} / t}{\frac{x}{2} / t}=\frac{1}{4} \Rightarrow n_{\mathrm{O}_2}=\frac{1}{8} x \\\end{array}$

Hence, fraction of oxygen escaped $=\frac{1}{8}$

So, The correct option of this question will be (C).