Q76 / 180 · AIIMS 2010 · Chemistry
Equal weight of $\mathrm{CO}$ and $\mathrm{CH}_4$ are mixed together in an empty container at $300 \mathrm{~K}$. The fraction of total pressure exerted by $\mathrm{CH}_4$ is
- A$\frac{16}{17}$
- Correct answerB$\frac{7}{11}$
- C$\frac{8}{9}$
- D$\frac{5}{16}$
Solution
Let the weight of $\mathrm{CO}=$ weight of $\mathrm{CH}_4=a \mathrm{~g}$
Moles of $\mathrm{CO}=\frac{a}{28}$
Moles of $\mathrm{CH}_4=\frac{a}{16}$
Total moles $=\frac{a}{28}+\frac{a}{16}$
$$
x_{\mathrm{CH}_4}=\frac{\frac{a}{16}}{\frac{a}{28}+\frac{a}{16}}=\frac{a}{16} \times \frac{28 \times 16}{44 a}=\frac{14}{22}=\frac{7}{11}
$$
$\therefore$ Fraction of pressure exerted by $\mathrm{CH}_4=7 / 11$.
Hence, the correct answer is option: 'B'.