Question

Equal masses of methane and oxygen are mixed in an empty container at ${25}^{\circ }C$. The fraction of the total pressure exerted by oxygen is

• A. $\frac{1}{3}$
• B. $\frac{1}{2}$
• C. $\frac{2}{3}$
• D. $\frac{1}{3}\times \frac{273}{298}$

Answer 1

The correct option is A $\frac{1}{3}$

Fraction of total pressure depends on mole fraction
$X_{O_2}=\frac{\frac{1}{32}}{\frac{1}{32}+\frac{1}{16}}=\frac{1}{32}\times \frac{32}{3}=\frac{1}{3}$