Question

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

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

Answer 1

The correct option is A $1/3$

The fraction of total pressure exerted by oxygen will be equal to mole fraction of oxygen gas present in mixture of $C{H}_4$ and $O_2$.

Partial pressure of a component = Mole fraction × total pressure

Partial pressure of $O_2$ $/$ Total pressure = mole fraction of $O_2=\frac{\left(m/32\right)}{(m/32+m/16)}=1/3$