Equal masses of methane and oxygen are mixed in an empty container at `25^(@)C`. The fraction of the total pressure exerted by oxygen is:

Options

A. `(2)/(3)`
B. `(1)/(3)xx(273)/(298)`
C. `(1)/(3)`
D. `(1)/(2)`

Answer

C

Explanation

Let the mass of methane and oxygen is w
`"mole fraction of oxygen"=((w)/(32))/((w)/(32)+(w)/(16))`
`=((1)/(32))/((1)/(32)+(1)/(16))=((1)/(32))/((3)/(32))=(1)/(3)` Let the total pressure be P
The pressure exerted by oxygen (partial pressure)
`X_(O_(2))xxP_("total")rArr Pxx(1)/(3)`. Hence (C) is correct.