Question

Equal weights of methane and oxygen are mixed in an empty container at `25^(@)C`. The fraction of the total pressure exerted by oxygen is
A. `(1)/(3)`
B. `(1)/(2)`
C. `(2)/(3)`
D. `(1)/(3)xx(273)/(298)`

Answer 1

Let `32 g` of each gas be present.
Moles of `O_(2)=32//32=1`
Moles of `CH_(4)=(32)/(16)=2`
Mole fraction of `O_(2)=(1)/(1+2)=(1)/(3)`
which is same as fraction of pressure.