Question

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

Answer 1

Correct Answer - C
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 toal pressure be P
The pressure exerted by oxygen ( partial pressure )
`= X_(O_(2))xxP_("total") implies Pxx(1)/(3)` , Hence, (c ) is correct .