Equal weights of methane and oxygen are mixed in an empty container at 25ºC. The fraction of the total pressure exerted by oxygen is

Let x gram of both gases are added. Number of moles for oxygen = given mass/ molecular mass= x/32 Number of moles for methane = given mass/ molecular mass= x/16 Mole fraction for oxygen = ( / 32) / ( / 32 /16) x x x =1/3. Partial pressure of hydrogen/ Total pressure= mole fraction of hydrogen= 1/3. Graham's Law of Diffusion and effusion