The percentage by mole of NO2 in a mixture of NO2 and NO are having average molecular mass 34 is
Lets assume that the mole fraction of NO2 is ‘x’ and NO is ‘y’.
Now lets assume that the container contains only these two gases. So we can say that,
x+y=1
Now we know that molecular weight of NO2 is 46 and that of NO is 30. Now,the avg molecular mass is given by
M1.x +M2.y=34;
where M1 and M2 are the individual molecular masses.
Now solving the two equations we find that ,
Mole percentage as
x= 0.25 and y= 0.75
Mole percentage of NO2=25
Mole percentage of NO=75