Question

The percentage by mole of no2 in a mixture of no2 and no having average molecular mass 34 is

Answer 1

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 , x= 0.25 and y= 0.75

Percentage by mole of NO2 = x * 100 = 0.25*100 = 25%