Question

. The vapour density of a mixture of NO, and N204
is 39 at 25°C. What is the mass of NO, present
in 100 g of the mixture?
(1) 17.9 g
(2) 8.4 g
(3) 33.2 g
(4) 66.4 g​

Answer 1

Answer:

33.2gr

Explanation:

Let us take the mass of NO=X gr and N2O4=Y gr

given VD of the mixture=39

then Molecular weight of the Mixture=2×VD=2×39

=78gr

i.e)X+Y =78 ---------(1)

In Both NO and N2O4 ration of atoms is

X/Y=1/2==>Y=2X

now substut X value in equation 1 then we get

X+2X=78

3X=78--->X=26,and Y=52

i.e)78 gr of mixture contains 26 gr of NO

100 gr contains=26×100/78=33.2 gr