Question

A mixture of `NO_(2)` and `N_(2)O_(4)` has a vapor density of `38.3` at 300 K. What is the number of moles of `NO_(2)` in 100 g of themixture ?
A. 0.043
B. 4.4
C. 3.4
D. 0.437

Answer 1

Correct Answer - D
Molecular wt. of mixture `= 2 xx V.d`
`2 xx 38.3=76.6`
wt. of `NO_(2) = x`
So that wt. of `N_(2)O_(4)=100-x`
Hence, `(x)/(46)+(100-x)/(92)=(100)/(76.6)=(2x+100-x)/(92)=(100)/(76.6)`
`x=20.10`,no. of mole of `NO_(2)=(20.10)/(46)=0.437`