A mixture of `NO_(2)` and `N_(2)O_(4)` has a vapour density of 38.3 at 300 K. What is the number of moles of `NO_(2)` in 10 moles of the mixture ?

Options

A. 0.043
B. 4.4
C. 3.4
D. 3.86

Answer

D

Explanation

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`