Vapour density of the equilibrium mixture of `NO_(2) and N_(2) O_(4)` is found to be 40 for the equilibrium: `N _(2) O _(4) (g) hArr 2 NO _(2) (g).` Calculate percentage of `NO_(2)` in the mixture.

Options

A. 32
B. 26
C. 25
D. 35

Answer

C

Explanation

`N _(2) O _(4) hArr 2NO _(2)`
Initial moles
Moles at equilibrium `(1-x) 2x`
Hence, the total moles at equilibrium `= (1 + x) = 1 + 0. 15 = 1. 15`
`("mole of" NO _(2))/( "total moles") = (2 xx 0 15)/(1.15) xx 100` Percentage of `NO _(2) = 26.08 %`