An ideal gaseou smixture of enthance `(C_(2)H_(6))` and enthene `(C_(2)H_(4))` occupies 28 litre at 1 atm and 273 K. The mixture reacts completely with 128 g `O_(2)` to produce `CO_(2)` and `H_(2)O` . Mole fraction at `C_(2)H_(6)` in the misture is ,

Options

A. 0.6
B. 0.4
C. 0.5
D. 0.8

Answer

a

Explanation

(a) Mole of `C_(2)H_(6)` and `C_(2)H_(4)` are `a and b` respectively.
`a+b=(28)/(22.4)=1.25`
`C_(2)underset(a)(H_(6)) "(g)"+3.5underset(3.5a)(O_(2))"(g)"rarr2CO_(2)"(g)"+3H_(2)O(l)`
`C_(2)underset(b)(H_(4)) "(g)"+3underset(3b)(O_(2))"(g)"rarr2CO_(2)"(g)"+2H_(2)O(l)`
Moles of `O_(2)=3.5a+3b=4`
`a+b=1.25`
`a=0.5`
`b=0.75`