When `100 ml` sample of methane and ethane along with excess of `O_(2)` is subjected to electric spark, the contraction in volume was observed to be `212 ml`. When the resulting gases were passed through `KOH` solution, further contraction in volume was

Options

A. `60 ml`
B. `96 ml`
C. `108 ml`
D. `124 ml`

Answer

D

Explanation

`{:(CH_(4)(g),+,2O_(2)(g),rarr,CO_(2)(g),+,2H_(2)O(l)),(x,,2x,,x,,):}`
`C_(2)H_(6)(g)+(7)/(2)O_(2)(g)rarr2CO_(2)(g)+3H_(2)O(l)`
`(100-x)(7)/(2)(100-x) 2(100-x)`
Total contraction in volume
`2x+2.5 (100-x)= 212`
`2x-2.5x= 212-250`
`x=38xx2= 76`
Therefore, contraction in volume when passed through `KOH` solution
`=` Volume of `CO_(2)` evolved
`x+2(100-x)= 124ml`