Question

A gaseous hydrocarbon gives upon combustion, 0.72 g of water and 3.08 g of `CO_(2)`. The empirical formula of the hydrocarbon is
A. (a)`C_(2)H_(4)`
B. (b)`C_(3)H_(4)`
C. (c )`C_(6)H_(5)`
D. (d)`C_(7)H_(8)`

Answer 1

Correct Answer - D
`18 g H_(2)O` contain `2 g H`.
`:. 0.72 g H_(2)O` contain `0.08 g H`
`44 g CO_(2)` contain `12 g C`.
`:. 3.08 g CO_(2)` contain `0.84 g C`.
`:. C.H.=0.84/12:0.08/1=0.07:0.08=7:8`
`:.` Empirical formula`=C_(7)H_(8)`