The values of heat of combustion of ethane `(C_(2)H_(6))` and ethyne `(C_(2)H_(2))` are `-341` and `-310 Kcal` respectively. Then which of the following is better fuel on mass basis:

Options

A. `C_(2)H_(2)`
B. `C_(2)H_(4)`
C. Both of these
D. None of these

Answer

B

Explanation

`Delta H " for " C_(2)H_(4) = -341.1` Kcal
its calorific value `= (-341.1)/(28)= -12.1` kcal/g.
`Delta H` for `C_(2)H_(2)= -310.0` kcal
its Calorific value `= (-310.0)/(26)= -11.92`
Hence `C_(2)H_(4)` is a better fuel.