In certan areas where coal is cheap, artificial gas is produced for household use by the ''water gas'' raction
`C(s) +H_(2)O(g) underset(600^(@)C)rarr H_(2)(g) +CO(g)`
Assuming that coke is `100%` carbon, calculate the maximum heat obtainable at `298K` from the combustion of `1kg` of coke, and compare this value to the maximum heat obtainable at `298K` from burning the water was produced from `1.00 kg` of coke.
GIven: `Delta_(f)H^(Theta), H_(2)O(l) =- 68.32 kcal//mol`
`Delta_(f)H^(Theta),CO_(2) (g) =- 94.05 kcal//mol`
`Delta_(f)H^(Theta),CO(g) =- 26.42 kcal//mol`

Explanation

`C(s) +O_(2)(g) rarr CO_(2)(g), DeltaH =- 94.05 kcal mol^(-1)`
Maximum heat obtainable form the combustion of
`1.0 kf of coke =- (94.05)/(12) xx 1000 =- 7840 cal`
Moles of carbon in `1kg` of coke `= (1000)/(12) = 83.3`
Maximum heat obtainable from burning the water gas produced from `1kg` of coke
`= (83.3) [(-68.32) +(67.6)]`
`=- 11320.47 kcal`
More energy is obtainable from water gas.