Question

The heat of combustion of `CH_(4) is -400 KJ mol^(-1)`. Calculate the heat released when 40g of `H_(2)O` is formed upon combustion :-
A. `+444.4 KJ`
B. `+888.8 KJ`
C. `-444.4 KJ`
D. `-888.8 KJ`

Answer 1

Correct Answer - C
`CH_(4)+2O_(2)toCO_(2)+2H_(2)O,=-400KJ//mol`
`because` for 2mole or 36 gm water, heat released `=-400KJ//mol`
`:.` for gm water, heat released will be
`=(-400)/(36)xx40`
`-444.44 KJ`