The enthalpy of formation for `C_(2)H_(4)(g)`, `CO_(2)(g)` and `H_(2)O(l)` at `25^(@)C` and `1` atm. Pressure be `52`, `-394` and `-286 kJ mol^(-1)` respectively. The enthalpy of combustion of `C_(2)H_(4)(g)` will be

Options

A. `+1412 kJ mol^(-1)`
B. `-1412 kJ mol^(-1)`
C. `+141.2 kJ mol^(-1)`
D. `-141.2 kJ mol^(-1)`

Answer

B

Explanation

`C_(2)H_(4)+3O_(2)to2CO_(2)+2H_(2)O` ,
`DeltaH=2(-286)+2(-394)-(52)=-1412kJ`