For the complete combustion of ethanol, `C_(2)H_(5)OH(l)+3O_(2)(g)rarr2CO_(2)(g)+3H_(2)O(l)` the amount of heat produced as measured in bomb calorimeter is `1364.47KJ mol^(-1)` at `25^(@)C` . Assuming ideality, the enthalpy of combustion, `DeltaH_(C)` , for the reaction will be
`[R=8.314JK^(-1)mol^(-1)]`

Options

A. ` - 1366.95 " kJ mol "^(-1)`
B. ` -1361.95 "kJ mol"^(-1)`
C. `- 1460.50 "kJ mol"^(-1)`
D. `- 1350.50 "kJ mol"^(-1)`

Answer

A

Explanation

`C_2H_5OH(l) +3O_(2(g)) rarr 2 CO_(2(g))+3H_2O_((l))`
`Delta U= -1364.47 kJ // mol `
`Delta H=Delta U+ Delta n_g RT " but" Delta n_g =-1`
`Delta U= -1364.47 kJ// mol `
`Delta H = Delta U+ Delta n_g " RT but " Delta n_g =-1`
`Delta H= -1364.47 +[(-1 xx 8.314 xx 298)/(1000)]`
`= -1364.47 -2.4776 =-1366.94 kJ// mol`