Question
At 25$^\circ$C and 1 atm pressure, the enthalpies of combustion are as given below :
| Substance | ${H_2}$ | C (graphite) | ${C_2}{H_6}(g)$ |
|---|---|---|---|
| ${{{\Delta _c}{H^\Theta }} \over {kJ\,mo{l^{ - 1}}}}$ | $ - 286.0$ | $ - 394.0$ | $ - 1560.0$ |
The enthalpy of formation of ethane is