At \( 25^{\circ} \text{C} \) and \( 1 \) \( \text{atm} \) pressure, the enthalpies of combustion are as given below:
The enthalpy of formation of ethane is:
\( +54.0 \) \( \text{kJ mol}^{-1} \)
\( -68.0 \) \( \text{kJ mol}^{-1} \)
\( -86.0 \) \( \text{kJ mol}^{-1} \)
\( +97.0 \) \( \text{kJ mol}^{-1} \)