In Exercise 89 in Chapter 8, the Lewis structures for benzene
\(\left(\mathrm{C}_{6} \mathrm{H}_{6}\right)\) were drawn. Using one of the
Lewis structures, estimate \(\Delta H_{\mathrm{f}}^{\circ}\) for \(\mathrm{C}_{6}
\mathrm{H}_{6}(g)\) using bond energies and given that the standard enthalpy of
formation of \(\mathrm{C}(g)\) is \(717 \mathrm{~kJ} / \mathrm{mol}\). The
experimental \(\Delta H_{\mathrm{f}}^{\circ}\) value of \(\mathrm{C}_{6}
\mathrm{H}_{6}(g)\) is \(83 \mathrm{~kJ} / \mathrm{mol} .\) Explain the
discrepancy between the experimental value and the calculated \(\Delta
H_{\mathrm{f}}^{\circ}\) value for \(\mathrm{C}_{6} \mathrm{H}_{6}(g)\)