(a) By using data in Appendix C, compare the heat of combustion of 1.0 mol C6H6(g) to the heat of combustion of 3.0 mol acetylene, C2H2(g). Which has the greater fuel value, 1.0 mol C6H6(g) or 3.0 mol C2H2(g)? Are your calculations consistent with benzene being especially stable? (b) Repeat part (a), with the appropriate molecules, for toluene (C6H5CH3), a derivative of benzene that has a —CH3 group in place of one H. (c) Another reaction you can use to compare molecules is hydrogenation, the reaction of a carbon–carbon double bond with H2 to make a C—C single bond and two C—H single bonds. The experimental heat of hydrogenation of benzene to make cyclohexane (C6H12, a six-membered ring with 6 C—C single bonds and 12 C—H bonds) is 208 kJ/mol. The experimental heat of hydrogenation of cyclohexene (C6H10, a six-membered ring with one C “ C double bond, 5 C—C single bonds, and 10 C—H bonds) to make cyclohexane is 120 kJ/mol. Show how these data can pro-vide you with an estimate of the resonance stabilization energy of benzene. (d) Are the bond lengths or angles in benzene, compared to other hydrocarbons, sufficient to decide if benzene exhibits resonance and is especially stable? Discuss. (e) Consider cyclooctatetraene, C8H8, which has the octagonal structure shown below. What experiments or calculations could you perform to determine whether cyclooctatetraene exhibits resonance?