(a) How many liters of hydrogen at 1.00 atm and 298 K are needed to hydrogenate

(i) 1.00 mol C₆H₁₀, cyclohexene; (ii) 1.00 mol C₆H₆, benzene, completely?

(b) Estimate the reaction enthalpy of each hydrogenation from the average bond enthalpies in Tables 4E.2 and 4E.3.

(c) A Kekulé structure of benzene suggests that its enthalpy of hydrogenation should be three times that of cyclohexene. Do your calculations support this implication? Explain any differences.

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TABLE 4E.2 Bond Enthalpies of Diatomic Molecules Molecule H N 0 CO F2 Cl Br 1 HF HCI HBr HI AHB/(kJ.mol-) 436 944 496 1074 158 242 193 151 565 431 366 299