The standard molar enthalpies of formation of cyclohexane (l) and benzene (l) at `25^(@)C` are `-156` and `+49 kJ mol^(-1)`, respectively. The standard enthaly of hydrogenation of cyclohenxene (l) at `25^(@)C` is `-119 kJ mol^(-1)` Use this data to estimate the magnitude of the resonance enegry of benzene.A. `152 kJ mol^(-1)`B. `-240 kJ mol^(-1)`C. `-152 kJ mol^(-1)`D. `240 kJ mol^(-1)`

The standard molar enthalpies of formation of cyclohexane (l) and benz

1.	The standard molar enthalpies of formation of cyclohexane (l) and benzene (l) at `25^(@)C` are `-156` and `+49 kJ mol^(-1)`, respectively. The standard enthaly of hydrogenation of cyclohenxene (l) at `25^(@)C` is `-119 kJ mol^(-1)` Use this data to estimate the magnitude of the resonance enegry of benzene.A. `152 kJ mol^(-1)`B. `-240 kJ mol^(-1)`C. `-152 kJ mol^(-1)`D. `240 kJ mol^(-1)`
Answer» Correct Answer - C `6C + 6H_(2) rarr C_(6) H_(12) , -156` ....(1) `6C + 3H_(2) rarr C_(6)H_(6) , + 49`...(2) `C_(6) H_(10) + H_(2) rarr C_(6)H_(12) , -119` `rArr C_(6)H_(6) + 3H_(2) rarr C_(6) H_(12) , -119 xx 3`...(3) ltbr. [Obseved ]from (1) and (2) `C_(6)H_(6) + 3H_(2) rarr C_(6) H_(12) -205` [Calculated] `,.` Reasonance energy `= (Delta H)_("obs") ~ (Delta H)_("cal")`

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