Using the following data, calculate the heat of combustion of cyclohexatrieneandalso find the resonance energy of benzene.
`Delta_(C)H^(ɵ)` (Benzene)`=-789kcal mol^(-1)`
Combustion contribution `(C-H)=-54.0kcal`
Combustion contribution `(C-C)=-49.3kcal`
Combustion contribution `(C=C)=-117.7kcal`
Strategy: First write a balanced equation for the combustion of one mole of cyclohexatriene:
Nowusing the structure, calculate the combution contribution for each bond and do the total for the molecule.

Explanation

Three `C=C` bonds`=3xx(-117.7)=-353.1kcalmol^(-1)`
Three `C-C` bonds`=3xx(-49.3)=-147.9kcalmol^(-1)`
Six `C-H` bonds`=6xx(-54.0)=-324.0kcalmol^(-1)`
`overline(S um=-825.0kcalmol^(-1))`
Thus, the calculated heat of combustion for cyclohexatriene is `-825.0kcalmol^(-1)`
Defference`=[(-789.1 kcal mol^(-1))-(-825.0 kcal mol^(-1))]`
`=35.9 kcal mol^(-1)`