The heat of hydrogenation of cyclohexene is $- 120 kJ mo l^{- 1}$ and that of benzene is $- 208 kJ mo l^{- 1}$ . The resonance energy of benzene, in $kJ mo l^{- 1}$ , estimated with this data is

Answer: C

Hypothetical cyclohexatriene with three isolated double bonds would release

3 \times 120 = 360 kJ mo l^{- 1}

. The measured value is 208, so resonance energy

= 360 - 208 = 152 kJ mo l^{- 1}