Unusual Stability Hydrogenation of just one double bond in benzene is endothermic! --(-85.8 predicted) 36 kcal (-57.2 predicted) resonance energy energy 1.8 kcal resonance energy -57.4 kcal -55.4 kcal -49.8 kcal -28.6 kcal energy Chapter 16 6 Unusual Stability Hydrogenation of just one double bond in benzene is endothermic! =>