Resonance Energy Benzene does not have the predicted heat of hydrogenation of-359 kJ/mol. The observed heat of hydrogenation is -208 kJ/mol,a difference of 151 kJ. This difference between the predicted and the observed value is called the resonance energy. Chapter 16 7Chapter 16 7 Resonance Energy • Benzene does not have the predicted heat of hydrogenation of -359 kJ/mol. • The observed heat of hydrogenation is -208 kJ/mol, a difference of 151 kJ. • This difference between the predicted and the observed value is called the resonance energy