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 enthalpy of hydrogenation of cyclohexane ( l ) at 25°C is -119 kJ mol−1 . Use these data to estimate the magnitude of the resonance energy of benzene. (IIT 1996)