80 kJ mol-1
60 kJ mol-1
20 kJ mol-1
40 kJ mol-1
Eact (reverse) = 20 + 60 = 80 kJ
For the reaction A+B→C+D ΔH=−20 kJ mol−1 . The activation energy of the forward reaction is 85kJ mol–1. The activation energy for backward reaction is