If a reaction, A+B→C is exothermic to the extent of 30 kJ/mol and the forward reaction has an activation energy 70 kJ/mol, the activation energy for the reverse reaction is (in kJ/mol):
In an exothermic reaction A→B, the activation energy of reverse reaction is twice that of forward reaction. If enthalpy of the reaction is -80 kJ mol−1, the activation energy of the reverse reaction is :