1) For a reaction A → B: △ H =20kj mol-1 the activation energy of the forward reaction is 85kJ/mol. The activation energy of the backward reaction will be A) 105 kJ/mol B) 65 kJ/mol C) 45 kJ/mol D) 75 kJ/mol Answer: Option BExplanation:Energy of activation for forward reaction (Ea) =85 kj/mol ∴ Energy of activation for backward reaction = Ea - △ H=85-20=65 kJ mol-1