1. The problem statement, all variables and given/known data For a reaction that is exothermic in the forward direction, can the activation energy Ea(fwd) ever be less than the enthalpy change? 2. Relevant equations Endothermic equation: Ea(rev) = Ea(fwd) - deltarH 3. The attempt at a solution The answer in the book has "yes", but I don't know how this can be true. Since it's an exothermic reaction, deltarH is negative. And as far as I know, the forward activation energy must be positive. Is it possible that the book meant magnitude? If so, then I could understand why they gave that answer.