5.6 Reaction Energy Profile

Reactants climb to the transition state (peak), then fall to products. Ea = peak − reactants. ΔH = products − reactants.

Ea for the reverse reaction = peak − products.

Products below reactants = exothermic.

Worked example: Reactants 50 kJ, peak 120, products 20 → Ea = 70, ΔH = −30, Ea(rev) = 100.