Below are the potential energy profiles for three reactions. Which of the following statements is true?

• A. The activation energy of reaction 3 is thrice the activation energy of reaction 1.
• B. For reaction 2, ΔH_rxn = –65 kJ/mol.
• C. The activation energy of the reverse reaction for reaction 3 is E_a2 = +15 kJ/mol.
• D. The more exothermic the reaction, the faster the reaction would be.
• E. Exothermic reactions are always faster than endothermic reactions.

Answer: (C)