1. A catalyst decreases the activation energy of a particular exothermic reaction by 50 kJ/mol, to 42 kJ/mol. Assuming that the mechanism has only one step, and that the products are 96 kJ lower in energy than the reactants, sketch approximate energy-level diagrams for the catalyzed and uncatalyzed reactions. What is the activation energy for the uncatalyzed reverse reaction?

2. For a second-order reaction, the initial reactant concentration, [A]o, is 0.83 M. After 17.9 s, the concentration is 0.60 M. What is [A] after 36 s?