13.78b Mechanism will probably change, thus k will probably change. No effect on k. 13.81a Catalyst changes the mechanism to one with lower activation energy. 13.81b Catalyst changes the mechanism. 13.81c Catalyst does not change the reaction enthalpy.
Catalysts increase the rate of the forward reaction.
Catalysts increase the rate of the reverse reaction. Increases the rate. 13.82b Decreases the rate. Decreases the rate. Increases the rate.