Catalysts and Reaction Rate

[Jasmin Gonzalez]

How do we distinguish and differentiate substances if they are catalysts and those that participate in a reaction as reactants or intermediates? Also, how does a catalyst increase the rate of a reaction and lower the activation energy of the transition state?

[806020644 3I]

A catalyst will be consumed and then produced in a subsequent step, while an intermediate will be produced and then consumed. A catalyst lowers the activation energy.

[kelsi husted 2i]

Hi!
Just to add onto this, catalysts can be distinguished from reactants or intermediates by their prsence in the reaction mechanism but unchanged in quantity at the end. Catalysts increase reaction rates by providing an alternative pathway with a lower activation energy, facilitating the formation of the transition state and subsequently accelerating the reaction. This is why we see that k is faster for the forward and reverse reactions. An important thing to remember with this as well is that they don't change the equilibrium concentrations either.
Hope this helps!