activation energy by a variety of ways: They may, for example, increase the frequency of collision
between the reactants, or change the relative orientation of the reactants making a higher
percentage of collisions effective. The following figure compares the energy profiles of catalyzed
and uncatalyzed reactions.
The energy barrier for the catalyzed reaction is much lower than the energy barrier for the
uncatalyzed reaction. Note that the rates of both the forward and the reverse reactions are
increased by catalysis, since Ea of the forward and reverse reactions are lowered by the same
amount. Therefore, the presence of a catalyst causes the reaction to proceed more quickly toward
equilibrium, without changing the position of the equilibrium, i.e., without changing the value of
the equilibrium constant.