The kc is a representation of how fast the reaction proceeds to their products when it has achieved equilibrium. The activation energy for the forward and the one for the reverse
reaction are similar because they attained chemical equilibrium. A chemical
equilibrium happens when both of the reactant and products achieve the same
concentration. An example is the process of melting and freezing. Melting and freezing for a given
substance occurs at the same temperature. Because the temperature at which the
solid starts to melt is also the temperature at which the liquid starts to
freeze. They are at chemical equilibrium.