In equilibrium reactions, what occurs to the concentrations of reactants and products?

In an equilibrium reaction, the system reaches a state where the rate of the forward reaction equals the rate of the reverse reaction. At this point, the concentrations of both reactants and products become constant over time. This does not mean that the reactions have stopped occurring; instead, the dynamic nature of the system allows for continuous conversion between reactants and products, maintaining constant concentrations.

When the system is at equilibrium, although individual molecules are still reacting, there are no net changes in the concentrations of reactants or products. This stability is characteristic of equilibrium systems, making the understanding of this concept vital in predicting the behavior of chemical reactions in various circumstances.