What does it mean when the rates of forward and reverse reactions are equal in a closed system?

When the rates of forward and reverse reactions are equal in a closed system, it indicates that the system has reached dynamic equilibrium. At this point, the concentration of reactants and products remains constant over time because the rate at which reactants are converted to products is precisely balanced by the rate at which products convert back into reactants. This does not mean that the reactions have stopped occurring; rather, the ongoing processes of transformation continue to happen, but their effects cancel each other out, leading to stable concentrations.

This concept is central to understanding chemical equilibria, where no net change is observed in the concentration of substances, although molecular interactions are still actively taking place. Therefore, the correct interpretation of equal rates of forward and reverse reactions is that the system is in a dynamic equilibrium state.