Entropy change is intricately linked to the reversibility of chemical reactions. Reversible reactions typically exhibit an entropy change that approaches zero.

To elaborate, entropy serves as a quantitative measure of the disorder or randomness within a system. For a chemical reaction, the change in entropy, denoted as $\Delta S$, represents the difference in entropy between the products and the reactants. If the entropy of the products is greater than that of the reactants, the entropy change is positive, signifying an increase in disorder. Conversely, if the products have a lower entropy than the reactants, the entropy change is negative, indicating a decrease in disorder.

Reversible reactions are characterized by their ability to proceed in both forward and reverse directions. At equilibrium, the rates of the forward and reverse reactions are equal, resulting in constant concentrations of both reactants and products. In this state, the system achieves maximum disorder, or maximum entropy.

According to the second law of thermodynamics, the total entropy of an isolated system can never decrease over time; it remains constant only when all processes are reversible. For a reaction to be classified as reversible, the entropy change must be nearly zero. A significant positive entropy change suggests that the reaction predominantly favors the forward direction, while a substantial negative entropy change indicates a strong preference for the reverse direction. In either case, the reaction loses its reversibility.

In reality, however, no reaction is perfectly reversible. Some energy is invariably lost to the surroundings as heat, leading to an increase in the entropy of the surroundings. Consequently, the entropy change for a reversible reaction is close to zero, but never exactly zero. The concept of entropy change and its correlation with reaction reversibility is a fundamental principle of thermodynamics, essential for understanding a wide array of chemical reactions and processes.