The concept of chemical equilibrium is very important. Which one of the following statements is the most correct way to think about equilibrium? (a) If a system is at equilibrium, nothing is happening. (b) If a system is at equilibrium, the rate of the forward reaction is equal to the rate of the back reaction. (c) If a system is at equilibrium, the product concentration is changing over time.

Key Concepts

Chemical Equilibrium

Chemical equilibrium occurs in a reversible reaction when the rates of the forward and reverse reactions are equal, resulting in constant concentrations of reactants and products over time. This state does not imply that the reactions have stopped; rather, they continue to occur at equal rates.

Dynamic Nature of Equilibrium

Equilibrium is dynamic, meaning that even though the concentrations of reactants and products remain constant, the individual molecules are still reacting. This ongoing process is crucial for understanding that equilibrium is not a static state but a balance of continuous activity.

Equilibrium Constant

The equilibrium constant (K) quantifies the ratio of product concentrations to reactant concentrations at equilibrium, each raised to the power of their coefficients in the balanced equation. This constant provides insight into the position of equilibrium and the extent of the reaction, indicating whether products or reactants are favored.