When a reversible chemical reaction is at equilibrium,
A)the rate of the reaction in one direction is equal to the rate in the reverse direction.
B)the concentration of the reactants is equal to the concentration of the products.
C)both the forward and reverse reactions stop occurring.
D)the supply of reactants has become exhausted,so the forward reaction ceases and the rate of the reverse reaction increases.
E)catalysts no longer influence either the forward or reverse reaction rates.

Question

Quizplus · Accepted Answer

At equilibrium, the rates of the forward and reverse reactions become equal, which means that there are equal numbers of molecules or ions forming products as there are breaking down to form reactants. However, this does not mean that the concentrations of the reactants and products are equal, as their amounts may vary depending on the reaction stoichiometry and the initial conditions. Furthermore, the reactions continue to occur, but in a dynamic balance where the concentrations of the species involved do not change over time. Lastly, the presence of a catalyst can still affect the rate of both the forward and reverse reactions, even at equilibrium.

When a Reversible Chemical Reaction Is at Equilibrium