Question

which of the following statements are always true for a reaction at equilibrium? i. the rate of the forward and reverse reactions is equal. ii. the concentrations of the reactants and the products remain constant. iii. the amount of reactants is equal to the amount of products. answer: a. i and ii b. i and iii c. ii and iii d. i, ii and iii

Explanation:

• I: At equilibrium, the rate of the forward reaction is equal to the rate of the reverse reaction. This is the definition of chemical - equilibrium.
• II: The concentrations of reactants and products remain constant at equilibrium because the forward and reverse reaction rates are equal, but they are not necessarily equal to each other.
• III: The amount of reactants is not necessarily equal to the amount of products at equilibrium. The equilibrium position is determined by the equilibrium constant and initial concentrations.

Answer:

A. I and II