Which of the following statements is correet for a reaction at equilibrium?

Step 1: Analyze the question You are asked which statement is true for a reaction at equilibrium. This is about dynamic chemical equilibrium in reversible reactions.

Step 2: The concept In a reversible reaction, e.g. N₂(g) + 3H₂(g) ⇌ 2NH₃(g), the reactants form products (forward reaction), and the products also break back down into reactants (backward reaction).

At equilibrium:

• The rate of the forward reaction = the rate of the backward reaction.
• The reaction has not stopped. It is dynamic, meaning both reactions keep going at the same speed.
• Because the rates are equal, the concentrations of reactants and products stay constant (not necessarily equal).

Step 3: Check each option

• A. All reactions cease to occur. Wrong. Both forward and backward reactions continue; equilibrium is dynamic, not static.
• B. The reaction has gone to completion. Wrong. At equilibrium, reactants and products coexist. Completion would mean no reactants are left.
• C. The rates of the forward and backward reactions are equal. Correct. This is the defining condition of equilibrium.
• D. The amount of product equals the amount of reactants. Wrong. The amounts are constant, but they are usually not equal. Their ratio is determined by the equilibrium constant, Kc.

Step 4: Answer

Exam tip: Remember "Dynamic, not dead". At equilibrium, nothing appears to change, but both reactions are still happening at equal rates. Constant does not mean equal. WASSCE and JAMB often test this distinction.