For a reaction 2A + B ⇌ C + D the active mass of B is kept constant and that of A is tripled. It is observed that the rate of reaction:
Correct answer: D. Increases nine times
- A. Decreases three times
- B. Decreases nine times
- C. Increases six times
- D. Increases nine times
Explanation
By the law of mass action, the rate ∝ (active mass of A)² × (active mass of B). Since B is constant and A is tripled, the rate becomes 3² = 9 times larger. Therefore, the reaction rate increases nine times.
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About Chemical Equilibrium
Reversible reactions reach dynamic equilibrium when forward and reverse rates become equal, and Le Chatelier's principle predicts the effect of changing concentration, pressure or temperature. The chapter also covers solubility product, the common ion effect, buffer action and the conditions used in Haber's process, with equilibrium shifts distinguished from changes in the equilibrium constant.
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