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JAMB Chemistry 1991 Question 27

Question 27

Rates of Reaction

Manganese (IV) oxide is known to hasten the decomposition of hydrogen peroxide. Its main action is to

  1. A.increase the surface area of the reactants
  2. B.increase the concentration of the reactants
  3. C.lower the activation energy for the reaction
  4. D.lower the heat of reaction, ΔH, for the reaction
Show the answer and explanation

Answer: C (lower the activation energy for the reaction)

Explanation

MnO2 is a catalyst. A catalyst gives the reaction a route with lower activation energy; it does not change ΔH.