O-LevelChemistryRates of Reaction5070/12 · May/June 2019 · Q191 Mark

Hydrogen peroxide decomposes slowly at room temperature. 2H2O2(aq) → 2H2O(l) + O2(g) The reaction can be catalysed by adding manganese(IV) oxide. The diagram shows the apparatus that can be used to monitor the rate of this reaction. Which statement is correct when a catalyst is added to the aqueous hydrogen peroxide?

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.

AThe catalyst increases the activation energy for the reaction.

BThe catalyst is used up during the reaction.

CThe gas syringe fills up more quickly when the catalyst is added.

DThe total amount of oxygen produced increases when the catalyst is added.

✓ Correct answer

C: The gas syringe fills up more quickly when the catalyst is added.

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Topic: Rates of Reaction, O-Level Chemistry (syllabus 5070). Multiple choice, 1 mark.
Source: O-Level Chemistry, May/June 2019 Paper 1 Variant 2, question 19.

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