O-LevelChemistryRates of Reaction5070/11 · May/June 2025 · Q171 Mark

The diagram shows apparatus used to investigate two different reactions that produce gases. The reactants for each experiment are mixed and the mass of flask plus contents for each experiment is recorded every 30 seconds. A graph of the mass against time is drawn. In experiment 1, solid X is calcium carbonate. In experiment 2, solid X is magnesium. Which graph is correct?

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.

ADiagram A

BDiagram B

CDiagram C

DDiagram D

✓ Correct answer

C: Diagram C

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Topic: Rates of Reaction, O-Level Chemistry (syllabus 5070). Multiple choice, 1 mark.
Source: O-Level Chemistry, May/June 2025 Paper 1 Variant 1, question 17.

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