Which of the following will INCREASE the rate of a reaction between solid calcium carbonate and dilute hydrochloric acid?
Launching your learning experience…
Exam Season Offer 🎯 Sign up today & get 15% OFF on Yearly Plan
Practise IGCSE 0620 questions in the style of recent Extended past papers, organised by syllabus subtopic. Each set comes with an examiner-style mark scheme and a downloadable worksheet.
Everything students ask about Cambridge IGCSE 0620 Rate of reaction Topical Past Papers.
Top questions students ask on this sub-topic
These Rate of reaction Topical Past Paper Questions are written in the style of recent Cambridge IGCSE Chemistry 0620 Extended papers and grouped by the Chemical reactions (C6.2) section of the 2025–2027 syllabus. Use them to revise the exact skills examiners test in this part of the course.
Each question is graded Easy → Medium → Hard, plus an A★ Challenge for top-grade preparation. Tap a question to mark your own answer, then unlock the examiner-style mark scheme with model solutions and examiner tips. A printable Topical Past Papers worksheet is included so you can practise offline.
Describe practical methods of investigating the rate of reaction (gas collection, mass loss, change in colour). Explain how concentration, surface area, temperature and catalysts affect rate using collision theory. Interpret rate graphs.
Which of the following will INCREASE the rate of a reaction between solid calcium carbonate and dilute hydrochloric acid?
A student investigates the effect of surface area on the rate of reaction between magnesium ribbon and dilute hydrochloric acid.
Predict what would happen to the rate of reaction if the magnesium ribbon was cut into very small pieces instead of being used as one long strip.
[1 mark]Briefly explain your answer in terms of particle collisions.
[1 mark]Which of the following best explains why a higher temperature increases the rate of a reaction?
A student measures the volume of carbon dioxide gas produced over time when marble chips (CaCO₃) react with dilute hydrochloric acid. The graph of volume of CO₂ against time is initially steep, then gradually levels off, and finally becomes flat.
Explain why the graph is steepest at the beginning of the reaction.
[1 mark]Explain why the gradient gradually decreases as the reaction proceeds.
[1 mark]Explain why the graph eventually becomes a horizontal flat line.
[1 mark]Sketch (in words) how the graph would change if the student repeated the experiment with MORE concentrated acid (same volume), keeping everything else constant.
[1 mark]Which statement about catalysts is correct?
Manganese(IV) oxide (MnO₂) is a catalyst for the decomposition of hydrogen peroxide: 2H₂O₂(aq) → 2H₂O(l) + O₂(g).
Describe how you could investigate whether the MnO₂ is acting as a catalyst (i.e. show that it is not used up).
[2 marks]On an energy profile diagram for this reaction, describe how the curve for the CATALYSED reaction differs from the uncatalysed reaction.
[1 mark]When a catalyst is added to a mixture of nitrogen and hydrogen gas in the Haber process at the same temperature and pressure, the rate of formation of ammonia increases significantly.
Use the Maxwell-Boltzmann idea (the distribution of molecular energies) to explain WHY a catalyst increases the reaction rate.
[2 marks]The Haber process is run at about 450 °C, not at room temperature. Suggest why a higher temperature is used, even though it slightly disfavours the equilibrium yield of ammonia.
[1 mark]Doubling the concentration of a reactant doubles the rate of the reaction at constant temperature. If the temperature is then raised so that the rate at the new (doubled) concentration becomes 8 times the original rate, by approximately what factor has the temperature increase changed the rate independently?