0654.C5.1.05 — Define activation energy, Ea, as the minimum energy that colliding particles must have to react: past paper questions
Real questions on 0654.c5.1.05 — define activation energy, ea, as the minimum energy that colliding particles must have to react
The newest 5 of 5 written questions. Open one to see it on the real paper.
- 0973/41 · May/June 2026 · Q6a[2]
The reaction between chlorine, CL, and sodium iodide, NaI, has a low activation energy. State what is meant by activation energy.
See it on the paper → - 0973/41 · October/November 2025 · Q7b(iv)[2]
The enthalpy change, ΔH, for the reaction is negative. Fig. 7.1 shows two reaction pathway diagrams, A and B. A B products reactants energy energy products reactants progress of reaction progress of reaction Fig. 7.1 State which of these reaction pathway diagrams, A or B, represents the energy change for this reaction....
See it on the paper → - 0973/42 · May/June 2023 · Q5b(ii)[1]
Draw an arrow on Fig. 5.1 to show the activation energy of the reaction. Label your arrow B.
See it on the paper → - 0973/41 · October/November 2019 · Q8b(iii)[1]
A catalyst works by reducing activation energy in a reaction. Explain what is meant by the activation energy.
See it on the paper → - 0973/42 · May/June 2019 · Q8b(i)[1]
Use the diagram to explain why the reactant mixture must be heated before the reaction starts.
See it on the paper →
What examiners said
The activation energy was generally labelled successfully. As with part (b)(i), some imprecise arrows were seen.
— Examiner report, May/June 2023, 0973/42 Q5(b)(ii) (Cambridge)
Many candidates had the right idea but found it challenging to express it clearly. Some candidates correctly described the heat as supplying the necessary activation energy. A number of candidates inaccurately described the heat increasing the activation energy or referred to speeding up of the reactions.
— Examiner report, May/June 2019, 0973/42 Q8(b)(i) (Cambridge)
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