0653.C6.3.04 — Identify oxidation and reduction in redox reactions. (Oxidation number limited to its use to name ions, e.g. iron(II), iron(III), copper(II): past paper questions

Real questions on 0653.c6.3.04 — identify oxidation and reduction in redox reactions. (oxidation number limited to its use to name ions, e.g. iron(ii), iron(iii), copper(ii)

The newest 5 of 5 written questions. Open one to see it on the real paper.

1. 0653/01 · Specimen 2025 · Q27[1]

   Which words complete gaps P, Q and R?

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2. 0653/33 · October/November 2023 · Q2a(i)[1]

   State the name of the gas produced in this investigation.

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3. 0653/43 · October/November 2021 · Q5c[2]

   The reaction between aluminium and iron( III ) oxide is a redox reaction. Name the oxidising agent in this reaction. Explain your answer. oxidising agent explanation

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4. 0653/42 · February/March 2021 · Q5b(iii)[3]

   Complete the sentences below. The substance that is oxidised in Equation 1 is . The substance that is reduced in Equation 2 is . The substance that is oxidised in Equation 3 is , and the substance that is reduced in Equation 3 is .

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5. 0653/42 · February/March 2020 · Q5b(i)[1]

   The word equation for this reaction is shown. copper oxide + carbon copper + carbon dioxide State whether copper oxide is oxidised or reduced in this reaction. Explain your answer.

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What examiners said

There were several gases suggested by candidates for this question. Hydrogen, the correct answer, was chosen by some candidates. Other responses included carbon dioxide and chlorine.

— Examiner report, October/November 2023, 0653/33 Q2(a)(i) (Cambridge)

Generally, candidates found this question challenging. Many candidates incorrectly stated that iron instead of iron oxide is the oxidising agent. Other incorrect answers included oxygen and aluminium as the oxidising agent. Candidates need to know that the oxidising agent oxidises the aluminium during a redox reaction.

— Examiner report, October/November 2021, 0653/43 Q5(c) (Cambridge)

Some candidates gained full credit. At least partial credit was awarded to most candidates because they identified the substance which was oxidised in equation 1. Common mistakes in the second part included carbon and oxygen. Common mistakes in the third part included reversal of carbon monoxide and iron oxide and giving iron rather than iron oxide.

— Examiner report, February/March 2021, 0653/42 Q5(b)(iii) (Cambridge)