0654.C7.2.01 — Classify oxides as either acidic, including SO2 and CO2, or basic, including CuO and CaO, related to metallic and non-metallic character: past paper questions

Real questions on 0654.c7.2.01 — classify oxides as either acidic, including so2 and co2, or basic, including cuo and cao, related to metallic and non-metallic character

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

1. 0654/41 · May/June 2025 · Q6d[1]

   State the type of oxide formed when carbon, a non-metal, reacts with oxygen to produce carbon dioxide, CO 2 .

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2. 0654/12 · May/June 2023 · Q21[1]

   Which row describes properties of these oxides?

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3. 0654/11 · May/June 2019 · Q19[1]

   Which row identifies the types of oxides?

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4. 0654/11 · May/June 2019 · Q25[1]

   Which two statements about calcium carbonate are correct?

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5. 0654/21 · May/June 2019 · Q19[1]

   Which row classifies these oxides?

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What examiners said

Most candidates did not identify that an acidic oxide would be formed. There was a wide variety of incorrect answers given. This concept was not well understood.

— Examiner report, May/June 2025, 0654/41 Q6(d) (Cambridge)

Some of the stronger candidates chose the incorrect A rather than the correct answer, D. In the incorrect A, all four of the oxides were in the wrong columns. Candidates are required to know that metals form basic oxides and that non-metals form acidic oxides.

— Examiner report, May/June 2019, 0654/11 Q19 (Cambridge)

More candidates, particularly some of the stronger candidates, chose the incorrect A than the correct answer, B. They needed to know that calcium carbonate neutralises acidic industrial waste, they confused its role in lowering of soil acidity with lowering soil pH.

— Examiner report, May/June 2019, 0654/11 Q25 (Cambridge)