0653.C10.1.01 — Describe chemical tests for the presence of water using anhydrous cobalt(II) chloride and anhydrous copper(II) sulfate: past paper questions
Real questions on 0653.c10.1.01 — describe chemical tests for the presence of water using anhydrous cobalt(ii) chloride and anhydrous copper(ii) sulfate
The newest 7 of 7 written questions. Open one to see it on the real paper.
- 0653/32 · May/June 2025 · Q5e[1]
Aluminium is extracted by electrolysis. Name the main ore of aluminium.
See it on the paper → - 0653/32 · May/June 2025 · Q6c[1]
Anhydrous cobalt( II ) chloride is used to test for water. State the colour observed for a positive result.
See it on the paper → - 0653/61 · May/June 2024 · Q2d[1]
Describe the test for carbon dioxide. Include the observation for a positive result.
See it on the paper → - 0653/42 · February/March 2024 · Q2a(iv)[1]
is extracted from bauxite by electrolysis.
See it on the paper → - 0653/12 · October/November 2022 · Q24[1]
Which row identifies the methods used to extract copper and aluminium from their ores?
See it on the paper → - 0653/22 · May/June 2022 · Q24[1]
Which colour change is seen when water is added to anhydrous cobalt(II) chloride?
See it on the paper → - 0653/43 · May/June 2022 · Q5d(i)[2]
The student does a test which shows that the colourless liquid contains water. Describe a chemical test for water. State the colour change observed. test colour change from to
See it on the paper →
What examiners said
Some candidates knew bauxite, the main ore containing aluminium. Incorrect answers included aluminium, iron or other metallic elements. It was clear that many candidates did not understand what an ore is. An ore is a naturally occurring rock that contains metals or metal compounds.
— Examiner report, May/June 2025, 0653/32 Q5(e) (Cambridge)
One test for water is that anhydrous cobalt(II) chloride paper changes from blue to pink. Only a few candidates knew this positive result. All colours were stated.
— Examiner report, May/June 2025, 0653/32 Q6(c) (Cambridge)
Candidates chose the incorrect D more often than the correct answer, C. Candidates are required to know the methods of extraction of copper and of aluminium from their ores.
— Examiner report, October/November 2022, 0653/12 Q24 (Cambridge)
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