IGCSE Combined Science 0653 · Chemistry · 119

0653.C12.4.01 — Describe tests to identify the anions: (a). carbonate, CO32–, by reaction with dilute acid and then testing for carbon dioxide gas (b). chlo: past paper questions

6 real questionsasked in 3 of the last 10 exam series2022–2025usually: Identify, State, Describe

Real questions on 0653.c12.4.01 — describe tests to identify the anions: (a). carbonate, co32–, by reaction with dilute acid and then testing for carbon dioxide gas (b). chlo

The newest 6 of 6 written questions. Open one to see it on the real paper.

0653/61 · May/June 2025 · Q3b(i)[1]
Identify the anion (negative ion) shown to be present in aqueous H.
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0653/62 · October/November 2023 · Q2e(i)[1]
State the name of the anion (negative ion) in the filtrate.
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0653/62 · October/November 2023 · Q2e(ii)[1]
State the name of the cation (positive ion) in the filtrate.
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0653/63 · October/November 2023 · Q3b(ii)[1]
Tick (3) the name of the anion (negative ion) present in H. carbonate chloride nitrate sulfate
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0653/62 · May/June 2023 · Q3b(ii)[1]
Identify the anion (negative ion) present in solid H.
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0653/33 · October/November 2022 · Q5a(v)[2]
Describe a chemical test for chloride ions and state the positive result. test result
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What examiners said

Most candidates used the Qualitative Analysis notes to correctly identify chloride ions.
— Examiner report, May/June 2025, 0653/61 Q3(b)(i) (Cambridge)

A number of candidates correctly identified iron(II) although some omitted the (II).
— Examiner report, October/November 2023, 0653/62 Q2(e)(ii) (Cambridge)

Most candidates were able to identify the anion as carbonate.
— Examiner report, October/November 2023, 0653/63 Q3(b)(ii) (Cambridge)

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Practise 0653.c12.4.01 — describe tests to identify the anions: (a). carbonate, co32–, by reaction with dilute acid and then testing for carbon dioxide gas (b). chlo

In the syllabus

119 0653.C12.4.01 — Describe tests to identify the anions: (a). carbonate, CO32–, by reaction with dilute acid and then testing for carbon dioxide gas (b). chlo

Describe tests to identify the anions: (a). carbonate, CO32–, by reaction with dilute acid and then testing for carbon dioxide gas (b). chloride, Cl –, bromide, Br –, and iodide, I–, by acidifying with dilute nitric acid then adding aqueous silver nitrate (c). sulfate, SO42–, by acidifying with dilute nitric acid and then adding aqueous barium nitrate
Describe tests using aqueous sodium hydroxide and aqueous ammonia to identify the aqueous cations: (a). ammonium, NH4+ (b). calcium, Ca2+ (c).copper(II), Cu2+ (d).iron(II), Fe2+ (e).iron(III), Fe3+ (f). zinc, Zn2+ (formulas of complex ions are not required)
Describe tests to identify the gases: (a) . ammonia, NH3, using damp red litmus paper (b) . carbon dioxide, CO2, using limewater (c) . chlorine, Cl 2, using damp litmus paper (d) . hydrogen, H2, using a lighted splint (e) . oxygen, O2, using a glowing splint
Describe the use of a flame test to identify the cations: (a) . lithium, Li+ (b) . sodium, Na+ (c) . potassium, K+ (d) . copper(II), Cu2+

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