Qualitative analysis practice

Tests for cations, anions and gases, in the words of your board’s notes. Type what you would see, or name the ion, and each box is marked with a reason.

Notes
Kind of problem

Set

Rules and marking
    The notes

      Answers are saved on this device as you type.

      How it works

      Pick the notes you will have in the exam. Each preset uses only its own board’s table and wording: the SEC and O-Level Notes for Qualitative Analysis, the IGCSE 0620 notes (with chromium(III), bromide, sulfite and flame tests), or the tests in the AQA specification. A new set draws different salts each time.

      Five kinds of problem: write the observations for a salt, name the ion or gas from what was seen, complete a results table and name the unknown, answer an SEC-style flowchart (not for AQA, which sets none), and choose a test that tells two solutions apart.

      Observations are read for the colour of the ppt., what happens in excess, effervescence and the gas test, so ppt. or precipitate and xs or excess both count. Each slip examiners report gets a hint of its own.

      An example from set TEST42

      In set TEST42, aqueous sodium hydroxide gives X a white ppt., soluble in excess giving a colourless solution, so the cation is aluminium or zinc. Aqueous ammonia gives a white ppt. that also dissolves in excess, which only zinc does, so the cation is zinc, Zn²⁺. Acidified aqueous barium nitrate gives a white ppt., so the anion is sulfate, SO₄²⁻, and acidified aqueous silver nitrate gives no ppt. The missing observation, test 4 with dilute hydrochloric acid, is no visible change: a sulfate does not fizz with acid. X is zinc sulfate, ZnSO₄. Open set TEST42

      What examiners mark down

      SEAB does not publish examiner reports. Cambridge’s IGCSE 0620 reports for 2023 and 2024 name these slips:

      • “cloudy” where a precipitate has formed, and “a gas is given off” in place of effervescence;
      • “clear” for colourless, which the November 2024 report says are not the same;
      • white for the cream ppt. of silver bromide, and blue-green or grey-green for the green ppt. of iron(II) (November 2024);
      • iron with no oxidation state, and formulae with the wrong ionic charge (June 2023);
      • chlorine for chloride and ammonia for ammonium (June 2024), and bromine ion for bromide (November 2024);
      • “no change” when potassium manganate(VII) keeps its colour, and extra observations that are wrong (June 2024);
      • orange for calcium’s orange-red flame, which is accepted only for sodium (November 2023 and 2024).

      Questions

      What do you write for an observation in qualitative analysis?

      Write what you see, not what it means: the colour of a precipitate (ppt.), whether it dissolves in excess and the colour of the solution it gives, or effervescence and the result of the gas test. Cambridge’s examiners expect the word precipitate, and they do not accept “a gas is given off” as an observation: write effervescence, fizzing or bubbles.

      How do you tell aluminium ions from zinc ions?

      Both give a white ppt. with aqueous sodium hydroxide that dissolves in excess, giving a colourless solution. Add aqueous ammonia instead: the white ppt. of zinc dissolves in excess, and the white ppt. of aluminium does not.

      Is the notes table given in the exam?

      For SEC Chemistry K324, yes: the syllabus says a copy of the Notes for Qualitative Analysis is printed as part of the practical paper. The IGCSE 0620 syllabus says the notes are provided for Paper 5 and Paper 6. Learn the wording anyway, because the marks go to the words the notes use.

      Which syllabuses does this follow?

      Three presets, each built only from its own board’s published table: SEAB SEC Chemistry K324 (2027), whose notes match O-Level 6092; Cambridge IGCSE Chemistry 0620 (2026 to 2028), which adds chromium(III), bromide, sulfite and flame tests; and AQA GCSE Chemistry 8462, which uses sodium hydroxide, flame tests, silver nitrate, barium chloride and four gas tests.

      Sources, checked 29 October 2026: SEAB SEC Chemistry K324 syllabus for 2027 (PDF), Notes for Qualitative Analysis; Singapore-Cambridge O-Level Chemistry 6092 syllabus for 2026 (PDF); Cambridge IGCSE Chemistry 0620 syllabus for 2026 to 2028 (PDF), Notes for use in qualitative analysis; AQA GCSE Chemistry 8462 specification, version 1.2, 4.8.2 and 4.8.3. Cambridge IGCSE Chemistry 0620 Principal Examiner Reports for Teachers, June 2023, November 2023, June 2024 and November 2024, from the Cambridge School Support Hub.