O-Level Chemistry Qualitative Analysis Toolkit (Paper 3)

TL;DR
SEAB’s 2026 O-Level Chemistry syllabus (6092) keeps qualitative analysis (QA) at the heart of Paper 3, complete with supplied QA notes and 15 % Planning marks.
Score MMO and PDO by sequencing confirmatory tests logically, writing concise observation phrases, and tabulating results with clear headings.
ACE commentary should justify inferences, reconcile ambiguous tests, and recommend refinements grounded in syllabus safety and analytical guidance.

1 | Syllabus signals you must internalise

• Section 4 of the 2026 O-Level Chemistry syllabus specifies that Paper 3 assesses Planning, MMO, PDO, and ACE via tasks such as qualitative analysis, titrations, and investigative work. QA remains a staple, with candidates expected to handle unknown salts, gases, and solutions efficiently.
• The QA notes appended in the examination booklet list reagents, observations, and inference pathways; SEAB expects familiarity so you can choose confirmatory steps quickly (SEAB 2026 syllabus).
• Planning carries about 15 % of Paper 3 marks, so your method outline must show a logical flow: preliminary tests → confirmatory evidence → safety considerations.

2 | Planning workflow before the stopwatch starts

1. State the aim: “Identify the cations/anions present in unknown solution X.”
2. Outline screening tests: Flame test, pH, gas evolution with dilute acid, odor checks (wafting only).
3. Plan confirmatory sequence: E.g. Add aqueous sodium hydroxide → observe precipitate colour/solubility → add aqueous ammonia for metal cation differentiation.
4. Controls and safety: Note the need for clean test tubes, freshly prepared reagents, and proper disposal (heavy-metal waste).
5. Data recording: Pre-design a table with columns for reagent, observation, and inference; align with PDO expectations in the syllabus.

3 | Observation language cheat sheet