Cambridge IGCSE Chemistry can feel like two subjects in one: ideas you must understand, and questions you must learn to answer under time pressure. This guide pulls the syllabus into a clear map, breaks the big topics into smaller revision chunks, and gives you a practical way to study so your marks move, not just your notes.

Syllabus at a glance

Most students sit three papers. If you are entered for Core, you take Paper 1 (MCQ), Paper 3 (theory), and either Paper 5 (practical) or Paper 6 (alternative to practical). If you are entered for Extended, you take Paper 2 (MCQ), Paper 4 (theory), and Paper 5 or Paper 6. Across the qualification, the assessment objectives weight knowledge and understanding at 50%, problem-solving at 30%, and practical skills at 20%, so your revision has to cover all three, not only content recall.

The 12 topic areas you must cover

The Cambridge content overview is organised into 12 areas: states of matter; atoms, elements and compounds; stoichiometry; electrochemistry; chemical energetics; chemical reactions; acids, bases and salts; the Periodic Table; metals; chemistry of the environment; organic chemistry; experimental techniques and chemical analysis. Build your revision plan around these headings, because past-paper questions keep returning to them.

How to study each topic: a repeatable method

Use a simple three-pass routine for every chapter.

Pass 1: Understand the story (20–30 minutes). Start with a one-page summary in your own words. Focus on the “why”: particle model links to diffusion, bonding links to properties, and equilibrium links to yield. If you cannot explain it out loud, you do not own it yet.

Pass 2: Drill the skills (30–45 minutes). Chemistry rewards method. For calculations, write a standard layout you will reuse: write the equation, balance it, list what is given, convert units, then solve. For definitions, learn the mark-scheme phrasing, then practise writing it in one clean sentence.

Pass 3: Apply under exam conditions (30–60 minutes). Do timed past-paper questions by topic, then switch to mixed questions. Mark with the official scheme and rewrite only what you missed: the correct equation, the missing key word, or the unit.

Topic-by-topic focus points

States of matter & separation. Learn the particle model, changes of state, and the core separation methods (filtration, crystallisation, distillation, chromatography). Pair every method with the property it uses.

Atoms, bonding, and structure. Know atomic structure, isotopes, electron arrangements, ions, and the differences between ionic, covalent, metallic, and giant structures. Link structure to melting point, conductivity, and solubility.

Stoichiometry. This is the marks engine. Master moles, molar mass, gas volume, concentration, percentage yield, and limiting reagents. Practise until your set-up is automatic.

Electrochemistry. Understand redox, oxidation numbers, electrolysis, and why products form at electrodes. Practise half-equations and ionic equations.

Energetics and rates. Learn exothermic vs endothermic, energy level diagrams, and activation energy. For rates, know collision theory, catalysts, and how to interpret graphs.

Reactions, acids, and salts. Secure patterns: precipitation, neutralisation, and metal reactivity. Learn preparation of salts and the qualitative tests list (ions and gases).

Periodic Table and metals. Learn trends, Group I and Group VII patterns, transition metal properties, and key extraction ideas (reactivity series, blast furnace basics, electrolysis for aluminium).

Environment and organic. Practise core processes (air and water pollutants, Haber process, cracking, polymerisation, fermentation, fuels). In organic, get confident with naming, functional groups, and reaction types.

Practical and Paper 6: free marks if you train it

Paper 5/6 tests planning, variables, accuracy, graphing, and analysis rather than memorised content. Practise recording results in neat tables with units, choosing sensible apparatus, identifying sources of error, and suggesting realistic improvements. Learn the qualitative analysis tests for gases and ions and keep them on one revision sheet.

Create a mini toolkit for every session: a calculator, a periodic table, and a short checklist. Your checklist can include: balance the equation, show units, write state symbols when asked, and round to the required significant figures. Before the exam, memorise the common flame colours and gas tests, then practise recognising them from descriptions. Stick it above your desk.

Past-paper strategy that actually works

Do papers in this order: topical questions first, then full papers, then the newest series last. After each paper, create a “mistake log” with three columns: the topic, the reason you lost marks, and the fix you will practise. Most grade jumps come from repeating the same fix across a week.

A simple 4-week plan

Week 1: Stoichiometry, acids/salts, bonding.
Week 2: electrolysis, Periodic Table, metals.
Week 3: energetics, rates, organic.
Week 4: environment, analysis/tests, mixed papers daily.

Keep each study session tight: one concept, one skill set, one timed set of questions. If you do that consistently, Chemistry stops being a memory game and starts feeling like a system you can score in.