IGCSE Chemistry revision: a plan for every paper
TutorAura guide · Updated
Cambridge IGCSE Chemistry (0620) has twelve units and three papers per candidate. The topics that most often separate grades are stoichiometry (moles), equations and chemical tests. Secure those, then work through the rest of the IGCSE Chemistry syllabus topic by topic.
Key takeaways
- Secure moles and reacting masses early: later topics depend on them.
- Practise balancing and ionic equations regularly.
- Learn chemical tests with their results together.
- Use timed past paper practice for every paper.
The papers and how to prepare
| Paper | What helps |
|---|---|
| Multiple choice (1 or 2) | Work through every question; cross out wrong options; don't spend more than about a minute on one |
| Theory (3 or 4) | Read the command word; show working in calculations; use precise scientific terms |
| Practical (5) or Alternative to Practical (6) | Know how to read instruments, record results in tables, plot graphs and suggest improvements |
Multiple choice is worth 30%, theory 50% and the practical paper 20%.
Stoichiometry first
Moles connect formulas, masses, concentrations and gas volumes. Make sure you can:
- calculate (relative formula mass);
- convert between mass and moles (moles explained);
- use mole ratios from balanced equations for reacting masses.
Check your working with the moles calculator.
Equations
Write word and symbol equations for reactions as you meet them, with state symbols. Practise balancing until it's quick. Extended candidates also need ionic equations and half-equations for electrolysis.
Tests and observations
Many marks come from describing tests and their results: the test for hydrogen, oxygen, carbon dioxide, ammonia and chlorine, and tests for common cations and anions. Make flashcards with the test on one side and the observation on the other, and say "what you'd see", not just the name of the product.
Explaining properties
Theory questions often ask why a substance behaves as it does. Link structure to properties: ionic lattices and melting points, simple molecules and volatility, delocalised electrons and conductivity. See ionic vs covalent bonding.
A four-week plan before the exams
| Week | Focus |
|---|---|
| 1 | Stoichiometry and equations; red topics from units 1 to 4 |
| 2 | Red topics from units 5 to 12; chemical tests flashcards |
| 3 | Mixed past paper sections; multiple choice under time |
| 4 | Full papers, mistake review and practical skills |
Fit it around your other subjects with the revision timetable generator.
Practical skills
Practical and Alternative to Practical questions test planning and analysis: choosing apparatus, describing a method, recording results in a table, plotting a graph, identifying anomalous results and suggesting improvements. Practise describing titrations, separation techniques and how to prepare a pure, dry sample of a salt in clear numbered steps.
Frequently asked questions
How do I get better at describing observations?
Say what you would see: colour changes, fizzing, a precipitate forming or a solid dissolving, rather than naming the product.
How do I revise organic chemistry?
Make a table of the homologous series with their functional groups, general formulas, reactions and tests, and test yourself on it regularly.
What topics come up most in IGCSE Chemistry?
Every topic can be examined, but stoichiometry, bonding, acids and salts, and organic chemistry appear often and link to other topics.
How do I remember the reactivity series?
Use a mnemonic for the order and practise questions on displacement reactions, which use the series. Writing it out from memory a few times helps it stick.
How do I improve at IGCSE Chemistry calculations?
Use the same method every time: write the equation, find moles, use the ratio, convert back. Practise a few questions daily and check them with worked solutions.
What is the hardest part of IGCSE Chemistry?
Many students find stoichiometry (moles and reacting masses) hardest. Regular practice with a consistent method makes it reliable marks.
How do I remember chemical tests?
Flashcards with the test and its observed result, tested regularly. Practise writing the observation in full.
How should I use past papers for IGCSE Chemistry?
Start with questions by topic, then do full papers under time. Mark them carefully and redo questions you got wrong after a few days.
Sources
- Cambridge IGCSE Chemistry 0620 syllabus for 2026, 2027 and 2028. Cambridge International.
- Improving Students' Learning With Effective Learning Techniques. Psychological Science in the Public Interest (Dunlosky et al., 2013).
Keep reading
Interactive periodic table of elements
All 118 elements with atomic masses, electron configurations, groups and properties.
Cambridge IGCSE Chemistry syllabus (0620) for 2026 to 2028
All twelve units and their topics, the exam papers, and Core vs Extended.
Moles in chemistry explained: formula and examples
Moles = mass ÷ Mr, Avogadro's constant, reacting masses, limiting reactants and concentration.
Relative formula mass (Mr) calculator
Mr for any formula, including brackets and water of crystallisation, with a breakdown table.
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