Cambridge IGCSE Chemistry Syllabus Guide (0620)
Complete breakdown of all 255 learning objectives for the 2023-2025 syllabus, with Core vs Supplement topics and study strategies
The Cambridge IGCSE Chemistry syllabus contains 255 learning objectives across 12 main topics. This guide breaks down exactly what you need to know for Core and Supplement (Extended) tiers.
Chemistry is often described as the "central science" - it connects physics to biology and touches everything from medicine to materials. But that breadth means there's a lot to learn: atomic structure, bonding, reactions, organic chemistry, and more.
The key to success? Understanding the syllabus structure. It shows you exactly what's Core vs Supplement-only, which topics carry the most weight, and where Extended students need to focus on calculations (like moles and titrations). Many students are surprised to discover that organic chemistry alone makes up 20% of the syllabus.
This guide helps you see the full picture - so you can study smarter, not just harder. Ready to practice? Try our IGCSE Chemistry past papers.
First: Know Your Tier - Core vs Extended
Before diving into the syllabus, you must understand the tier system. Cambridge IGCSE Chemistry offers two levels of difficulty, and you need to know which one you're taking.
Core Tier
Papers 1, 3, 5
- 156 learning objectives
- Grades available: C to G
- Foundational concepts
- Qualitative understanding
- Basic calculations
- Descriptive answers
Extended Tier
Papers 2, 4, 6
- 255 learning objectives (all Core + 99 more)
- Grades available: A* to E
- Advanced concepts
- Quantitative analysis
- Complex calculations (moles, titrations)
- Deeper explanations
Important
Your school or exam centre decides which tier you take. If you're aiming for grades A*-B, you must take Extended. Core tier caps at grade C.
Check with your teacher if you're unsure which tier you're registered for.
The 12 Topics: Syllabus Overview
IGCSE Chemistry is organized into 12 main topics covering everything from particle theory to organic chemistry. You'll start with states of matter and build up to understanding atoms and bonding. Then learn about stoichiometry (chemical calculations), electrochemistry, and energy changes. Chemical reactions covers rates and equilibrium. Acids and bases, the Periodic Table, and metals follow. Finally, environmental chemistry, organic chemistry, and experimental techniques complete the syllabus.
Here's how the learning objectives break down across the 12 topics:
| Unit | Topic | Core | Supp | Total | % |
|---|---|---|---|---|---|
| 11 | Organic chemistry | 30 | 21 | 51 | 20% |
| 6 | Chemical reactions | 12 | 21 | 33 | 13% |
| 2 | Atoms, elements and compounds | 18 | 11 | 29 | 11% |
| 9 | Metals | 16 | 7 | 23 | 9% |
| 7 | Acids, bases and salts | 12 | 8 | 20 | 8% |
| 3 | Stoichiometry | 8 | 11 | 19 | 7% |
| 10 | Chemistry of the environment | 15 | 3 | 18 | 7% |
| 12 | Experimental techniques | 16 | 2 | 18 | 7% |
| 8 | The Periodic Table | 13 | 2 | 15 | 6% |
| 4 | Electrochemistry | 8 | 5 | 13 | 5% |
| 1 | States of matter | 5 | 3 | 8 | 3% |
| 5 | Chemical energetics | 3 | 5 | 8 | 3% |
| TOTAL | 156 | 99 | 255 | 100% | |
Supplement-Only Topics
Some topics are heavily Supplement-only - Core students can skip these:
- 3.3 The mole and Avogadro constant - Mostly Supplement (7 of 8 objectives)
- 6.3 Reversible reactions and equilibrium - Mostly Supplement (9 of 11 objectives)
- 2.7 Metallic bonding - Entirely Supplement
Key Insight: Focus on the Big Three
The top 3 units account for 44% of all learning objectives:
- Organic chemistry (20%) is the largest single topic - alkanes, alkenes, alcohols, polymers
- Chemical reactions (13%) covers rates, equilibrium, and redox
- Atoms and bonding (11%) is foundational to everything else
Master these three units first. Start practicing with our IGCSE Chemistry topic quizzes.
Learning Objectives by Topic (Visual)
Bar length shows total objectives. Color split shows Core vs Supplement.
Key Formulas and Calculations
Unlike Physics, Chemistry has fewer mathematical formulas but more reactions and processes to remember. Extended students must master mole calculations - these appear in nearly every paper. The exam provides relative atomic masses, but you must know how to use them.
Formulas marked Supp are Supplement-only. Use our IGCSE Chemistry flashcards to review key concepts, or practice with topic quizzes.
Mole Calculations
- n = m / Mr Supp
- n = V / 24 (gas at r.t.p., dm³) Supp
- n = c × V (solutions) Supp
- c = n / V (concentration) Supp
Yield & Purity
- % yield = (actual/theoretical) × 100 Supp
- % purity = (pure/total) × 100 Supp
Energy & Analysis
- ΔH = Σ(bonds broken) - Σ(bonds made) Supp
- Rf = distance (substance) / distance (solvent) Supp
Key Ionic Equations
- H⁺ + OH⁻ → H₂O (neutralisation)
- CO₃²⁻ + 2H⁺ → H₂O + CO₂ (carbonates + acid)
Study Tip: Mole Calculations
The mole concept connects mass, volume, and concentration. Master the triangle method: put n (moles) at the top, then cover what you want to find. If you need n, multiply the other two. If you need one of the others, divide. Practice with past paper questions until it becomes automatic.
Recommended Study Approach
Master the Fundamentals First
States of matter, atomic structure, and bonding underpin everything else. Get these solid before moving on.
Learn Organic Chemistry Systematically
It's 20% of the syllabus. Learn the homologous series in order: alkanes → alkenes → alcohols → carboxylic acids → polymers.
Practice Mole Calculations (Extended)
If you're taking Extended, mole calculations appear in almost every paper. Practice until they're automatic.
Know Your Practical Techniques
Paper 6 tests practical skills. Know separation methods, titrations, and chemical tests thoroughly.
Use Past Papers Strategically
Practice with IGCSE Chemistry past papers to identify weak areas, then target those topics.
Key Takeaways
- 255 total objectives - 156 Core, 99 Supplement-only
- Organic chemistry is king - 20% of the syllabus, master it
- Know your tier - Core caps at grade C; Extended required for A*-B
- Mole calculations are crucial for Extended students
- Practical skills matter - Paper 6 tests real lab techniques
Frequently Asked Questions
Do exam questions follow this topic distribution?
There's no guarantee. While topics with more objectives (like organic chemistry at 20%) tend to appear more frequently, Cambridge can emphasize any topic in a given year. One paper might be heavy on stoichiometry, another on acids and bases. The syllabus distribution is a rough guide, not a prediction. The safest strategy: know everything, but spend proportionally more time on larger topics. Check past papers to see how questions actually vary.
Is IGCSE Chemistry harder than Physics?
They're different. Chemistry has more content to memorize (reactions, tests, organic chemistry) while Physics is more calculation-heavy. Chemistry Extended requires mastering mole calculations which many students find challenging initially.
Do I need to memorize all the reactions?
Yes, for the key reactions specified in the syllabus. These include reactions of acids with metals/bases/carbonates, displacement reactions, and organic reactions like fermentation and polymerisation. Understanding why reactions happen helps retention.
How important is organic chemistry?
Very important - it's the largest single topic at 20% of objectives. Questions on alkanes, alkenes, alcohols, carboxylic acids, and polymers appear in every exam. Learn the functional groups and typical reactions systematically.
Related Syllabus Guides
IGCSE Physics (0625)
326 learning objectives across 6 topics. More calculations than Chemistry - master the equations.
IGCSE Biology (0610)
389 learning objectives across 21 topics. The largest science syllabus - diagrams and explanations matter.
Official Resources
This guide is based on the Cambridge IGCSE Chemistry (0620) syllabus for examination from 2023-2025. Always refer to the official Cambridge syllabus for the most current information.