Pearson Edexcel International GCSE Chemistry (4CH1 / 4XCH1)
Edexcel IGCSE Chemistry
Syllabus 2026–2028
A comprehensive breakdown of the Pearson Edexcel International GCSE Chemistry (4CH1) specification. Linear vs modular routes, Paper 1C & 2C architecture, "Bold C" extension topics, core practicals, and Grade 9 strategy.
Specification Highlights
What Is Edexcel International GCSE Chemistry (4CH1)?
Edexcel International GCSE Chemistry (4CH1) is an untiered qualification graded on the 9–1 scale, assessed through two written examinations with no separate laboratory coursework exam. Unlike Cambridge IGCSE, all candidates sit the same examination papers, with high-level quantitative and organic topics concentrated in Paper 2C.
110 Marks · 2 Hours
Assesses core unbolded topics shared with Double Award Science (4SD0). Establishes the foundational Grade 4–7 threshold.
70 Marks · 1h 15m
Assesses the full syllabus with strong concentration on "Bold C" extension topics. Decides Grade 8 and 9 attainment.
Grades 9 to 1
Untiered single-tier entry. No separate practical paper; laboratory competencies are assessed directly within written items.
Linear Route (4CH1) vs Modular Route (4XCH1)
Pearson Edexcel provides two assessment pathways. Regardless of the scheduling format, the chemical concepts, practical skills, and grading criteria remain identical:
| Assessment Feature | Linear Specification (4CH1) | Modular Specification (4XCH1) |
|---|---|---|
| Exam Timing | All papers sat in a single examination series at the conclusion of the course | Units can be sat across multiple examination series (e.g., January / June) |
| Grading Framework | Standard 9–1 single-tier scale | Standard 9–1 single-tier scale |
| Curriculum Content | Official Pearson Issue 3 specification | Identical Issue 3 specification content |
| Series Availability | January and May/June series | January and May/June series |
Paper 1C vs Paper 2C Breakdown
Total Chemistry Assessment (100% / 180 Composite Marks) ├── Paper 1C (61.1% / 110 Marks / 120 mins) ── Core Content (Double Award Overlap) └── Paper 2C (38.9% / 70 Marks / 75 mins) ── Full Syllabus + "Bold C" Extension Content
| Paper Code | Time Allowed | Total Marks | Weighting | Specification Scope Assessed |
|---|---|---|---|---|
| Paper 1C | 2 Hours (120 mins) | 110 Marks | 61.1% | Core unbolded topics shared with Double Award Science (4SD0) |
| Paper 2C | 1 Hour 15 Mins (75 mins) | 70 Marks | 38.9% | All topics, with heavy emphasis on Triple Award "Bold C" extension units |
Official 4CH1 Specification Modules
The specification is organized into 4 major sections. Items flagged as Bold C are examined exclusively in Paper 2C:
Section 1: Principles of Chemistry
- States of Matter & Diffusion: Particle theory, state changes, cooling curves, diffusion in gases/liquids.
- Atomic Structure & Isotopes: Subatomic particles, isotopic abundance calculations, electron configuration.
- Formulae, Equations & Moles: Empirical/molecular formulae, reacting masses, molar gas volume ($24\text{ dm}^3$), % yield, atom economy.
- Bonding & Structure: Ionic, simple covalent, giant covalent (diamond, graphite, $C_{60}$), Metallic Bonding (Bold C).
- Electrolysis (Bold C): Molten vs aqueous electrolysis, half-equations, Faraday and $Q = I \times t$ calculations.
Section 2: Inorganic Chemistry
- Group 1 (Alkali Metals): Physical trends, reactivity with water and air, electron loss logic.
- Group 7 (Halogens): States and colours, displacement reactions, redox half-equations.
- Atmospheric Gases: Laboratory tests ($O_2, CO_2, H_2$), greenhouse warming, combustion of elements.
- Solubility Curves (Bold C): $\text{g}/100\text{g}$ water, crystallization calculations on cooling.
- Reactivity & Extraction: Rusting prevention, Blast Furnace & Aluminium Extraction (Bold C).
- Acids, Alkalis & Titrations: Soluble/insoluble salt preparation methods, indicators.
- Chemical Tests & Cations/Anions: Flame tests, precipitate tests ($Fe^{2+}, Fe^{3+}, Cu^{2+}, NH_4^+$), halide tests, pure water tests.
Section 3: Physical Chemistry
- Energetics & Calorimetry: Exothermic/endothermic profiles, $\Delta H$ notation, $Q = mc\Delta T$ calorimetry.
- Bond Energy Calculations (Bold C): $\Delta H = \text{Bonds Broken} - \text{Bonds Formed}$.
- Rates of Reaction: Collision theory, surface area, temperature, catalysts, disappearing cross/gas collection.
- Reversible Reactions & Equilibria (Bold C): Dynamic equilibrium, Le Chatelier shifts with temperature/pressure.
Section 4: Organic Chemistry
- Introduction & Homologous Series: Functional groups, isomerism, IUPAC naming.
- Crude Oil Refining: Fractional distillation, cracking, fuel combustion, environmental impact.
- Alkanes & Alkenes: Substitution vs addition, bromine water unsaturation test.
- Alcohols (Bold C): Fermentation vs hydration of ethene, microbial/chemical oxidation to carboxylic acids.
- Carboxylic Acids & Esters (Bold C): Esterification, naming and uses of esters.
- Polymers: Addition polymerisation, Condensation Polymers & Polyesters (Bold C).
The "Bold C" Factor Explained
In the Pearson specification, learning objectives marked in bold with a "C" code are tested exclusively in Paper 2C. These topics represent the primary hurdle between Grade 7 and Grade 9:
Grade 7 Benchmark ──► Solid performance across Paper 1C core concepts
Grade 8–9 Mastery ──► Flawless execution on Paper 2C "Bold C" topics:
• Solubility curve crystallization calculations
• Aqueous electrolysis half-equations and Faraday calculations
• Bond energy arithmetic (endothermic vs exothermic)
• Le Chatelier equilibrium shifts under temperature/pressure
• Alcohols, esters, and condensation polymer structuresExaminer Insight: Students targeting top scores cannot treat Paper 2C as a simple revision of Paper 1C. Although Paper 2C carries under 40% of total marks, its higher question complexity determines final Grade 8 and 9 allocations.
Core Practical Competencies (15%+ Marks)
Without a separate coursework paper, standard laboratory procedures are evaluated directly in written questions:
Essential Core Practicals
• Solubility: Measuring how $KNO_3$ solubility varies with temperature.
• Calorimetry: Combustion of alcohols and neutralisation temperature changes.
• Rates of Reaction: Gas syringe volume collection and disappearing cross turbidity.
Preparative & Analytical Practicals
• Salt Preparation: Preparing pure, dry $CuSO_4$ crystals from $CuO$ and dilute $H_2SO_4$.
• Acid-Base Titration: Conical flask, burette reading precision, methyl orange indicator.
• Organic Synthesis: Preparing ethyl ethanoate using a heating water bath.
Pearson Edexcel (4CH1) vs Cambridge CAIE (0620)
| Specification Feature | Pearson Edexcel IGCSE (4CH1) | Cambridge IGCSE (0620 / 0971) |
|---|---|---|
| Tiering Model | Untiered (Grades 9–1 for all candidates) | Core (Grades 5–1) and Extended (Grades 9–1) |
| Exam Paper Count | 2 Written Papers (Paper 1C & 2C) | 3 Papers (MCQ + Theory + Practical/ATP) |
| Practical Assessment | Embedded inside Papers 1C and 2C | Dedicated Paper 5 (Lab) or Paper 6 (ATP) |
| Organic Focus | Esters, condensation polymers, alcohols in depth | Broad industrial fuel & macromolecule overview |
Grade 9 Four-Phase Revision Roadmap
Phase 1: Foundation (Syllabus Mapping) └── Complete review of 4CH1 core units; master ionic nomenclature and mole calculations. Phase 2: Targeted Paper 1C Drilling └── Work through recent Paper 1C series; ensure speed and accuracy on 1–3 mark questions. Phase 3: Deep Dive into "Bold C" & Paper 2C └── Master electrolysis, bond energies, Le Chatelier equilibria, and polyesters. Phase 4: Practical & Experimental Rigor └── Review apparatus setups, control variables, sources of error, and titration calculations.
Related IGCSE & Chemistry Resources
IGCSE Chemistry Hub → Cambridge IGCSE Chemistry Tutoring → Edexcel Past Papers → Cambridge Past Papers → Edexcel vs Cambridge Comparison → IGCSE Kimya Özel Ders (TR) →Frequently Asked Questions
Is Edexcel IGCSE Chemistry harder than Cambridge CIE 0620?
Neither is inherently harder; they evaluate skills differently. Cambridge uses three separate papers including multiple-choice and dedicated practical papers. Edexcel assesses candidates across two long-form written papers, demanding greater stamina, extended written explanations, and deeper organic synthesis.
Can I sit Edexcel IGCSE Chemistry as a private candidate?
Yes. Because Pearson Edexcel assesses experimental skills entirely within written examination papers (with no compulsory laboratory coursework), it is highly accessible for private and home-schooled candidates worldwide.
What is the difference between Single Award (4CH1) and Double Award (4SD0)?
Double Award Science students sit Paper 1C alongside Biology Paper 1B and Physics Paper 1P for a combined two-grade qualification. Single Award (Triple) Chemistry students take both Paper 1C and Paper 2C to earn a standalone Chemistry qualification.
What does "Bold C" mean in the Edexcel specification?
Bold C refers to extension learning objectives printed in bold typeface with a "C" code in the specification. These topics appear exclusively on Paper 2C and carry the decisive marks required for Grades 8 and 9.
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