Edexcel IGCSE Chemistry (4CH1): Paper 1 vs Paper 2, With a Revision Plan
Edexcel IGCSE Chemistry (4CH1) splits across two written papers with different coverage, and students who revise as though the papers are interchangeable tend to arrive at Paper 2 under-prepared. This guide sets out what each paper covers and builds a revision plan around the four things both papers test.
What is the difference between 4CH1 Paper 1 and Paper 2?
Paper 1 covers the bulk of the specification and carries the larger mark total. Paper 2 concentrates a defined subset of topics, including content assessed at the higher level of demand. Both papers test calculations, equations, explanation and practical analysis, so the skills overlap even where the content does not.
Check your specification. Topic allocation between papers is set by the specification version your centre is entered for, and it has changed between versions. Get the correct one from Pearson and mark which topics sit on which paper before planning.
What we see on our own learning portal: Visitors to Tutopiya’s Edexcel IGCSE Chemistry pages fell 17% month on month in the 30 days to 5 November 2026 — a milder dip than the Cambridge subjects examined in the October/November series. (Tutopiya learning portal data, 30 days to 5 November 2026.)
The four things both papers test
Revising by topic alone misses this. Every question on either paper is one of four types.
| Demand | What it looks like | Where marks are lost |
|---|---|---|
| Calculation | Moles, masses, yields, concentrations, gas volumes | Ratio from the equation; units; significant figures |
| Equations | Balanced symbol equations, ionic equations, half equations | Balancing; state symbols; spectator ions |
| Explanation | Why a trend occurs, why a method works | Describing instead of explaining |
| Practical analysis | Method, apparatus, observations, errors, data | Vague improvements; unnamed apparatus |
Calculations: the five-step method
The most common error in IGCSE chemistry calculations is applying the moles of one substance to another without using the ratio from the balanced equation.
Write these five lines every time:
- The balanced equation
- Moles of the known substance — mass ÷ Mr, or concentration × volume
- The ratio from the equation, written explicitly
- Conversion to the required quantity
- Units and significant figures
Step three is the one students skip, and writing it as a separate line makes that nearly impossible.
The calculation types to drill:
- Relative formula mass
- Moles from mass; mass from moles
- Reacting masses from a balanced equation
- Percentage yield and percentage composition
- Empirical and molecular formulae
- Concentration in g/dm³ and mol/dm³, and conversions between them
- Gas volumes at room temperature and pressure
- Titration calculations
Forty questions across these types, marked, is the single highest-return block of revision for this qualification.
Equations
- Count atoms on both sides for every element.
- For ionic equations, check the charge balances too, and include only the species that change.
- State symbols when asked, and correctly — aqueous and liquid are not interchangeable.
- For half equations, electrons on the correct side: gained at the cathode, lost at the anode.
Explanations: answer the command word
| Command word | What the mark scheme wants |
|---|---|
| State / give | A short fact, no reasoning |
| Describe | What happens, in sequence |
| Explain | Why it happens, with a reason |
| Suggest | Applying principles to an unfamiliar context |
| Compare | Both items, with explicit linking language |
Example. Explain why the melting point increases down Group 7.
Describes: “The melting points get higher down the group.”
Explains: “Down Group 7 the molecules have more electrons, so the intermolecular forces between molecules are stronger, and more energy is required to overcome them, so the melting point increases.”
Three creditable ideas rather than a restatement of the trend.
Practical questions without a practical exam
Because 4CH1 has no separate practical examination, students sometimes conclude practical work is not examined. It is — within the written papers.
What you need:
- Named apparatus: burette, pipette, conical flask, measuring cylinder, not “tube” or “container”
- Variables: independent, dependent and controlled, for any experiment described
- Observations: precise colour changes, effervescence, precipitate formation
- Errors: specific, with the direction of their effect
- Improvements: specific and plausible — “repeat and take a mean” is worth little on its own
Core experiments to know: titration technique, preparation of soluble and insoluble salts, electrolysis of molten and aqueous compounds, rates of reaction investigations, tests for cations, anions and gases, and chromatography including Rf calculation.
The ion tests must be automatic. Reagent, observation, conclusion for each. These are free marks every series.
A revision plan
| Weeks | Focus |
|---|---|
| 1 | Map the specification: which topics are on which paper |
| 2–3 | Calculations: forty questions, five-step method enforced |
| 4 | Equations: thirty balancing, ionic and half equation questions |
| 5 | Ion tests, gas tests and practical techniques, tested from memory |
| 6 | Explanation questions by command word: twenty past questions |
| 7 | Organic chemistry and the higher-demand Paper 2 content |
| 8–9 | Full past papers for both papers, under time |
| 10 | Error log and examiner reports from three series |
Sources and a caveat
Specification content, paper structure and assessment objectives are from the Pearson Edexcel International GCSE in Chemistry (4CH1), available at Pearson qualifications. Topic allocation between Paper 1 and Paper 2 is defined by the specification and has differed between versions — confirm the version your centre uses before planning. Mark schemes and examiner reports for recent series are the definitive guide to how marks are awarded.
Primary sources
- Pearson Edexcel International GCSE Chemistry (4CH1)
- Pearson Edexcel International GCSEs
- Pearson Edexcel — qualifications
Portal figures are Tutopiya learning portal data read from the Learning Portal growth and health dashboard on 6 November 2026, comparing the 30 days to 5 November 2026 with the preceding 30 days.
Next step: work twenty past calculation questions using the explicit five-step method, writing the ratio line every time. If that recovers marks, apply the same discipline to equations. For structured marking and practical-question practice, work with an IGCSE Chemistry tutor.
Frequently asked questions
What is the difference between Paper 1 and Paper 2 in Edexcel IGCSE Chemistry? +
Paper 1 covers the majority of the specification and carries the larger share of the marks. Paper 2 covers a defined subset of topics in greater depth, including the content assessed only at the higher level of demand. Both include calculations and practical-based questions.
Is there a practical exam in Edexcel IGCSE Chemistry 4CH1? +
There is no separate practical examination. Practical skills are assessed within the written papers through questions on method, apparatus, variables, observations and data analysis, so experimental knowledge is examined even though there is no practical test.
What calculations are on 4CH1? +
Relative formula mass, moles from mass and from concentration, reacting masses, percentage yield, empirical and molecular formulae, concentration conversions, gas volumes at room temperature and pressure, and titration calculations.
How do I revise for Edexcel IGCSE Chemistry? +
By question type. Calculations, equations, explanations and practical analysis are the four recurring demands. Drill each separately against official mark schemes before attempting whole papers.
Which paper is harder? +
Paper 2 is generally regarded as more demanding because it concentrates the higher-demand content, but Paper 1 carries more marks. Neither should be prioritised at the expense of the other.
Has demand for Edexcel IGCSE Chemistry resources changed? +
Visitors to Tutopiya's Edexcel IGCSE Chemistry pages fell 17% month on month in the 30 days to 5 November 2026, a milder dip than the Cambridge subjects examined in the October/November series. Figures come from Tutopiya's own learning portal analytics, read from the Learning Portal growth and health dashboard on 6 November 2026.
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Mahira Kitchil
Project Head of AI Buddy
Mahira Kitchil is Project Head of AI Buddy at Tutopiya, where she works with schools and families across the UK, Malaysia, India and the Gulf. She follows Cambridge, Pearson Edexcel, AQA, OCR and IB announcements as they land in each market, and writes these guides from published syllabuses, board timetables and regulator guidance rather than second-hand summaries.
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