A-Level Chemistry 2026: What Each Exam Board Assesses

A-level Chemistry is a two-year linear qualification examined in the UK under five specifications — AQA 7405, Pearson Edexcel 9CH0, OCR Chemistry A H432, OCR Chemistry B (Salters) H433 and Eduqas — whose written papers run from 1 hour 45 minutes to 2 hours 30 minutes. Alongside the A*–E grade, every student in England also receives a Practical Endorsement recorded as Pass or Not Classified, which contributes nothing to that grade.

That last sentence surprises most families, and it is only the first of several places where the board a school happens to have chosen changes what a student should actually be doing. This page sets the five specifications side by side: what each paper covers, how long it lasts, what it is worth, what the exam hands you on a data sheet, and what June 2026 showed about where the grade thresholds now sit. If what you want instead is a person to work with your child each week, that is our chemistry tutor page.

Which exam board's A-level Chemistry is your child sitting, and how is it assessed?

Every school chooses its own board, and it is not always stated on a report. The quickest way to find out is the code printed on a past paper or an entry statement: 7405 is AQA, 9CH0 is Pearson Edexcel, H432 is OCR Chemistry A, H433 is OCR Chemistry B (Salters), and a paper headed “Component 1: Physical and Inorganic Chemistry” is Eduqas.

The content territory is broadly common across all five, because the Department for Education prescribes the subject content. What differs is how that content is cut into papers, how long a student sits in the hall, and how much each paper is worth. The spread is wider than families expect.

Three consequences follow from that table, and none of them are cosmetic. An Edexcel student sits a first paper of 1 hour 45 minutes for 90 marks and a third paper of 2 hours 30 minutes for 120 marks, so the single largest block of the qualification — 40% — is the synoptic paper that can draw on anything. An AQA student meets three evenly weighted papers of the same length. A Salters student sits a first paper worth 41% on its own, the heaviest single component of any of the five.

The practical rehearsal for that pattern matters more than a generic revision plan. Timed practice on Edexcel Paper 3 is a different exercise from timed practice on OCR Component 03, which is 70 marks in 1 hour 30 minutes and rewards speed on unfamiliar contexts. Full assessment detail sits in each board's own document, starting with the AQA specification at a glance.

What does the data booklet give you in the exam, and what has to be memorised?

This is the difference between the boards that no revision guide seems to mention, and it changes what a student needs to hold in their head on the morning of the exam.

AQA issues a four-page Data Booklet with its question papers. It carries the Periodic Table, Table A of infrared absorption data, Table B of ¹H NMR chemical shift data, Table C of ¹³C NMR chemical shift data, and a page of structural formulae — phosphate, glucose, 2-deoxyribose, the four DNA bases, six amino acids and Haem B. It carries no physical constants at all. Where a value such as the gas constant is needed, AQA prints it in the question itself.

OCR issues its own four-page Data Sheet for Chemistry A, and it opens with a block headed “General Information” that AQA students never see: the molar gas volume of 24.0 dm³ mol⁻¹ at room temperature and pressure, the Avogadro constant, the specific heat capacity of water, the ionic product of water at 298 K, the gas constant, and the Arrhenius equation written out in both its exponential and logarithmic forms.

A student who has been revising from a mixed set of past papers, or who has moved school mid-course, can arrive at the exam with the wrong expectation in either direction. The fix takes one lesson: print the data sheet your board actually issues, work with it beside you from the first week, and stop memorising what is going to be handed to you.

What is the Practical Endorsement, and can a student fail it?

In England the Practical Endorsement is a separate qualification outcome sitting alongside the A-level grade. It is assessed by teachers against the Common Practical Assessment Criteria, which are identical across the boards, and it is externally monitored through centre visits coordinated by JCQ.

Two facts about it are routinely misreported. The first is that it does not contribute to the grade: AQA states plainly that “A-level grades will be based only on marks from written exams”, and OCR's June 2026 boundary table prints the line “This component does not count towards overall mark” against component 04. Pearson is equally explicit that the endorsement “will not contribute to the overall grade for this qualification, but the result will be recorded on the student's certificate”.

The second is the outcome itself. There is no Fail. There are two published outcomes, Pass and Not Classified, and OCR's specification words it directly: candidates who fail to reach the minimum standard “will be recorded as ‘Not Classified’ and this will also be reported on the certificate”. A Not Classified line is visible to admissions tutors, and for chemistry, natural sciences, medicine and veterinary courses that is not a neutral mark on the page — even though it costs nothing in UCAS points.

Every board requires a minimum of twelve assessed practical activities. What differs is how those twelve are defined. AQA names twelve specific required practicals that every student completes. OCR — both Chemistry A and Salters — defines twelve Practical Activity Groups, PAG1 to PAG12, and a centre must cover all twelve groups but may choose or adapt the activity within each. Pearson identifies sixteen core practical experiments in the topics, against the same minimum of twelve assessed activities, which gives Edexcel centres four more prescribed experiments than the endorsement strictly requires.

How much of A-level Chemistry is actually mathematics?

Exactly 20% of the marks, and that figure is set by the Department for Education rather than by any board. The subject content document for A-level science states that assessment “will include at least 10% level 2 or above mathematical skills for biology and psychology, 20% for chemistry and 40% for physics”.

Chemistry therefore carries twice the mathematical load of A-level Biology and half that of A-level Physics. AQA and Pearson both restate the floor in their own specifications, Pearson adding that the minimum applies across the three papers taken together rather than paper by paper, and OCR words it as “at least 20% Level 2 (or above) mathematical skills for chemistry”.

Level 2 means GCSE Higher tier standard, so the mathematics itself is not beyond a student who has come through GCSE Maths comfortably. The difficulty is not the mathematics itself but the fluency demanded: moles, concentrations, titration arithmetic, enthalpy cycles, equilibrium constants, rate equations, logarithms in pH and the Arrhenius equation all appear under time pressure with method marks awarded step by step. A student who has dropped maths after GCSE has not made chemistry harder in content, but has removed the weekly practice that keeps this arithmetic automatic, and that is where the marks go.

What did each grade take in raw marks in June 2026?

The awarding bodies published their boundaries on results day, 13 August 2026. Because the papers carry different totals, the raw thresholds are only comparable within a board, but seeing them together makes the point that an A* is not a fixed percentage anywhere.

WJEC and Eduqas are not in that table on purpose. Their qualifications are unitised and their boundaries are published on a uniform mark scale unit by unit, so there is no single overall raw-mark total to set beside the four above. Quoting one would be inventing a comparison the board does not publish.

AQA also published notional component boundaries for the same series: an A* on Paper 1 sat at 91 of 105, on Paper 2 at 87 of 105, and on Paper 3 at 77 of 90. Those are illustrative rather than awarded grades, but they are the sharpest available answer to “what does an A* look like on one paper”, and the gap between Paper 1 and Paper 2 is a reminder that the boards do not set every paper to the same demand.

How many students sit A-level Chemistry, and how many get an A*?

JCQ published the summer 2026 tabulations on 13 August 2026, covering 906,425 A-level entries across the UK, of which 28.5% were awarded A*–A. Chemistry's own numbers sit some way above that headline.

Read that against the cohort a chemistry student is competing with. Almost a third of chemistry candidates reach A*–A, against roughly a quarter in biology, so a chemistry A is a less distinguishing grade than the subject's reputation for difficulty suggests. Entries rose from 63,538 in 2025 to 65,541 in 2026, while the A*–A rate slipped fractionally from 32.56% to 32.33% — a broader field, held to the same standard.

The distribution by sex is worth naming plainly rather than leaving in a footnote. Of the 2026 entry, 37,123 candidates were female and 28,418 male, so women are the clear majority of the cohort; yet 35.07% of male candidates reached A*–A against 30.23% of female candidates. Both figures are from JCQ's own tabulation, and the gap has been stable for several series. Anyone advising a student applying for 2026 entry to chemistry, medicine or pharmacy should know it, because it shapes what a school's own average looks like.

Why is A-level Chemistry assessed differently in Wales?

Because WJEC's Welsh A level is a different qualification from the Eduqas one it offers in England, and the difference lands exactly where families are least likely to check.

The WJEC (Wales) specification is unitised into five units: two AS units of 1 hour 30 minutes and 80 marks, worth 20% of the A level each; two A2 written units of 1 hour 45 minutes and 80 marks, worth 25% each; and A2 Unit 5, a practical unit of 60 marks worth 10% of the qualification. That unit is split into an Experimental Task of 30 marks and a Practical Methods and Analysis Task of 30 marks, and the main themes are shared with centres early in the spring term.

So in Wales, practical work carries marks. A tenth of the A level is earned at the bench and in a written analysis task, and a weak practical performance pulls the grade down directly. In England — on AQA, Edexcel, OCR A, OCR B and Eduqas alike — practical competence is certificated separately and carries no marks at all. A family moving between the two systems, or a Welsh student using English revision material, is working from the wrong model of where their grade comes from.

Which practicals does each board actually require?

AQA is the only one of the five that publishes a fixed, named list every student completes, introduced with the sentence “The following practicals must be carried out by all students taking this course”. The twelve are: making up a volumetric solution and carrying out a simple acid–base titration; measurement of an enthalpy change; investigation of how rate changes with temperature; test-tube reactions to identify cations and anions; distillation of a product from a reaction; tests for alcohol, aldehyde, alkene and carboxylic acid; measuring rate by initial rate and continuous monitoring; measuring the EMF of an electrochemical cell; investigating pH change when a weak acid meets a strong base and a strong acid meets a weak base; preparation of a pure organic solid and a pure organic liquid; test-tube reactions to identify transition metal ions in aqueous solution; and separation of species by thin-layer chromatography.

OCR takes the opposite approach on both its specifications: twelve Practical Activity Groups define the skills, and the centre selects, adapts or designs an activity within each group. Pearson identifies sixteen core practicals in the topic content, more than the twelve the endorsement requires, so an Edexcel student typically meets a wider set of techniques than the minimum.

None of this is optional revision. At least 15% of the marks in AQA's written papers assess knowledge and understanding of practical work, and Edexcel's Paper 3 is built around indirect practical assessment drawing on the core practicals. A student who watched the experiments rather than doing them loses those marks in the written exam, not in the endorsement.

How Leading Tuition supports A-level Chemistry by exam board

We start by establishing which specification the student is actually on, because a generic chemistry lesson wastes the part of the subject that is board-specific. From there the work is shaped by the paper the student is going to sit: Edexcel's 120-mark synoptic Paper 3 needs different rehearsal from OCR's 70-mark Unified Chemistry, and Salters' 110-mark first component needs different rehearsal again.

Our specialist tutors are selected for depth in chemistry rather than breadth across the sciences, and sessions concentrate on the places marks are lost at this level: mechanism arrows drawn from a charge rather than an electron pair, method marks skipped in multi-step calculations, and answers that are chemically right but phrased outside the mark scheme's wording. Rated 4.8/5 on Trustpilot, we also support the related routes — GCSE Chemistry for students still building the foundation, IB Chemistry for the diploma alternative, the A-Level Tuition hub for other subjects, and the Medicine Prep Hub where chemistry is the gateway grade.

Primary sources for this page: the Pearson Edexcel 9CH0 specification, the OCR Chemistry A H432 specification, the WJEC GCE Chemistry specification, the Department for Education's GCE AS and A level subject content for science, and JCQ's summer 2026 examination results.

Frequently asked questions about A-level Chemistry