AQA and OCR are the two most popular exam boards for A-level Chemistry in England. AQA (7405) follows a linear structure across three written papers; OCR offers two distinct specifications — Chemistry A (H432) and the context-based Salters Chemistry B (H433). The right choice depends on how your child learns best.
What are the main AQA A-level Chemistry papers?
AQA A-level Chemistry (7405) consists of three written papers, all sat at the end of Year 13:
- Paper 1 (2 hours, 35%): Physical and inorganic chemistry — covers topics such as atomic structure, bonding, energetics, kinetics, equilibrium, and the periodic table
- Paper 2 (2 hours, 35%): Physical and organic chemistry — covers organic reactions, mechanisms, carbonyl chemistry, and synthesis
- Paper 3 (2 hours, 30%): A synoptic paper called "Chemistry in Context" that draws on the full specification and includes a data analysis section based on a pre-released article sent to schools before the exam
The Paper 3 pre-release article is distinctive: students receive it several weeks before the exam and use it to engage with a real-world chemistry application. This rewards students who read widely around chemistry and can think analytically, rather than just recall facts.
AQA also requires students to complete a Practical Endorsement: a non-exam assessment where teachers sign off twelve required practicals throughout the course. The endorsement is graded pass/fail and does not contribute to the A-level grade, but it must be passed for universities to recognise the qualification. Most chemistry degree courses also want to see the endorsement confirmed on the results slip.
What are the two OCR A-level Chemistry options?
OCR offers two distinct A-level Chemistry specifications with meaningfully different teaching approaches:
OCR Chemistry A (H432) takes a traditional, content-led approach similar in structure to AQA. It has three papers:
- Paper 1: Breadth in chemistry (2 hours 15 min, 37%)
- Paper 2: Depth in chemistry (2 hours 15 min, 37%)
- Paper 3: Unified chemistry (1 hour 30 min, 26%)
OCR Chemistry B — Salters (H433) is a context-based specification where chemistry is taught through real-world applications. Instead of starting with pure theory, Salters chemistry begins with scenarios — such as the chemistry of brewing, or the chemistry of the atmosphere — and uses these to introduce the underlying principles. It has three papers with a similar mark distribution to Chemistry A.
| Feature | AQA (7405) | OCR Chemistry A (H432) | OCR Salters B (H433) |
|---|---|---|---|
| Total written papers | 3 | 3 | 3 |
| Approach | Traditional, content-led | Traditional, content-led | Context-based, story-led |
| Pre-release paper element | Yes (Paper 3) | No | No |
| Practical endorsement | Yes (pass/fail) | Yes (pass/fail) | Yes (pass/fail) |
| Popularity | Highest in England | Second | Lower market share |
| Best for | Students who prefer clear topic-by-topic structure | Similar to AQA preferences | Students who engage better with real-world contexts |
Which specification is most widely taken?
AQA is by far the most popular A-level Chemistry specification in England. This means it has the largest bank of past papers, the most resources from third-party publishers, and the most familiar format to private tutors and AI tutoring tools. Students who study independently or who rely heavily on published revision materials generally find AQA best-resourced.
OCR Chemistry A is the second most popular traditional specification. OCR Salters B has a smaller but loyal following, particularly in schools where teachers strongly believe in context-based science education.
How do the required practicals differ?
All boards require students to complete a set of required practicals for the Practical Endorsement. The practicals themselves are governed by the same Ofqual requirements across all boards, so the skills assessed (titration, distillation, colorimetry, spectroscopy, etc.) are broadly the same. The difference lies in how each board organises and documents them. AQA requires twelve specified practicals; OCR has its own list of required activities.
The endorsement does not affect the A-level grade but is reported separately on the results certificate. Most chemistry degree programmes at Russell Group universities require the endorsement to be passed.
Frequently asked questions
Does the choice of A-level Chemistry board affect university admissions?
No. Universities specify A-level Chemistry as a requirement for chemistry, pharmacy, biochemistry, and medicine courses — not AQA Chemistry or OCR Chemistry. The board is invisible to admissions tutors. What matters is the grade achieved and the combination of A-levels.
Is OCR Salters Chemistry B harder than AQA?
The content is the same — all boards must cover the content mandated by Ofqual. Salters Chemistry B is often described as a different experience rather than harder or easier: some students thrive with its narrative, context-first approach, while others find the lack of clear topic boundaries confusing when revising. Ofqual's comparable outcomes policy means grade distributions are standardised across boards, so neither is systematically harder to achieve a given grade in.
How many past papers are available for each specification?
AQA has the most extensive back catalogue of past papers for A-level Chemistry, stretching across multiple specification cycles. OCR also has a reasonable supply. For the current specifications (first assessed in 2017 for most boards), students typically have around five to eight years of past papers to work from, plus specimen papers. All boards publish these freely on their websites.
Can a student self-study for A-level Chemistry without a school's lab access?
It is very difficult to complete the Practical Endorsement without access to a school or college laboratory. Private candidates entering through a test centre often need to make specific arrangements. The practical endorsement requires genuine lab experience — it cannot be completed on paper or through simulation alone. Students in this situation should contact their chosen exam board's private candidate guidance before committing to the route.
Explore how AI Tutors at aitutors.me support A-level Chemistry students with Socratic questioning through organic mechanisms, equilibrium calculations, and synoptic revision.