A revision plan becomes more useful when it starts with a piece of work: a mechanism with a missing charge, a calculation with the wrong sign, or an explanation that stops one step too soon. I have worked with students for five years, starting during my BEng. Here are six areas to review when planning A-Level Chemistry revision, with suggestions for practising each.
This article is primarily aimed at parents supporting a student in Year 12 or 13, though students themselves will find it directly useful. It assumes a working familiarity with A-Level Chemistry rather than starting from scratch.
Choose priorities from the student's work
Use the current specification as the checklist and recent work to decide where extra practice is needed. These six areas are a selection, not a ranking of exam frequency or a prediction of the next paper. They do not replace coverage of the full course.
For each topic, ask the student to explain an idea, attempt a question and review the answer. A missed mark may reveal a knowledge gap, an error in working or an incomplete explanation. The next task should address that particular difficulty.
Six areas to include in a Chemistry revision review
1. Organic reaction mechanisms
Organic reaction mechanisms connect knowledge of functional groups with the movement of electrons. Check which mechanisms the student's specification requires, then practise the relevant substitutions, additions, eliminations and other reactions.
Mechanism questions may allocate separate whole marks to features such as arrows, structures and charges. A partly correct answer can earn some of those marks; that is not the same as awarding half-marks. Use the mark scheme for the particular question.
How to revise it: Work through each mechanism type in isolation until you can reproduce it from memory. Then practise identifying which mechanism applies given only the reagent, the functional group, and the conditions. Past-paper questions in this area are the best resource; write out mechanisms by hand, then check against mark schemes word-for-word.
2. Equilibria and Le Chatelier's principle
Questions on equilibria appear at every level, from simple Le Chatelier predictions in AS to Kp and Kc calculations at A2, through to industrial applications (Haber process, Contact process) where students must explain why certain conditions are used rather than simply describe them.
A common misconception: students assume that adding a catalyst shifts the equilibrium position. It does not. It only speeds up the rate at which equilibrium is reached. This distinction appears in mark schemes repeatedly, and students who confuse it lose marks that are straightforward to secure.
How to revise it: Ensure you can write Kc and Kp expressions correctly and perform calculations under exam conditions. For industrial applications, practise explaining the commercial compromise, why the theoretically optimal conditions are not always used in practice.
3. Energetics and thermodynamics
Hess's law, Born–Haber cycles, entropy and Gibbs free energy bring together chemical ideas and calculations. Check the required content for the qualification, and practise sign conventions and clear working.
Try a Born–Haber cycle drawn in a different orientation. Can the student identify each energy change and construct the calculation, rather than reproduce a memorised diagram? That gives a useful next step for revision.
How to revise it: Do not memorise Born-Haber cycles as a fixed diagram. Instead, practise identifying the energy terms and checking that the cycle balances, regardless of how it is presented. For entropy calculations, be clear on when ΔG is negative and why this predicts spontaneity.
Explore our Chemistry tuition or enquire about support. A recent question or school assessment can provide a starting point for discussing the student's needs.
4. Electrochemistry and redox
Electrochemical cells, standard electrode potentials and redox equations are further areas to check against the specification. Practise both the calculation and the explanation of what the result tells you, including the limits of a feasibility prediction.
Students frequently lose marks by failing to write half-equations correctly, wrong number of electrons, incorrect balancing of oxygen by water, or hydrogen by H+. These are mechanical errors that practice eliminates reliably.
How to revise it: Develop a systematic method for constructing half-equations (balance atoms, then electrons). Practise calculating Ecell values from standard electrode potentials and interpreting what a positive Ecell value means for reaction feasibility.
5. Transition metals
Transition-metal chemistry connects electronic structure, oxidation states, complex ions, ligand substitution and catalysis. Use the student's specification to select the required reactions and explanations.
Ask the student to explain one observed colour change and write the corresponding equation. This can reveal whether the observation, structure and reaction have been connected.
How to revise it: Build a systematic overview of the first-row d-block elements (Ti to Cu), their common oxidation states, and the colours of their aqueous ions. Practise ligand substitution equations and ensure you understand why complex ions are coloured (d-d electron transitions and the role of the ligand field).
6. Practical knowledge and its assessment
All four specifications include a substantial practical component, whether through the separately reported practical endorsement (AQA, Edexcel and OCR) or a timetabled practical examination (Cambridge International). Written papers also include questions on experimental technique, error analysis, and the design of experiments.
Written practice can strengthen understanding of experimental design and data. It does not replace required laboratory work or the school's assessment of practical competence.
How to revise it: Review your core practical write-ups and identify the why behind each step (not just the procedure). Practise describing experiments in precise, concise language and be comfortable with error analysis: calculating percentage errors, identifying sources of systematic error, and suggesting improvements.
Understanding mark-scheme command words
One of the most transferable skills in A-Level Chemistry is learning to read the question correctly. Examiners use precise command words with specific expectations attached.
- State: a concise factual answer, no explanation required.
- Explain: a mechanistic or causal account, usually requiring reference to electrons, bonds, or energy.
- Describe: a factual account, often of a trend or observation, without necessarily explaining it.
- Suggest: you are expected to apply knowledge to an unfamiliar context; a correct response may differ from the mark-scheme example.
- Calculate: show all working. Method marks are available even if the final answer is wrong.
- Deduce: draw a logical conclusion from data or information given in the question.
An answer can contain correct chemistry and still miss what the question asks. Check the command word, the information supplied and the number of marks, then compare the response with the question's mark scheme.
Why 1:1 tuition works for Chemistry
A gap in one topic can affect work elsewhere. For example, understanding bonding and electron movement helps with organic mechanisms. In one-to-one work, the tutor and student can pause at that gap and work through it before returning to the original question.
At Sophyra Tutors, the starting point is the student's subject, specification and current needs. A selection of questions can help establish which ideas need explanation and which need further practice.
Further details on our A-Level Chemistry tuition are available on our A-Level Chemistry page.
A note on specification differences
The required depth, paper structure and practical assessment differ between qualifications. OCR A and OCR B are separate specifications; Pearson Edexcel A-Level and International A-Level also have different structures. Check the exact qualification code and examination year before choosing materials.
If your student is preparing for a specific exam board, it is worth checking the specification weighting document published by that board and ensuring their revision plan reflects it.
Share the subject, qualification and exam board when you enquire about Chemistry tuition. We can then discuss a suitable match and availability.
Frequently asked questions
Which A-Level Chemistry specification is the hardest?
There is no single specification that is hardest for every student. Compare the actual content, question formats and practical requirements, and use materials for the qualification the student is taking.
How many past papers should a student do before their exams?
Plan enough time to review each paper and act on the errors. Repeating papers without addressing the difficulties is less useful than returning to a question after the underlying idea has been practised.
Can a tutor help with the practical endorsement?
Yes, in the sense that a tutor can help a student understand the underlying chemistry behind each core practical and practise answering written questions about experimental technique. Tutors cannot sign off on the endorsement itself, which is assessed by the school.
Is A-Level Chemistry harder than A-Level Biology?
Both subjects require factual knowledge, application, analysis and practical understanding. The better question is which tasks the student finds difficult and what support would help with those tasks.
At what point in Year 12 should a student consider getting a Chemistry tutor?
Discuss support when a recurring difficulty becomes clear in classwork, homework or assessments. Schools set their own mock timetables, so there is no universal month when tutoring should begin.
Check the qualification materials
The AQA Chemistry 7405 specification sets out its subject content, assessment and practical requirements. For another board, use that board's current specification and the mark scheme for the exact paper. The revision suggestions above are guidance, not an analysis of topic frequency.