GuidesChemistryPaper 1 · last-minute revision
3 days to go

GCSE Chemistry Paper 1: last-minute revision

Three days left and most of what costs you marks here isn't chemistry knowledge. It's the maths. Fix the calculation methods first, then lock in the four required practicals P1H always draws on.

AQA 8462 (topics apply broadly to Edexcel and OCR)
The plan

Your 3-day plan

One focus per day, building to a timed run. Work it in order.

3
3 days to go

Get the calculation methods automatic

  • Redo moles (n = mass ÷ Mr), percentage yield, and atom economy until you can set out the method without looking. These appear as a linked thread across both papers, not just in one topic.
  • Practise titration calculations end to end: moles from concentration and volume, then scaling up to find the unknown concentration.
  • Work through the reactivity series and displacement reactions. Write out the rule (more reactive metal displaces less reactive from a compound) and apply it to three different metal pairs.
2
2 days to go

Nail the four required practicals for this paper

  • Making salts (RPA1): write the method for making a soluble salt from an insoluble base (add excess base to acid, filter, evaporate, crystallise) and know why each step is done.
  • Energy changes (RPA4): practise plotting temperature-against-time graphs, drawing two lines of best fit, and extrapolating back to find the maximum temperature change.
  • Electrolysis of aqueous solutions (RPA3): learn the rules for what forms at each electrode (cathode: hydrogen unless the metal is less reactive than hydrogen; anode: oxygen unless a halide is present) and practise writing half equations.
  • Redraw the reaction profile diagrams for exothermic and endothermic reactions from memory, labelling activation energy and overall energy change correctly.
1
1 day to go

Light review: trust the method, don't cram new content

  • Skim your Knowledge Organisers for atomic structure, bonding, and the periodic table. These are the topics most likely to appear as short recall questions early in the paper.
  • Do one full past paper section under timed conditions to check your calculation method is fast enough, not just correct.
  • Check you can state symbols correctly in every equation you write out: (s), (l), (g), (aq). This is an easy mark examiners flag as commonly missed.
Priority order

The topics that come up most

Ranked from analysed past papers. Start at the top: if you run out of time, you will have covered the most-tested ground.

1

Moles & Calculations

Appeared in all 4 analysed sessions and threads across both papers. Percentage yield, atom economy and gas volume calculations all rely on the same method.

2

Titrations (HT)

Guaranteed content in every session analysed, always tied to RPA2. Concentration and mole calculations from titration data are a recurring multi-mark question.

3

Exothermic Reactions

Appeared in all 4 sessions, frequently as the largest question on the paper (14 marks in JUN24) and always linked to RPA4, the energy changes practical.

4

The Reactivity Series

Appeared in all 4 sessions with a rising trend. Displacement reactions and planning experiments around reactivity are common extended-response questions.

5

Electrolysis of Aqueous Solutions

Guaranteed content tied to RPA3. Electrode product rules and half equations are tested every session, sometimes with an unusual twist like coloured ion migration.

6

Metallic Bonding

Appeared in all 4 sessions. Explaining electrical conductivity and malleability using delocalised electrons is a frequent short-answer target.

7

Making Salts

Guaranteed content tied to RPA1 in every session. The insoluble salt method (excess base, filter, evaporate, crystallise) is tested as a sequence.

8

The Periodic Table

Appeared in all 4 sessions. Questions on group trends and why elements are placed where they are recur as reliable early-paper marks.

Your Knowledge Organisers

PrepWise has a one-page Knowledge Organiser for every topic above. Use them in your final 3 days with cover, recall, check, repeat: read it once, cover it, write out everything you remember, then check what you missed and go again.

Open the Chemistry Knowledge Organisers
Cheat sheet

Exam technique

Rules specific to Paper 1. On this paper, structure earns as many marks as knowledge.

1

Moles method card: n = mass ÷ Mr

Write the formula first, sub in the numbers, and always state your final answer with the correct unit (mol). If the question then asks for percentage yield, divide actual by theoretical and multiply by 100. Show the theoretical mass calculation as a separate step so you pick up method marks even if your final number is wrong.

2

Atom economy method card

Atom economy = (Mr of desired product ÷ sum of Mr of all reactants) × 100. Balance the equation first: an unbalanced equation gives you the wrong Mr totals and loses the whole calculation, not just one mark.

3

Titration method card

Use moles = concentration × volume (in dm³, so divide cm³ by 1000). Find moles of the known solution first, use the balanced equation to find the mole ratio, then calculate the concentration or volume asked for. Always check your ratio against the equation: 1:1 is common but not universal.

4

Balance every equation before you use it

If a question needs a balanced symbol equation as a step in a calculation, balance it before doing any maths. An unbalanced equation invalidates mole ratios and atom economy working, even if your arithmetic afterwards is perfect.

5

State symbols are free marks: don't skip them

Every equation you write for a mark should include (s), (l), (g), (aq) where relevant. Examiners specifically flag missing state symbols as a common way students lose marks they didn't need to.

6

6-mark level-of-response answers need structure, not length

For 'compare' or 'evaluate' questions, write a short plan first: one point for each side, then a linking sentence, then a conclusion that actually answers the question asked. Markers reward a complete, organised answer with a clear judgement over a long unstructured one.

Avoid these

5 mistakes that cost marks

The errors examiners see most on this paper. Each one is an easy mark you already know how to keep.

Forgetting to balance the equation before calculating atom economy or percentage yieldBalance the symbol equation first, every time. Write it out, count atoms, then start the calculation.

Mixing up cathode and anode products in electrolysis of aqueous solutionsLearn the rule as a pair: cathode gets hydrogen unless the metal is less reactive than hydrogen; anode gets oxygen unless a halide ion is present.

Leaving out state symbols in equationsAdd (s), (l), (g), (aq) to every species in every equation you write for marks. It costs nothing and is explicitly credited.

Using cm³ instead of dm³ in mole calculations from concentrationAlways convert cm³ to dm³ by dividing by 1000 before using moles = concentration × volume.

Describing metallic bonding as 'strong bonds between metal atoms' without mentioning delocalised electronsAlways name the delocalised electrons and the electrostatic attraction between them and the positive metal ions. That's where the marks are.

Exam day

The morning of the exam

The 60 minutes before you walk in. Review what you know and settle your nerves.

  • Read through your Knowledge Organisers for moles, titrations, and electrolysis one final time. Don't start anything new.
  • Check your calculator has fresh batteries and you know how to use standard form on it.
  • Remind yourself of the state symbols: (s) solid, (l) liquid, (g) gas, (aq) aqueous.
  • Have a highlighter ready to mark command words (calculate, explain, compare, evaluate) as you read each question.
  • Eat something before you go in. Low blood sugar makes multi-step calculations harder to hold in your head.
  • Arrive with time to spare so you're not rushing into the exam room stressed.

Now test yourself

The calculations only stick once you have actually done them under pressure. Practise exam-style Chemistry questions in PrepWise, get instant marking, and turn those method cards into marks.

Practise Chemistry questions

Start the 3-day plan now

Open the Chemistry Knowledge Organisers, quiz every priority topic and walk in ready. Free during alpha.

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