GCSE Chemistry past papers, marked against the real criteria

AQA, Edexcel and OCR Chemistry papers with the mark scheme sitting beside every question. You write the answer in full, working included; it is marked the way an examiner marks it, mark by mark, including the step in a calculation that scores on its own and the word in an explanation that the rest of the answer hangs on.

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What "marked against the criteria" actually means

A Chemistry explanation is marked in pieces. A three-mark question is three separate ideas, and an answer can hold two of them, read perfectly well, and still come back one short. Here is a structure-and-bonding question in the style of an AQA Paper 1.

The same swap costs marks all over the paper. Metals conduct because they have delocalised electrons that are free to move, not because "the electrons move". An ionic compound conducts when molten or dissolved because the ions are then free to move, and that clause is the mark. Ions are held by electrostatic forces of attraction between oppositely charged ions, not by "opposite charges attracting". Each qualifier is a mark that somebody did not get.

Combined Science and Triple, and the papers themselves

Most pupils meet Chemistry as one third of Combined Science and leave with two grades covering all three sciences; a smaller number sit Triple and get a separate Chemistry grade. Either way it is examined in two papers, and the content is split between them rather than repeated: broadly, atomic structure, bonding, quantitative chemistry, chemical changes and energy changes on the first paper, then rates and equilibrium, organic chemistry, chemical analysis, the atmosphere and using resources on the second. AQA numbers them Paper 1 and Paper 2; Edexcel sets 1CH0/1F–1H and 1CH0/2F–2H; and OCR numbers by tier across its two suites — Gateway (J248) sets Papers 1 and 2 at Foundation and Papers 3 and 4 at Higher, while Twenty First Century (J258) calls them Breadth and Depth instead of numbering them. Foundation tier caps the grade however good the answers are — at 5 on a separate paper, and at 5–5 on Combined Science, which is graded on a seventeen-point paired scale from 1–1 to 9–9.

A periodic table is supplied with every Chemistry paper — as a separate insert on AQA and OCR, and on Edexcel too since summer 2024, when it moved off the back cover. It gives the relative atomic masses and no mark is ever for remembering one. What is not given is the formula of a compound, the colour of a precipitate or the result of a flame test, and those carry marks on every paper.

Calculations, equations, and where their marks sit

Chemistry calculations are marked in steps, and the steps score even when the final number is wrong. A percentage yield or concentration question is typically one mark for the rearrangement, one for the substitution and one for the answer, so a pupil who sets it up correctly and then mis-keys the division keeps most of the marks — but only if the setting-up is on the page. Schemes also carry errors forward: a wrong value used correctly in the next step still earns that step. For a short calculation a correct final answer on its own can take full marks, which is the one case where working is optional; a wrong one on its own takes none.

Two things the question itself decides. If it asks for an answer to a given number of significant figures, that instruction is worth a mark, and rounding partway through a multi-step calculation is the quiet way to lose it. If the answer space has no units printed, the units belong in your answer.

Balanced equations are marked as formulae first, balancing second. The formula of each substance has to be right before any balancing mark is available, which is why altering a subscript to make the oxygens work — writing H₂O₂ instead of putting a 2 in front of H₂O — loses everything: it balances an equation about a different compound. Balancing numbers go in front, never inside. State symbols are only required when the question asks for them, and then they are their own mark, with (aq) and (l) the pair that gets confused.

The required practicals, and the questions they ask

The named practicals — making a soluble salt, titration, electrolysis, measuring a temperature change, rates of reaction, chromatography, analysing and purifying water — are examined in the written papers rather than assessed in the lab. The questions almost never ask what the result was. They ask why a particular step is in the method, because the result is in the textbook and the reason is what shows you stood there and did it.

How do you know the solid is in excess. Why is the mixture filtered. Why is the filtrate warmed on a water bath rather than over a Bunsen flame. Why must the bung go into the flask the moment the acid meets the metal. Why heat the dish until the mass stops changing. Each of those is one mark with one accepted reason behind it, and a plausible-sounding near miss scores nothing. Where a question tells you to leave anomalous results out of a mean, identifying the anomaly is itself one of the marks, and using all the readings loses the marks that follow it.

The longer six-mark questions, usually a method to plan or a process to describe, are marked by level rather than by ticking points: a band for how complete and coherent the whole answer is, with indicative content as a guide. Six true sentences in no particular order sit in the bottom band. Four steps in the order you would actually do them, with the variable you control named, sit in the top one.

The papers

28 questions across 6 papers, each with its own criteria. Everything here is written in the boards' own format and judged against their published criteria; the papers themselves belong to the boards and are not reproduced here.

Try it on your own answer

Open a paper, write what you would have written in the exam, including the wrong bits, and read what comes back. It is free to start and does not ask for a card.

Open GCSE Chemistry

The other subjects

Twenty-three in one place, aligned to AQA, Edexcel and OCR.