Cambridge O Level Chemistry Tutors Online

Cambridge O Level Chemistry is syllabus 5070. This page works from the syllabus for exams in 2026, 2027 and 2028. Exams are available in the June and November series, and the syllabus notes that it is not available in all administrative zones.

All candidates take three components, and all candidates are eligible for grades A* to E. There is no Core and Extended tier.

Paper 1 is Multiple Choice. It lasts 1 hour, carries 40 marks and is worth 30%. It contains 40 four-option multiple-choice questions, all compulsory, and tests assessment objectives AO1 and AO2.

Paper 2 is Theory. It lasts 1 hour 45 minutes, carries 80 marks and is worth 50%. It contains compulsory short-answer and structured questions, and it also tests AO1 and AO2 only.

The third component is the practical assessment. Candidates take either Paper 3, the Practical Test, lasting 1 hour 30 minutes, or Paper 4, the Alternative to Practical, lasting 1 hour. Both carry 40 marks, both are worth 20%, and both are externally assessed.

The difference is physical rather than academic. Candidates taking the Practical Test must do experiments in a laboratory as part of the test. Candidates taking the Alternative to Practical must not. Everything else is the same: both require the same experimental skills to be developed and learned, both require an understanding of the same experimental contexts, and both test the same assessment objective, AO3.

One practical detail is worth knowing before the exam, because it changes how a candidate prepares. Notes for use in qualitative analysis are provided for both Paper 3 and Paper 4. So the ion and gas identification work is supported by a printed reference in the exam itself, and the skill being tested is how confidently a candidate uses that reference, not whether they have memorised it.

The content is organised into twelve topics. They are states of matter; atoms, elements and compounds; stoichiometry; electrochemistry; chemical energetics; chemical reactions; acids, bases and salts; the Periodic Table; metals; chemistry of the environment; organic chemistry; and experimental techniques and chemical analysis.

Notice that the last of those twelve is experimental techniques and chemical analysis. Practical chemistry is not only assessed in the practical paper: it is also a taught topic that Paper 2 can examine.

The assessment objectives are three. AO1 is knowledge with understanding, covering scientific phenomena, facts, laws, definitions, concepts and theories; scientific vocabulary, terminology and conventions including symbols, quantities and units; scientific instruments and apparatus including techniques of operation and aspects of safety; and scientific and technological applications with their social, economic and environmental implications. AO2 is handling information and problem solving. AO3 is experimental skills and investigations.

Overall, AO1 is worth 50 per cent, AO2 is worth 30 per cent and AO3 is worth 20 per cent of the qualification. Per component, Paper 1 is 63 per cent AO1 and 37 per cent AO2. Paper 2 is 63 per cent AO1 and 37 per cent AO2, exactly the same split. Papers 3 and 4 are 100 per cent AO3.

So the practical paper is the only place where experimental skill is tested, and it is tested purely. A candidate who knows the chemistry but has never run a titration or described a gas test will lose that 20 per cent in full, no matter how good the written papers are.

The syllabus publishes the experimental contexts the practical paper can draw on. These are chemistry specific and worth reading carefully, because they are the shortest revision list in the document. Candidates may be asked about simple quantitative experiments including measurement of volumes of gases or solutions and liquids, masses, temperatures, times and lengths; rates of reaction; salt preparation; separation and purification techniques including filtration, crystallisation, simple distillation, fractional distillation and chromatography; electrolysis; identification of metal ions, non-metal ions and gases; chemical tests for water; test-tube reactions of dilute acids including ethanoic acid; tests for oxidising and reducing agents; heating and cooling curves; titrations; solubility; melting points and boiling points; displacement reactions of metals and halogens; temperature changes during reactions; the conditions under which iron rusts or other metals corrode; and procedures using simple apparatus in situations where the method may not be familiar to the candidate.

Beyond the experiments themselves, the syllabus lists three skill families. The first is selecting and safely using techniques, apparatus and materials, which includes identifying apparatus from diagrams or descriptions, drawing, completing or labelling diagrams of apparatus, using or explaining the use of common techniques, selecting the most appropriate apparatus or method and justifying the choice, describing qualitative and gas tests, explaining hazards and identifying safety precautions, and explaining techniques used to ensure the accuracy of observations and data.

The second skill family is planning experiments and investigations. Candidates may be asked to identify the independent and dependent variable, describe how and explain why variables should be controlled, suggest an appropriate number and range of values for the independent variable, suggest the most appropriate apparatus or technique and justify it, describe experimental procedures, identify risks and suggest safety precautions, describe how to record results, describe how to process results to form a conclusion or evaluate a prediction, and make reasoned predictions of expected results.

The third is making and recording observations, measurements and estimates, then interpreting and evaluating them. That includes taking readings from analogue and digital apparatus or from diagrams of apparatus, reading to the nearest half-scale division where required, taking sufficient measurements including repeats where appropriate, recording observations and measurements systematically in a suitable table with appropriate units, processing data for further calculation or graphing, presenting data graphically including best-fit lines, analysing and interpreting data presented graphically, using interpolation and extrapolation to determine a gradient or intercept, and forming conclusions justified by reference to observations and data.

The syllabus also sets out conventions that affect marks in every paper. It follows generally accepted international practice and specifically the Association for Science Education document Signs, Symbols and Systematics: The ASE Companion to 16 to 19 Science. The traditional names sulfate, sulfite, nitrate, nitrite, sulfuric acid and nitric acid are used in question papers, and candidates are credited for traditional or systematic names in their answers except where specifically asked to use oxidation numbers to deduce or understand systematic names. Decimal markers are printed as a single dot on the line, and candidates are expected to follow that convention. Numbers from 1000 to 9999 are printed without commas or spaces, and numbers of 10 000 or more are printed without commas with a space between each group of three digits. The cubic decimetre is used in place of the litre or the symbol l, and imperial or customary units such as the inch and degree Fahrenheit are not acceptable.

That last set of conventions is easy marks to give away. A candidate who writes a litre sign or a comma in a four figure number, or who works in Fahrenheit, is working against the paper's own notation.

The qualification is graded A*, A, B, C, D or E.