Cambridge O Level Chemistry (5070) Past Papers: Grade Thresholds and Examiner Report Notes

This page is a guide to past papers for Cambridge O Level Chemistry (5070). It covers seven series, June 2023 to June 2026. The grade thresholds are copied from Cambridge’s grade-threshold documents, and the examiner notes are our own summaries of Cambridge’s Principal Examiner Reports for Teachers. We do not host any papers: every paper, mark scheme and report comes from Cambridge.

Where to get the official papers

• Cambridge O Level Chemistry (5070) syllabus page
• 5070 past papers page

Cambridge publishes recent papers, mark schemes, examiner reports and grade thresholds on the syllabus’s past-papers page; older series are available to schools through the School Support Hub.

Use the three documents together. Sit the paper first, under timed conditions. Mark it with the mark scheme, so you see exactly which points earn credit. Then read the examiner report (or our notes below) for that series. It tells you why answers that looked right still lost marks.

Which syllabus were these papers set on? The June 2023 to November 2025 papers were set on the 2023-2025 syllabus. Cambridge has replaced it with the 2026-2028 syllabus, and the June 2026 papers were set on that one. Cambridge reports no significant changes affecting teaching between the two versions, but check the syllabus version on each paper’s front cover against the current syllabus before you rely on an old question. The topic names below are the current syllabus’s.

Series index

Series	Papers (components) examined	Examiner report notes	Grade thresholds
June 2026	11, 12, 21, 22, 32, 41, 42	Yes	Yes
November 2025	11, 12, 21, 22, 31, 32, 41, 42	Yes	Yes
June 2025	11, 12, 21, 22, 31, 32, 41, 42	Yes	Yes
November 2024	11, 12, 21, 22, 31, 32, 41, 42	Yes	Yes
June 2024	11, 12, 21, 22, 31, 32, 41, 42	Yes	Yes
November 2023	11, 12, 21, 22, 31, 32, 41, 42	Yes	Yes
June 2023	11, 12, 21, 22, 31, 32, 41, 42	Yes	Yes

Earlier series are on Cambridge’s past-papers page and are not summarised here.

Papers 11 and 12 are Multiple Choice. Papers 21 and 22 are Theory. Papers 31 and 32 are Practical Tests, and Papers 41 and 42 are Alternative to Practical. In June 2023, June 2024 and June 2025 the report says too few candidates sat Paper 31 for a meaningful report, and the June 2026 report has no Paper 31 section.

What examiners keep saying

These are the mistakes that come back series after series, grouped by the syllabus’s own topic names.

• Stoichiometry: the mole. Ignoring or inverting the mole ratio, and comparing masses instead of moles to find the excess reagent. June 2023, November 2023, June 2024, November 2024, November 2025, June 2026.
• Stoichiometry: gas volumes and rounding. Not converting cm³ to dm³, dividing by the molar volume instead of multiplying, misusing the Avogadro constant, rounding early and giving the wrong significant figures. June 2024, November 2024, June 2025, November 2025, June 2026.
• Stoichiometry: formulae and relative masses. Wrong formulae for salts with polyatomic ions, so equations cannot balance. Using Ar for Mr, taking relative atomic mass as a simple mean, or mishandling water of crystallisation in a molar mass. June 2024, June 2025, November 2025, June 2026.
• Electrochemistry. Electrons on the wrong side of half-equations, anode equations reversed, halogens written as single atoms, ions named as products, and conduction put down to electrons instead of mobile ions. All seven series.
• Chemical energetics. Energy profile arrows pointing the wrong way, double-headed or missing the right levels; bond making said to use energy; the final subtraction in bond-energy sums reversed. June 2023, November 2023, June 2024, November 2024, June 2025.
• Chemical reactions: rate of reaction. Saying “more collisions” instead of more frequent or more successful collisions, mentioning kinetic energy without particles, and treating rate as time taken. June 2023, November 2023, June 2024, November 2024, June 2025, June 2026.
• Chemical reactions: reversible reactions and equilibrium. Using rate ideas for equilibrium, saying the reaction “moves” or is “favoured” rather than the position of equilibrium, and leaving out moles of gas in pressure answers. June 2023, November 2023, June 2024, November 2024, June 2025, November 2025.
• Chemical reactions: redox. Calling a whole compound oxidised or reduced, writing oxidation numbers as charges or without a sign, and confusing halogen with halide. November 2023, June 2024, June 2025, June 2026.
• Atoms, elements and compounds. Giving intermolecular forces to diamond, graphite or ionic solids; not saying delocalised electrons are mobile; describing ionic bonds without the attraction between oppositely charged ions. November 2023, June 2024, June 2025, November 2025, June 2026.
• Metals. Alloy hardness not explained by different-sized atoms stopping layers sliding; barrier and sacrificial protection confused; blast furnace chemistry left blank. November 2024, June 2025, November 2025, June 2026.
• Acids, bases and salts: preparation of salts. Heating to dryness instead of to saturation, and leaving out excess solid, filtration, washing or drying. June 2023, November 2023, November 2024, June 2026.
• Organic chemistry. Carbon with the wrong number of bonds, O–H bonds left out, molecular, structural and displayed formulae mixed up, and ester names reversed. June 2023, June 2024, November 2024, June 2025, June 2026.
• Organic chemistry: polymers. Ester or amide linkages with extra atoms, missing continuation bonds, and side chains drawn in the backbone. November 2023, November 2024, June 2025, November 2025.
• Experimental techniques and chemical analysis: ion and gas tests. Flame tests without a blue, non-luminous flame; sodium read as calcium; chlorine written for chloride; ammonium and nitrate tests mixed up; a gas named instead of something seen. June 2023, June 2024, November 2024, June 2025, November 2025, June 2026.
• Experimental techniques and chemical analysis: titrations and graphs. Burette readings not to one decimal place, “best” titres chosen by size, all titres averaged, universal indicator chosen, and dot-to-dot lines instead of best fit. June 2023, June 2024, November 2024, June 2025, November 2025, June 2026.

Exam technique the reports repeat:

• Read the whole stem, then go back to it. Look for bold words, excess reagent and required significant figures. Give a name or a formula exactly as asked. All seven series.
• Show every step of working. Label each value so error-carried-forward credit can be given, and round only at the end. All seven series.
• An observation is what you see. Not a product name, not a conclusion. Write “colourless solution” with its noun, and say “precipitate”. November 2023, November 2024, June 2025, November 2025, June 2026.
• Use the qualitative analysis notes. Copy their wording, but know when a question needs your own knowledge. All seven series.
• Plans: cover every bullet. Name the apparatus, say why each piece is needed, control variables and use only the chemicals allowed. June 2023 to November 2025.
• Do real practical work. Flame tests with a proper Bunsen burner, titrations and precipitates teach you what you will be asked to describe. June 2023, June 2024, November 2024, June 2025, November 2025.

June 2026

This series was set on the current 2026-2028 syllabus. Quantitative chemistry carried a lot of weight: reacting masses, gas volumes, excess reagents and water of crystallisation. Rate had to be explained through particles colliding, and the practical papers tested salt preparation, ion tests and graph work. Stronger scripts used exact technical terms, showed each step and rounded only at the end. Weaker scripts named products when an observation was asked for, mixed up the three kinds of formula, put electrons on the wrong side of half-equations and stayed vague on environmental and safety points. The report comes back again and again to reading the whole question, stem included.

Where marks were lost:

• Paper 11: not seeing that both gases are used up in a fuel cell; mixing up the ammonium and nitrate tests.
• Paper 12: forgetting an equilibrium never completes; not knowing amphoteric oxides also react with alkalis.
• Papers 21 and 22: inverted mole ratios, early rounding, and the water in a hydrated salt’s molar mass handled wrongly.
• Papers 21 and 22: electrons on the wrong side of half-equations; oxidation numbers written as charges; O–H bonds missing.
• Paper 22: product names or equations given where an observation was wanted.
• Papers 32 and 42: awkward graph scales and dot-to-dot lines; universal indicator for a titration; a diluted solution made stronger.

Grade thresholds – June 2026

Components	Max	A*	A	B	C	D	E
11, 21, 31	200	160	129	98	67	56	46
11, 21, 41	200	164	133	102	71	58	45
12, 22, 32	200	164	131	98	65	56	48
12, 22, 42	200	164	131	98	65	55	45

Not shown: 1 further route(s) in the official table (staged entries that carry marks from an earlier series, or other special routes). See the official document.

Official documents: past papers, mark schemes and examiner report

November 2025

This series put mole calculations first, especially those using the Avogadro constant, standard form and gas volumes. Ionic half-equations, bonding in metals and halogens, equilibrium and rate, polymers and environmental chemistry also featured. The practical papers used a thermometric neutralisation with a graph, ion tests on an acidic solution, and a plan comparing energy released per gram. Stronger scripts showed every step, gave the requested significant figures and explained from the data or diagram supplied. Weaker scripts stated answers without reasons, used terms loosely, repeated the stem and left harder parts blank. They also lacked the observations that only hands-on practical work gives.

Where marks were lost:

• Paper 11: stopping a particle count at molecules instead of atoms; solubility rules; sacrificial protection.
• Paper 12: assuming every noble gas has eight outer electrons; gas-volume problems with one gas in excess.
• Paper 21: not using the pathway diagram to explain an endothermic change; halogens written as atoms in half-equations.
• Paper 22: relative atomic mass as a simple mean; colour given to the transition metal instead of its compounds.
• Papers 31 and 32: temperature change worked out from the previous reading, not the initial one; in Paper 31, chlorine for chloride.
• Papers 41 and 42: “gas produced” as an observation; masks instead of a fume cupboard; concentration per cm³.

Grade thresholds – November 2025

Components	Max	A*	A	B	C	D	E
11, 21, 31	200	173	146	113	80	64	49
11, 21, 41	200	172	144	110	77	61	46
12, 22, 32	200	170	141	108	75	61	48
12, 22, 42	200	170	140	105	71	57	44

Official documents: past papers, mark schemes and examiner report

June 2025

This series focused on quantitative work, electrolysis, energetics and organic chemistry. The practical papers tested titration handling, flame-test technique and a plan to separate and purify a mixture of solids. The Paper 21 report picks out organic chemistry and equation writing as particularly hard, with redox for specific species and precise collision theory not far behind. Stronger scripts showed every step, checked each formula before balancing, and answered exactly what was asked, such as a set number of significant figures. Weaker scripts repeated the stem, gave vague observations, confused chemicals with similar names and missed information given in the question.

Where marks were lost:

• Paper 11: ignoring excess gas left over in volume problems; choosing distillation to purify a solid.
• Paper 12: treating particle data for an ion as if it were an atom; missing branched isomers.
• Paper 21: graphite’s conductivity not linked to mobile delocalised electrons; using Ar where Mr was needed.
• Paper 22: intermolecular forces for a giant covalent structure; “more collisions” instead of more successful ones.
• Papers 32 and 42: luminous flames in flame tests; washing taken as proof of purity; in Paper 32, titres not to one decimal place.
• Paper 41: halogen displacement treated as a silver nitrate test; mole ratios in back-titrations.

Grade thresholds – June 2025

Components	Max	A*	A	B	C	D	E
11, 21, 31	200	169	139	105	72	60	48
11, 21, 41	200	169	138	105	72	59	47
12, 22, 32	200	170	140	105	71	59	47
12, 22, 42	200	169	139	105	71	58	46

Official documents: past papers, mark schemes and examiner report

November 2024

This series covered iron extraction and transition elements, electrolysis and half-equations, homologous series and organic structures, polymers and ester linkages, rate through collision frequency, equilibrium and pressure, and mole and limiting-reagent calculations. The practical papers centred on titration calculations and ion tests. Stronger scripts laid out working clearly, followed instructions on significant figures and command words, and drew structures with correct valencies. Weaker scripts struggled with terminology, ionic equations, energy profile diagrams, salt preparation and flame tests. They often answered from theory instead of from practical experience.

Where marks were lost:

• Papers 11 and 12: deducing ionic formulae without balancing charges; thinking ionic solids conduct by electrons.
• Papers 21 and 22: blast furnace chemistry, often left blank; anode half-equations reversed.
• Papers 21 and 22: carbon drawn with three or five bonds; ester and polymer linkages with extra atoms.
• Papers 21 and 22: heating to dryness in crystallisation; enthalpy arrows double-headed or pointing up.
• Papers 31 and 32: “best” titres chosen by smallest volume, not closest agreement; all titres averaged.
• Papers 41 and 42: naming products instead of describing them; reading a burette from the wrong end.

Grade thresholds – November 2024

Components	Max	A*	A	B	C	D	E
11, 21, 31	200	170	140	107	74	61	48
11, 21, 41	200	169	139	105	72	58	45
12, 22, 32	200	170	141	109	78	65	52
12, 22, 42	200	170	140	107	75	61	48

Official documents: past papers, mark schemes and examiner report

June 2024

This series leaned on mole and gas-volume calculations, energy profile diagrams, collision theory, equilibrium position, ionic bonding and redox at particle level, organic naming and displayed formulae. Practical work centred on temperature changes, flame tests and ion tests. Stronger scripts showed full working, named particles precisely as atoms, molecules or ions, and spotted key conditions in the stem such as excess reagent or required significant figures. Weaker scripts found organic chemistry hard, wrote formulae that could never balance, said the reaction moves when it is the equilibrium position that shifts, and showed little hands-on practical experience.

Where marks were lost:

• Papers 11 and 12: counting molecules when ions or total atoms were needed; thinking an endothermic reaction warms the mixture.
• Papers 21 and 22: wrong formulae for hydroxides and nitrates; missing or wrong state symbols.
• Papers 21 and 22: exothermic changes explained without comparing bond breaking and bond making.
• Paper 32: missing that the temperature drifts back to room temperature; a sodium flame read as calcium.
• Paper 41: the initial burette reading not subtracted; a flame colour taken from the burning splint.

Grade thresholds – June 2024

Components	Max	A*	A	B	C	D	E
11, 21, 31	200	167	135	101	68	56	45
11, 21, 41	200	166	133	99	66	54	43
12, 21, 32	200	163	130	97	65	54	44
12, 21, 42	200	161	128	95	63	52	42
12, 22, 32	200	163	130	97	65	54	44
12, 22, 42	200	161	128	95	63	52	42

Official documents: past papers, mark schemes and examiner report

November 2023

This series drew on electrolysis, structure and bonding, rates and equilibrium, organic structures and salt preparation. Electrolysis products and ionic half-equations were poorly known on both theory papers. Bonding answers often mixed ideas that cannot go together, such as intermolecular forces inside a giant structure. In the multiple-choice papers, physical and chemical change, solubility rules and reaction stoichiometry caused trouble. Stronger scripts set out calculations clearly, kept rate apart from equilibrium and gave full observations, including a colourless solution forming. The practical papers shared salt-preparation plans and graphs needing two straight lines of best fit.

Where marks were lost:

• Paper 11: reactive electrodes treated as inert; thinking fuel cells burn their fuel.
• Paper 12: Group VII boiling points explained by covalent bond strength instead of intermolecular forces.
• Paper 21: rate explained without successful collisions; oxidation numbers given without a sign.
• Paper 22: diamond given intermolecular forces; equilibrium shifts without comparing moles of gas.
• Papers 31 and 32: one curve drawn where two straight lines were needed (Paper 31); salt plans without filtration or drying (Paper 32).
• Paper 42: gloves instead of a fume cupboard for a toxic gas; silver nitrate for the sulfate test.

Grade thresholds – November 2023

Components	Max	A*	A	B	C	D	E
11, 21, 31	200	164	134	104	75	63	52
11, 21, 41	200	163	133	103	73	61	50
12, 22, 32	200	169	139	108	77	64	52
12, 22, 42	200	168	137	105	74	61	49

Official documents: past papers, mark schemes and examiner report

June 2023

The theory papers leaned on equilibrium, rates, energy-level diagrams, bond-energy sums, electrolysis and organic structures; the Paper 21 report notes this was the first exam with every question compulsory. The report’s main complaint is that weaker scripts blurred equilibrium with rate, confused how often particles collide with whether the collisions succeed, and gave a name where a formula was wanted, or the reverse. Describing what is seen, ionic half-equations and displayed formulae were weak. In Paper 11, the questions on transition elements, metals and alloys went badly. Stronger practical scripts recorded titration data to the right precision, used the qualitative analysis notes and covered every bullet of the plan.

Where marks were lost:

• Paper 11: activation energy treated as a maximum, not a minimum; cooling an exothermic equilibrium thought to cut the yield.
• Paper 12: naming and drawing esters; thinking alkenes do not burn.
• Paper 21: equilibrium described as equal, not unchanging, concentrations; energy-level arrows reversed.
• Paper 22: rate questions answered with equilibrium ideas; greenhouse effect confused with ozone depletion.
• Paper 32: burette readings to the wrong precision; plans that ignored the limit on which chemicals to use.
• Paper 41: repeat titrations justified “to get a mean” rather than for consistency; the nitrate test used for ammonium.

Grade thresholds – June 2023

Components	Max	A*	A	B	C	D	E
11, 21, 31	200	166	133	100	67	57	47
11, 21, 41	200	164	131	98	65	55	46
12, 22, 32	200	167	134	100	67	57	47
12, 22, 42	200	166	132	98	65	55	46

Official documents: past papers, mark schemes and examiner report

How to use this page

1. Find your gaps first. Take the free 5070 all-topics diagnostic (other subjects are on the diagnostics index) and tick off the O Level Chemistry checklist.
2. Sit a full paper under timed conditions. Download it from Cambridge’s past-papers page. Check the exam calendar so your practice matches the order of your real papers.
3. Mark it with the official mark scheme. Be strict about observations, units and significant figures. Check what each command word needs on our command words page.
4. Read the notes for that series above, then the bullets in “What examiners keep saying”. Tick each mistake you made.
5. Fix the topic. Use the resources on the O Level Chemistry hub and drill the weak area in the 5070 self-check question bank.
6. Re-test. Sit a paper from a different series a week later and compare. For June 2026 thresholds on our flagship syllabuses, see grade thresholds.
7. Want a teacher to mark your answers? Book a free trial lesson.

About these notes

These notes come from Cambridge’s grade-threshold tables and Principal Examiner Reports for Teachers for June 2023, November 2023, June 2024, November 2024, June 2025, November 2025 and June 2026, written in our own words. Thresholds change every series and must never be used to predict future ones. If you spot an error, please report a correction.