Verbatim quotes from 4 official Cambridge examiner reports (2023–2025). Every quote is attributable to a specific paper and session — these are the things Cambridge markers flag year after year.

Confusing equilibrium with rate of reaction

Candidates confused equilibrium concepts with rate of reaction, often explaining shifts in equilibrium using collision theory rather than Le Chatelier's principle.

— Cambridge examiner, 5070 Paper 2, May/June 2023

'Produces a gas' is not an observation

Candidates stated that a gas was produced rather than describing the observable evidence such as effervescence or bubbling.

— Cambridge examiner, 5070 Paper 2, May/June 2023

Drawing organic structures with wrong valencies

Many candidates drew organic structures with incorrect valencies, commonly showing carbon with five bonds or omitting hydrogen atoms, resulting in invalid structural formulae.

— Cambridge examiner, 5070 Paper 2, May/June 2023

See how to avoid these in the Chemistry 5070 exam guide

Avoid these

Most Common Mistakes — Chemistry (5070)

Based on analysis of 4 official Cambridge examiner reports (2023, 2024, 2025). Avoid these errors to maximise your marks.

Confusing equilibrium with rate of reaction — using collision theory for equilibrium

Paper 2 · Widespread in Paper 2, 2023

'Produces a gas' is not an observation — must say effervescence/bubbling

Paper 2, Paper 3, Paper 4 · Seen across Papers 2, 3, and 4 in 2023

Drawing organic structures with wrong valencies — missing hydrogens, pentavalent carbon

Paper 2 · Common in organic chemistry questions, Paper 2, 2023

Energy profile diagrams — wrong axes, activation energy drawn in wrong direction

Paper 2 · Recurring in Paper 2, 2023

Greenhouse effect confused with ozone depletion

Paper 2 · Seen in environmental chemistry questions, Paper 2, 2023

Focus your revision

Topics Students Struggle With Most

Equilibrium vs rate

Candidates used collision theory to explain equilibrium shifts instead of applying Le Chatelier's principle, confusing two distinct concepts.

Paper 2

Organic structure drawing

Pentavalent carbon and missing hydrogen atoms were common, showing weak understanding of bonding rules in organic molecules.

Paper 2

Energy profiles

Incorrect axis labels and activation energy drawn from the wrong baseline were frequent errors in energy profile diagram questions.

Paper 2

Electrolysis

Products at electrodes were frequently reversed, and half-equations were written with electrons on the wrong side.

Paper 2

Greenhouse effect

Confused with ozone depletion — candidates attributed infrared trapping to CFCs or claimed CO₂ destroys the ozone layer.

Paper 2

Group I properties

Candidates struggled to describe trends in Group I reactivity, often reversing the trend or failing to link it to atomic radius and electron shielding.

Paper 2

Flame colours

Flame test colours for metal ions were frequently confused or incorrect, particularly for sodium (yellow), potassium (lilac), and copper (blue-green).

Paper 2, Paper 3, Paper 4

Mole calculations with Avogadro

Candidates made errors converting between moles and number of particles, often dividing by Avogadro's number instead of multiplying.

Paper 2

Redox: oxidation/reduction of species within a compound

Candidates routinely stated 'the compound is oxidised' rather than identifying which atom or ion changed oxidation state. Some also reversed the direction of oxidation and reduction.

Paper 2

Polymerisation displayed formulae and repeat units

When asked to draw a polymer repeat unit, candidates included side chains inside the carbon backbone, drew only one repeat unit without continuation bonds, or copied poly(ethene) for unrelated monomers.

Paper 2

Manufacture of organic products (vinegar from ethanoic acid)

Few candidates appreciated that ethanoic acid is manufactured by the bacterial oxidation of ethanol. Many incorrectly cited potassium manganate(VII) as the industrial oxidising agent.

Paper 2

Collision theory — frequency vs success of collisions

Candidates wrote 'more collisions' or 'higher kinetic energy' without linking these to specific factors (frequency increases with concentration/pressure, success increases with temperature or catalyst).

Paper 2

About

Chemistry (5070) — Cambridge O Level Full Archive 2002–2026

This page contains all 743 available papers for Cambridge O Level Chemistry (5070) — 47 exam sessions from 2002 to 2026. Each session includes question papers, mark schemes, and where available, examiner reports and grade threshold documents. All files are free to download as PDF — no account required.

Cambridge O Level Chemistry (5070) is examined through multiple paper components. Question papers are available in two or three variants per session (v1, v2, v3) — each variant is sat in a different time zone but covers the same syllabus content and is equivalent in difficulty. The paper number in the filename indicates which component: for example, 5070_qp_12 is Paper 1, Variant 2.

Mark schemes for 5070 show the exact marking points accepted by Cambridge examiners. Many questions have multiple acceptable phrasings — look for 'accept', 'allow', and 'credit' in the mark scheme to understand the full range of valid responses. Examiner reports (where available) reveal the most common errors made by the cohort and what top-band answers looked like, making them essential reading before the actual exam.

The most effective way to use this archive is to attempt past papers under timed exam conditions, then analyse your mark scheme results by component. Track which paper components and question types you score lowest on — this tells you exactly where to focus revision. Grade threshold documents show the minimum mark needed for each grade in that specific session, which helps calibrate how your practice scores translate to actual grades.

Same subject

Chemistry 5070 at other levels

Cambridge IGCSE Chemistry

Subject code: 0620

Cambridge AS & A Level Chemistry

Subject code: 9701

FAQs

Questions, answered.

You can download all Cambridge Chemistry 5070 past papers right here on PapersDaddy. We have 47 exam sessions from 2002–2026 — including question papers, mark schemes, examiner reports, and grade thresholds for 5070. Click any session below to view and download PDFs.

Yes! Every Cambridge O Level Chemistry (5070) exam session includes the corresponding mark scheme alongside the question paper. Mark schemes show exactly how marks are allocated, helping you understand what examiners look for in top-scoring answers.

Start with recent 5070 papers (2025–2023) to understand current trends. Practice under timed conditions, then mark yourself using the mark scheme. Read examiner reports to learn common mistakes. For targeted revision, use Chemistry 5070 topical past papers to focus on specific topics.

We have Cambridge O Level Chemistry (5070) papers from May/June, October/November, and March sessions (where applicable), covering 2002–2026. That's 47 exam sessions in total.