Cambridge International AS Level

Chemistry 9701

Physical, inorganic and organic chemistry, extending at A Level to energetics, transition elements and spectroscopy.

Exam year

Syllabus version: 2025–2027 syllabusChecked against the Cambridge syllabusExam year 2027 is covered by the 2025–2027 syllabus.

Subject review complete (19 Oct 2026). All 31 AS Level Chemistry questions were re-solved and checked against the syllabus and Cambridge mark-scheme conventions, and their auto-marking was tested with correct and incorrect answers.

Paper 1 Multiple Choice31%
Paper 2 AS Level Structured Questions46%
Paper 3 Advanced Practical Skills23%

Original questions31

Topics covered17/23

Papers3

Mock papers5

What is assessed

3 components. Question formats: multiple choice, structured, practical.

Paper 1 Multiple ChoiceAS

1 h 15 min40 marks31% of AS

40 four-option multiple-choice questions on AS Level content, testing AO1 and AO2 (50% each).

What the paper looks like

40 independent four-option questions (A–D), 1 mark each, about one minute per question. Mixes recall with data handling: short calculations (moles, gas volumes, pV = nRT, bond energies), interpreting graphs/energy diagrams, structures and reaction schemes. Some items ask how many of several statements or species fit a description. Calculator allowed; Periodic Table and constants given.

Multiple choicePeriodic Table and important values/constants printed in the paper

Checked against the Cambridge syllabus

Paper 2 AS Level Structured QuestionsAS

1 h 15 min60 marks46% of AS

Structured questions on AS Level content testing AO1 and AO2, answered in the spaces on the paper.

What the paper looks like

Typically five or six structured questions, each 6–14 marks, split into (a)(i)… parts of 1–4 marks. Command words: define, state, explain, deduce, calculate, draw, suggest. Expect definitions, equations with state symbols, dot-and-cross diagrams, mechanisms with curly arrows, short calculations with working shown, and organic reaction schemes with unknown compounds to identify.

StructuredPeriodic Table and important values/constants printed in the paper

Checked against the Cambridge syllabus

Paper 3 Advanced Practical SkillsAS

2 h40 marks23% of AS

Laboratory practical test (AO3): two or three questions, one qualitative observational problem plus quantitative work such as a titration or measurement of time, temperature, mass or gas volume.

What the paper looks like

Two or three practical questions (about 13–14 marks each) done in the laboratory: a titration or measurement exercise (time, temperature, mass or gas volume) with a table of results, a calculation sequence and an evaluation of errors, plus a qualitative analysis question using the supplied notes. Credit for accuracy is judged against the supervisor's results.

PracticalStructuredPeriodic Table and Qualitative analysis notes printed in the paper

Checked against the Cambridge syllabus

Assessment overview

From the 2025–2027 syllabus. Checked against the Cambridge syllabus

AS Level

Paper 1Paper 2Paper 3

Assessment objective	AS Level weighting
AO1 Knowledge and understanding	40%
AO2 Handling, applying and evaluating information	40%
AO3 Experimental skills and investigations	20%

Changes in this syllabus version

Version 1 (published September 2022): reagents updated in learning outcomes 15.1(c) and 16.2(b).
Assessment structure (five papers, marks, durations and weightings) unchanged from the 2022–2024 syllabus.
Textbooks endorsed for examination from 2022 remain suitable.

Command words used in Chemistry papers (22)

Analyse: examine in detail to show meaning, identify elements and how they relate
Calculate: work out a value from given facts, figures or information
Compare: identify or comment on similarities and/or differences
Consider: review given information and respond to it
Contrast: identify or comment on differences
Deduce: reach a conclusion from the information available
Define: give a precise meaning
Demonstrate: show how, or give an example
Describe: state the points of a topic or give its characteristics and main features
Determine: establish an answer using the information available
Discuss: write about issue(s) or topic(s) in depth in a structured way
Evaluate: judge or calculate the quality, importance, amount or value of something
Examine: investigate closely and in detail
Explain: give reasons or purposes, make relationships clear and support with evidence (why and/or how)
Give: produce an answer from a given source or from recall
Identify: name, select or recognise
Justify: support a case with evidence or argument
Predict: suggest what may happen based on available information
Show (that): provide structured evidence leading to a given result
Sketch: make a simple (freehand) drawing showing the key features
State: express in clear terms
Suggest: apply knowledge to a situation with a range of valid responses to make proposals or considerations

Examiner guidance from recent reports (14)

Atomic structure. Learn definitions word-for-word: first ionisation energy needs 'one mole', 'gaseous atoms' and 'one mole of gaseous 1+ ions'. When explaining IE dips (Mg→Al, P→S) name the specific sub-shell or the spin-pair repulsion in a doubly occupied p orbital, not just 'more stable'.

Atoms, molecules and stoichiometry. Write chemical formulas carefully (O2 not O, Na2SO4 not NaSO4). Keep intermediate values to at least 3–4 significant figures and only round the final answer; premature rounding is a frequent cause of lost accuracy marks.

Chemical bonding. A covalent bond is the electrostatic attraction between two nuclei and a shared pair of electrons — 'sharing electrons' alone is not enough. For shapes, state the number of bonding pairs and lone pairs and that lone pairs repel more strongly before giving the angle.

Chemical energetics. In q = mcΔT use the mass of the solution (volume × 1.0 g cm⁻³), not the mass of solid added, then divide by moles of the limiting reagent and convert J to kJ. Always include the sign of ΔH.

Equilibria. Le Chatelier answers need three steps: what changes, which direction the equilibrium shifts, and why (e.g. fewer gas moles, endothermic direction). Remember only temperature changes the value of K; a catalyst changes neither K nor position.

Reaction kinetics. When sketching Boltzmann distributions at higher temperature, keep the curve starting at the origin, make the peak lower and further right, and never let it touch the energy axis at high energy. Link explanations to 'more molecules with E ≥ Ea' and 'more frequent effective collisions'.

Hydrocarbons. Curly arrows must start from a bond or lone pair and end precisely on an atom or between atoms. In electrophilic addition show the partial charges on Br–Br, the carbocation and the attack by Br⁻.

Halogen compounds. Reactivity of halogenoalkanes depends on C–X bond strength, not bond polarity — state that C–I is the weakest bond so iodoalkanes react fastest. For SN1 versus SN2, link the mechanism to primary/tertiary structure and carbocation stability.

Practical skills (Paper 3). Draw a results table before starting, record every burette reading to 0.05 cm³, and choose only concordant titres (within 0.10 cm³) for the mean. Use the given qualitative analysis notes and describe colours and precipitates precisely, naming reagents in full.

Chemical energetics (A Level). In ΔG = ΔH − TΔS convert ΔS from J K⁻¹ mol⁻¹ to kJ K⁻¹ mol⁻¹ and use T in kelvin (298 K, not 25). In Born–Haber cycles include electrons and state symbols and multiply atomisation and electron affinity by the number of atoms.

Equilibria (A Level). A buffer definition must mention resisting change in pH when small amounts of acid or alkali are added. In buffer calculations use the concentrations after mixing (or moles, since volume cancels), not the stock concentrations.

Reaction kinetics (A Level). Deduce each order by comparing two experiments where only one concentration changes, and state which experiments you used. Units of k follow from the overall order and the time unit in the data (s or min).

Chemistry of transition elements. Explain colour as: ligands split d orbitals, visible light of a particular frequency is absorbed as an electron is promoted, and the complementary colour is seen. Ions with d⁰ or full d¹⁰ configurations cannot undergo d–d transitions.

Planning, analysis and evaluation (Paper 5). Read the introduction carefully — it supplies the chemistry you need. Take gradients from the line of best fit using points far apart rather than from data points, and give specific improvements (named apparatus, quantities) rather than vague 'repeat it'.

Topic map

Practice types

Free sample questions

Selenium has proton number 34. How many protons, neutrons and electrons are present in one 79Se2− ion?

Selenium has proton number 34. How many protons, neutrons and electrons are present in one ⁷⁹Se²⁻ ion?

34 protons, 45 neutrons, 32 electrons
34 protons, 45 neutrons, 36 electrons
34 protons, 79 neutrons, 36 electrons
36 protons, 45 neutrons, 34 electrons

Answer: B. 34 protons, 45 neutrons, 36 electrons

Protons = proton number = 34. Neutrons = nucleon number − proton number = 79 − 34 = 45. A 2− charge means two electrons gained, so electrons = 34 + 2 = 36.

Chromium has proton number 24. What is the ground-state electronic configuration of the Cr3+ ion?

Chromium has proton number 24. What is the ground-state electronic configuration of the Cr³⁺ ion?

1s²2s²2p⁶3s²3p⁶3d³
1s²2s²2p⁶3s²3p⁶3d¹4s²
1s²2s²2p⁶3s²3p⁶3d²4s¹
1s²2s²2p⁶3s²3p⁶3d⁴

Answer: A. 1s²2s²2p⁶3s²3p⁶3d³

The Cr atom is [Ar]3d⁵4s¹. When transition-element atoms form ions, 4s electrons are lost first, so Cr³⁺ loses the 4s electron and two 3d electrons: [Ar]3d³ (21 electrons). 3d⁴ would be Cr²⁺.

FAQs

Are these official 9701 past-paper questions?

No. They are original questions written to match the Chemistry syllabus topics. Official past papers are available to schools through Cambridge.

Why choose an exam year?

Cambridge updates syllabuses periodically. Your exam year selects the matching configuration so topics and components follow the right version.

How do AS and A Level differ here?

Both pathways share code 9701. AS pages include AS topics and components only; A Level pages add the A Level content and papers.

Is a calculator allowed?

In this configuration a scientific calculator is permitted for the listed papers. Check your syllabus for the exact rule.