Cambridge IAS-Level · Analysis & Prediction

2023 Cambridge IAS-Level Chemistry (9701) Past Paper Analysis

A comprehensive analysis of the Cambridge International AS Level Chemistry (9701) May/June 2023 series (Paper 12, Paper 22, and Paper 32). This series features a balanced distribution of physical, inorganic, and organic chemistry topics, demanding high precision in calculations, organic reaction mechanisms, and qualitative observations.

Updated: 12 Jun 2026

Analysis Sample paper

Difficulty 3.6/5

Total marks

140

Duration

270 mins

Most tested

Stoichiometry and Practical Titration Calculations

Paper breakdown

Paper 12 (Multiple Choice): 40 marks · 75 minsPaper 22 (AS Level Structured Questions): 60 marks · 75 minsPaper 32 (Advanced Practical Skills 2): 40 marks · 120 mins

Top chapters

Atoms, molecules and stoichiometry · 22 marksGroup 2 · 15 marksChemical Periodicity and Qualitative Analysis · 15 marksAlkenes · 12 marks

May/June 2023 Series Difficulty Verdict

The May/June 2023 papers for AS Level Chemistry present a moderate-to-high challenge, earning a 3.6 out of 5 difficulty rating. While the papers do not deviate drastically from the syllabus core, they demand impeccable precision in calculation formatting, chemical nomenclature, and mechanistic drawings. Paper 12 (Multiple Choice) contains several highly discriminating questions on gas behaviour and organic reaction products. Paper 22 features demanding mechanism drawing questions that tested even the strongest candidates, while Paper 32 (Practical) requires rigorous data recording and meticulous attention to qualitative observation vocabulary.

Where the Marks are Distributed

A substantial portion of the marks in this series sits in Atoms, molecules and stoichiometry (amounting to 22 marks), driven by the Paper 32 titration question and chlorine concentration determination in Paper 22. Inorganic chemistry remains a massive pillar, with Group 2 and Period 3 trends (such as oxidation states, chloride reactions with water, and carbonate thermal stabilities) contributing around 25 marks across the papers. Within Organic Chemistry, the spotlight is on Alkenes (12 marks) and Isomerism (9 marks), specifically surrounding the hydration of ethene/propene, carbocation stability, and stereoisomerism prediction.

Examiner Pitfalls & Candidate Errors

The examiner reports across the components highlight several recurring issues where candidates unnecessarily drop marks:

Calculation Rounding: Early rounding in multi-step calculations (particularly in stoichiometry and calorimetry) frequently leads to compounded rounding errors. Candidates should keep full calculator values until the final step.
Mechanism Accuracy: In drawing curly arrows (e.g., nucleophilic addition to carbonyls or electrophilic addition to alkenes), candidates often start arrows from atoms instead of a specific bond or lone pair, or fail to show intermediate charges.
State Symbols & Ionic Equations: Marks are frequently lost for omitting state symbols when explicitly requested, or for writing molecular equations instead of simplified ionic equations.
Observation Terminology: In qualitative tests, outdated descriptors like 'milky' or 'cloudy' for the limewater test are no longer accepted. The term white precipitate must be used.

Revision Strategy & Predictions

To maximize study ROI, students must focus heavily on mastering stoichiometry and redox calculations as they form the backbone of both Paper 2 and Paper 3. Practice drawing mechanisms from blank sheets, ensuring curly arrows begin and end at precise coordinates (lone pairs to electron-deficient centres). For future sets, expect a strong recurrence of SN1 and SN2 mechanisms and their respective transition states, which were underrepresented in the structured questions here. Furthermore, physical trends in period 3 oxides and the exact preparation conditions for various organic compounds should be memorized thoroughly.

Charts

Marks by chapter

See where the marks were concentrated so revision time goes to the highest-value topics.

Question type mix

Compare the mark share of each paper section and question type.

multipleChoice40 marks · 40 questions
structured60 marks · 5 questions
practical40 marks · 3 questions

Mark accessibility

Estimate which marks were basic, mid-level, or high-difficulty.

79%within easy or medium reach

easy: 45 marksmedium: 65 markshard: 30 marks

Difficulty trend

Compare difficulty across recent years.

Command word frequency

Spot common command words so answers match the expected response style.

Skill weighting

Shows the skill mix this paper tested most heavily.

Study ROI

Bigger bubbles recur more often; higher bubbles carry more marks, helping you rank revision priorities.

Reacting masses and volumes

22 marks · Difficulty 2.5 · recurrence 95%

Group 2 Metal compounds

15 marks · Difficulty 2.8 · recurrence 85%

Alkenes & Carbocation Stability

12 marks · Difficulty 3.2 · recurrence 90%

Structural Isomerism & Stereoisomerism

9 marks · Difficulty 3.5 · recurrence 80%

Period 3 periodicity and oxide trends

10 marks · Difficulty 3 · recurrence 85%

Time vs marks

Compare marks with suggested time allocation to plan exam pacing.

marksmins

Next-year prediction

Topics worth watching next year, with the reason shown directly below each bar.

Halogenoalkanes substitution mechanisms (SN1 vs SN2)90%

Briefly tested in Paper 12 MCQ but absent in Paper 22. Expect upcoming structured questions asking for transition states, chiral centers, and rate-determining steps.

Boltzmann distribution curves with temperature shifts85%

Tested in MCQ but not as a full structured question in Paper 22. Drawing shifted curves at higher/lower temperatures is a frequent focus.

Entropy and Gibbs Free Energy (for A Level transition)80%

Feasibility reactions and the temperature dependence of Gibbs free energy are highly recurrent discriminators in subsequent paper components.

Cumulative marks ladder

The line is your running mark total question by question; dashed lines are the estimated grade cut-offs. See which question the line crosses your target grade at, so you know how far you must answer cleanly and which questions decide a band.

Topic-year heatmap

Compare topic weight by year to spot recurring and returning areas.

Jun 2023 (V1)

Jun 2023 (V2)

Atomic structure (Physical chemistry (AS Level))

Electrons, energy levels and atomic orbitals

Ionisation energy

Particles in the atom and atomic radius

Atoms, molecules and stoichiometry (Physical chemistry (AS Level))

Relative masses of atoms and molecules

Reacting masses and volumes

The gaseous state: ideal and real gases and pV = nRT

Formulas

Shapes of molecules

Examiner insights

Official report

Common pitfalls

Writing unbalanced chemical equations or omitting gas/state symbols when specifically requested in the prompt.
Early rounding in multi-step calculations (e.g., in stoichiometry or enthalpy cycles) leading to compounding errors in the final significant figures.
Drawing curly arrows incorrectly in mechanisms, either starting them from an atom instead of a lone pair/bond, or pointing them to incorrect destinations.
Failing to divide titres by 1000 to convert cubic centimeters into decimeters during concentration calculations in Paper 3.

Misconceptions

Believing that the addition of dilute acid to a thermal decomposition residue can prove complete decomposition, failing to realize that the acid will also react with the metal oxide product.
Confusing physical trends (e.g., atomic radius) with chemical trends (e.g., thermal stability of carbonates) across Period 3 and Group 2.
Assuming that a neutralisation reaction is endothermic or always requires energy input.
Confusing 'nucleon number' with 'neutron number', or 'isotope' with 'isomer'.

Where marks are lost

Failing to state the observation of 'white precipitate' for the limewater test, with candidates still using outdated terms like 'milky' or 'cloudy' which are no longer accepted.
Failing to include necessary conditions like 'heat under reflux' for complete organic oxidations, or the solvent (e.g., ethanol) for substitution reactions.
Omission of square brackets when writing the formula for pH calculations or equilibrium constant expressions.
Inability to deduce the correct formula of calcium salts in organic synthesis, often assuming calcium has a valency of one.

Estimated grade cut-off

Updated: 12 Jun 2026

Source: Cambridge International component thresholds (AS aggregate, derived)

Level	Mark	Percentage
A	88/140	63%
B	70/140	50%
C	56/140	40%
D	43/140	31%
E	30/140	21%

Estimated cut-offs from Cambridge International component thresholds (AS aggregate, derived); may differ from the official boundaries.

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