AQA IAS-Level · Analysis & Prediction

2023 AQA IAS-Level Chemistry (9620) Past Paper Analysis

A highly rigorous examination suite across Units 1, 2, and 3, featuring a strong emphasis on multi-step calculations, graphical analyses, and complex inorganic coordination structures alongside demanding organic reaction mechanisms.

Updated: 12 Jun 2026

Analysis Sample paper

Difficulty 4.1/5

Total marks

220

Duration

270 mins

Most tested

Physical Chemistry Calculations and Thermodynamics

Paper breakdown

Unit 1: Inorganic 1 and Physical 1: 70 marks · 90 minsUnit 2: Organic 1 and Physical 1: 70 marks · 90 minsUnit 3: Inorganic 2 and Physical 2: 80 marks · 90 mins

Top chapters

Energetics · 31 marksTransition Metals, Complexes and Spectroscopy · 25 marksHalogenoalkanes · 23 marks

Executive Examiner Summary

The June 2023 Oxford AQA International AS and A-Level Chemistry examination represents a challenging assessment. Across all three units, examiners pushed beyond rote recall to test high-level application, particularly in physical and analytical chemistry. High-tariff mathematical calculations, graphical work (including extrapolation and gradient calculations), and precise organic mechanisms were major deciders for top grades.

Where the Marks Were Won and Lost

A significant portion of marks was allocated to mathematical fluency. In Unit 1, the 4-mark Time of Flight (TOF) mass spectrometry velocity calculation and the 4-mark ideal gas law calculation required seamless unit conversions. In Unit 2, the 5-mark calculation of starting material in an equilibrium mixture tested algebra under pressure. Unit 3 introduced a demanding 5-mark buffer solution calculation alongside a 5-mark redox titration calculation involving manganate(VII) and ethanedioate.

Students performed well on standard recall items, such as naming the strongest intermolecular force in ice and defining standard enthalpy of formation. However, performance plummeted on drawing coordinate bonds in transition metal complexes and illustrating organic mechanisms (such as the acid-catalysed elimination of butan-1-ol and the reaction of epoxyethane with water).

Examiner Pitfalls & Mistakes to Avoid

Unit Conversion Blunders: In the TOF calculation, many candidates failed to convert the mass of the \( ^{207}\text{Pb}^+ \) ion from grams to kilograms (forgetting to divide by 1000 after dividing by Avogadro's constant), rendering their subsequent kinetic energy substitutions incorrect.
Sloppy Curly Arrows: Organic mechanism diagrams lost easy marks. Arrows must start precisely from a *lone pair* or a *covalent bond* and point directly to the electrophilic centre. Showing arrows originating from carbon atoms instead of bonds was a common error.
State Symbols: In Born-Haber cycles and ionisation energy equations, the omission of state symbols (such as \( \text{S(g)} \rightarrow \text{S}^+\text{(g)} + \text{e}^- \)) resulted in immediate mark loss.
Ligand Connectivity: In transition metal complexes, coordinate bonds from water ligands must clearly point from the oxygen atom (\( \text{O}-\text{Cr} \)) rather than the hydrogen atoms.

Preparation Strategy & Future Predictions

To master upcoming series, students must build rigorous mathematical checklists: always convert volumes to \( \text{dm}^3 \) or \( \text{m}^3 \) depending on the equation, and double-check key physical constants. Future exams are highly likely to test areas that were quieter in this series, such as Group 2 solubility trends and detailed Kinetics rate equations which were underrepresented here. Dedicating revision time to drawing 3D stereoisomers (cis/trans and optical) of octahedral complexes will yield excellent returns.

Charts

Marks by chapter

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Question type mix

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

Calculations and Multi-step Equations52 marks · 12 questions
Mechanisms and Structure Drawings22 marks · 8 questions
Short Answer Explain/Describe68 marks · 28 questions
Recall and Matching/Ticks78 marks · 25 questions

Mark accessibility

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74%within easy or medium reach

easy: 74 marksmedium: 88 markshard: 58 marks

Difficulty trend

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Command word frequency

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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.

Period 3 Trends and Properties

23 marks · Difficulty 2.5 · recurrence 5%

Halogenoalkane Nucleophilic Substitution & Elimination Mechanisms

23 marks · Difficulty 3.2 · recurrence 5%

Energetics (Born-Haber & Cycles)

31 marks · Difficulty 3.8 · recurrence 4%

Group 7 Halogen Trends & Redox

17 marks · Difficulty 2.8 · recurrence 4%

Time vs marks

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marksmins

Next-year prediction

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

Group 2 Metal Hydroxides/Sulfates Solubility Trends85%

Group 2 is heavily featured in the syllabus but had almost no core descriptive chemistry questions in this series; standard solubility trend analysis is highly likely to appear in the next cycle.

Kinetics Rate Equations and Arrhenius Calculations78%

Syllabus Kinetics details like reaction mechanisms linked to rate determining steps and Arrhenius calculations were absent in CH03, making them prime candidates for the next sitting.

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

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Jan 2023

Jun 2023

Amount of substance (Physical chemistry)

Thermodynamics (Physical chemistry)

Periodicity (Inorganic chemistry)

Acids, bases and pH (Physical chemistry)

Bonding (Physical chemistry)

Energetics (Physical chemistry)

Group 7(17), the halogens (Inorganic chemistry)

Reactions of metal ions in aqueous solution (Inorganic chemistry)

Halogenoalkanes (Organic chemistry)

Transition metals and coordination complexes (Inorganic chemistry)

Examiner insights

Official report

Common pitfalls

Incorrect TOF mass calculation: failing to convert mass from g/mol to kg/ion (needed division by Avogadro and then division by 1000).
Mechanistic arrow origins: drawing arrows starting from hydrogen atoms rather than adjacent C-H bonds in elimination reactions.
Born-Haber cycles: leaving out required state symbols (e.g., (g) for gaseous ions) which incurs instant penalties.
Ligand drawing connectivity: misdirecting the arrow/line in dative bonds, starting from H rather than the O lone pair in aquated complexes.

Misconceptions

Assuming adding a catalyst will change the final value of the equilibrium constant (Kc).
Believing that transition metals have incomplete d-orbitals in all ionic states (e.g., Cu+ is actually 3d10 and thus has no d-d transition capability).
Assuming that standard state for magnesium is liquid (Mg(l)) when standard enthalpy of formation is calculated.

Where marks are lost

In pH calculations of buffer mixtures where students fail to apply volume division for concentrations of salt and acid in Ka expression.
In drawing stereoisomers of octahedral complexes, especially missing the positive charge on the overall bracketed ions.
When describing the action of a catalyst, candidates fail to explain that impurities cause poisoning of the catalyst by blocking active sites.

Estimated grade cut-off

Updated: 12 Jun 2026

Source: Oxford AQA International grade boundaries (UMS)

Level	Mark	Percentage
A	—	80%
B	—	70%
C	—	60%
D	—	50%
E	—	40%

Official grade boundaries published by Oxford AQA International grade boundaries (UMS).

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