1. Syllabus, topic list and paper structure
1a. Which syllabus
- First examined in 2022. These papers belong to the 9701 syllabus first examined in 2022 (2022–2024 version, then 2025–2027). AS topics are 1–22 and A Level topics 23–37.
- The syllabus document is not in the local folder. Everything below is inferred from the papers.
Evidence of the 2022 syllabus in the papers
- The papers regularly use content of the 2022 syllabus:
- sp/sp²/sp³ hybridisation and σ/π overlap;
- M+1 peaks to count carbon atoms;
- partial pressures and Kp in kPa;
- Kstab and Ksp;
- partition coefficients;
- electrophoresis and isoelectric points;
- proton and carbon-13 NMR (with D2O exchange and TMS).
- The MCQ order follows the syllabus in every session:
- Q1–15/16 are physical;
- Q16/17–24 are inorganic (Period 3, Group 2, Group 17, N & S);
- Q25–39 are organic;
- Q40 is always analysis (mass spectrometry 6 times, IR 3 times).
Visible changes between 2022–25 and 2026-MJ (all variant-2 papers)
- "Figure 1.1" replaces "Fig. 1.1". Fig. appears 16–50 times per session up to 2025-ON and 0 times in 2026. "Figure" appears 59 times in 2026.
- The standard symbol is now ⦵ (7 uses in 2026, none before).
- "London dispersion forces" appears in P1 2026 (Q22). Earlier papers say "instantaneous dipole–induced dipole".
- Partition coefficient (Kpc) appears for the first time in this sample: P4 2026 Q4, 6 marks. It may be a new emphasis or just rotation; the syllabus could not be checked.
- The structure is unchanged. Cover pages, durations and mark totals are identical from 2022 to 2026.
1b. Topics and subtopics used for tagging (27 topics)
The list follows the request (Physical / Inorganic / Organic / Analysis), with two additions:
- Atoms, molecules & stoichiometry (syllabus topic 2), which carries many marks;
- Practical skills, for P3/P5 skill marks.
AS and A Level parts of the same topic share one topic name; the subtopic shows the level (for example Rate equations & orders is A Level).
| Area | Topic | Subtopics used |
|---|---|---|
| Physical | Atomic structure | particles, isotopes & ions; electronic configuration; orbitals & sub-shells; ionisation energies; atomic & ionic radius |
| Physical | Atoms, molecules & stoichiometry | relative masses; mole calculations; reacting masses & gas volumes; empirical/molecular formula; water of crystallisation; equations & mole ratios; titration calculations; % yield |
| Physical | Chemical bonding | bonding types & properties; metallic bonding; giant covalent; dot-and-cross; dative bonds; VSEPR shapes; σ/π & hybridisation; intermolecular forces; hydrogen bonding |
| Physical | States of matter | ideal gas equation; ideal vs real gases; lattices; diffusion |
| Physical | Chemical energetics | definitions; Hess cycles; bond energies; calorimetry; reaction pathway diagrams |
| Physical | Chemical energetics (A Level) | lattice energy & Born–Haber; electron affinity; enthalpies of solution & hydration |
| Physical | Entropy & Gibbs free energy | entropy changes; ΔG & feasibility |
| Physical | Electrochemistry & redox | oxidation numbers & redox; balancing redox equations; electrolysis & Faraday; E° & cells; Nernst; ΔG–E°cell |
| Physical | Equilibria | dynamic equilibrium; Le Chatelier; Kc/Kp; industrial equilibria; Brønsted–Lowry; pH/Ka/Kw; buffers; Ksp & common ion; partition |
| Physical | Reaction kinetics | collision theory; Boltzmann & temperature; catalysis; rate measurement; rate equations & orders; half-life; mechanisms & RDS; homogeneous/heterogeneous catalysis |
| Inorganic | Periodicity (Period 3) | trends (radius, IE, electronegativity); structure & melting points; reactions with O2/Cl2; oxides & chlorides |
| Inorganic | Group 2 | reactions with water/O2; hydroxide & sulfate solubility; thermal decomposition; A Level solubility & thermal-stability explanations |
| Inorganic | Group 17 | halogen trends; halide tests & reactions with H2SO4; displacement; Cl2 with water/NaOH; water treatment |
| Inorganic | Nitrogen & sulfur | NH3/NH4+; NOx, smog & catalytic converters; SO2 & acid rain; nitric acid; N2 unreactivity |
| Inorganic | Transition elements | properties; d-orbitals & ion configurations; redox titrations (MnO4–, Cr2O7^2–) |
| Inorganic | Transition element complexes | ligands, shapes & coordination number; isomerism; colour & d-splitting; ligand exchange & Kstab |
| Organic | Organic introduction & isomerism | formulae; nomenclature & structural isomers; stereoisomerism (incl. A Level optical); mechanism terms |
| Organic | Hydrocarbons | free-radical substitution; cracking/combustion; electrophilic addition; KMnO4 oxidation; arenes (electrophilic substitution, side-chain oxidation) |
| Organic | Halogen compounds | reagents & conditions; SN1/SN2; elimination; preparation; halogenoarenes |
| Organic | Hydroxy compounds | alcohol oxidation, substitution, dehydration; phenol |
| Organic | Carbonyl compounds | HCN addition; 2,4-DNPH/Fehling's/Tollens'; tri-iodomethane |
| Organic | Carboxylic acids & derivatives | reactions; esters; LiAlH4 reductions; acyl chlorides; relative acidity |
| Organic | Nitrogen compounds | amines & nitriles; basicity; phenylamine & azo dyes; amides; amino acids, peptides & electrophoresis |
| Organic | Polymerisation | addition; condensation; degradability |
| Organic | Organic synthesis | distinguishing tests; multi-step routes; deducing structures from data |
| Analysis | Analytical techniques | mass spectrometry; IR; proton NMR; carbon-13 NMR; chromatography |
| Practical | Practical skills | planning, standard solutions, safety, variables; data processing, graphs, gradients, anomalies, % error, evaluation; titration, rates, thermochemistry, gas collection, qualitative analysis (P3) |
1c. Components, from the cover pages
The cover pages are identical from 2022 to 2026: same durations, same mark totals, all questions compulsory.
| Component | Level | Duration | Marks | Weight* | Format (variant 2) |
|---|---|---|---|---|---|
| P1 Multiple Choice | AS | 1 h 15 min | 40 | 31% AS / 15.4% A | 40 four-option MCQs in syllabus order; Q40 always analysis |
| P2 AS Level Structured Questions | AS | 1 h 15 min | 60 | 46% AS / 23.1% A | 3–6 questions of 5–22 marks (6, 3, 5, 4, 5, 4, 5, 4, 6 questions, 2022-MJ → 2026-MJ) |
| P3 Advanced Practical Skills | AS | 2 h | 40 | 23% AS / 11.5% A | always 3 questions of 9–18 marks: two quantitative experiments + one qualitative-analysis question |
| P4 A Level Structured Questions | A2 | 2 h | 100 | 38.5% A | 9 questions in 8 of 9 sessions (8 in 2024-ON), 5–20 marks each |
| P5 Planning, Analysis & Evaluation | A2 | 1 h 15 min | 30 | 11.5% A | always 2 questions (10–20 marks each), each built on one experiment |
*Weights are inferred from the grade-threshold files.
- AS is weighted to 130 marks: P1 40 + P2 60 + 0.75 × P3.
- Full A Level is weighted to 260 marks: AS 130 + P4 100 + P5 30, with P4 and P5 unscaled.
- Check (2026-MJ, route 12-22-33-42-52):
- A Level: the component A thresholds give 25 + 37 + 0.75 × 22 + 66 + 23 = 167.5, which matches the published A of 168.
- AS: 25 + 37 + 16.5 = 78.5, which matches the published A of 79.
Paper 3 sessions and variants
- May/June has 31–35; Oct/Nov has 31 and 33–36. Each variant is a different laboratory session with different experiments.
- 31/33/35/37 are titled "Advanced Practical Skills 1" and the others "…2".
New from 2025: a fourth variant (x4) of every written paper, plus Paper 3 codes 37 and 38
- The x4 papers are new papers, not copies. Word-sequence similarity with variants 1–3 is only 0.31–0.46 (shared boilerplate). Cover, duration and marks are the same.
- 37 and 38 are copies of an existing practical from the same session (similarity 1.00):
- in May/June 2025 and 2026, 37 = 33 and 38 = 34;
- in Oct/Nov 2025, 37 = 35 and 38 = 36.
- The option codes show how they combine:
- From 2022–24 the first letter is the practical slot (A = 33-type, H = 34-type) and the second letter the written variant (X = 1, Y = 2, Z = 3). Variant-2 A Level candidates are AY (12, 22, 33, 42, 52) or HY (…34…).
- 2025 adds a second letter C = variant 4: AC (14, 24, 37, 44, 54) and HC (14, 24, 38, 44, 54), plus AS options S7 (14, 24, 37) and S8 (14, 24, 38).
- The 2026 threshold sheet lists combinations only, with no letter codes.
- Inference: variant 4 is a new administrative or time-zone variant with its own written papers, whose candidates sit an existing practical under a new code. The local files never name the zones, so this cannot be confirmed.
- Its thresholds run higher than variant 2 (A Level A):
- 2025-MJ: 177 vs 174;
- 2025-ON: 179 vs 174;
- 2026-MJ: 184 vs 168.
- Mixed options also appear in 2025-MJ: AW (12, 22, 33, 41, 52) and HW.
2. Topic weights per component (marks; variant 2)
2a. Paper 1 (MCQ, 40 marks × 9 = 360)
| Topic | 22MJ | 22ON | 23MJ | 23ON | 24MJ | 24ON | 25MJ | 25ON | 26MJ | Total | % | Sessions |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Periodicity (Period 3) | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 4 | 3 | 28 | 7.8 | 9/9 |
| Chemical bonding | 2 | 2 | 2 | 3 | 3 | 4 | 2 | 3 | 3 | 24 | 6.7 | 9/9 |
| Organic introduction & isomerism | 2 | 3 | 3 | 3 | 5 | 3 | 2 | 1 | 2 | 24 | 6.7 | 9/9 |
| Carbonyl compounds | 2 | 2 | 4 | 3 | 1 | 2 | 2 | 2 | 3 | 21 | 5.8 | 9/9 |
| Chemical energetics | 2 | 3 | 2 | 1 | 2 | 2 | 3 | 3 | 2 | 20 | 5.6 | 9/9 |
| Atomic structure | 2 | 2 | 3 | 2 | 2 | 2 | 2 | 2 | 2 | 19 | 5.3 | 9/9 |
| Group 2 | 2 | 2 | 2 | 3 | 2 | 2 | 2 | 2 | 2 | 19 | 5.3 | 9/9 |
| Carboxylic acids & derivatives | 3 | 1 | 2 | 3 | 2 | 2 | 2 | 2 | 2 | 19 | 5.3 | 9/9 |
| Equilibria | 2 | 1 | 2 | 3 | 2 | 2 | 2 | 2 | 2 | 18 | 5.0 | 9/9 |
| Atoms, molecules & stoichiometry | 2 | 2 | 2 | 3 | 2 | 1 | 2 | 1 | 2 | 17 | 4.7 | 9/9 |
| Electrochemistry & redox | 2 | 2 | 2 | 2 | 2 | 2 | 1 | 2 | 2 | 17 | 4.7 | 9/9 |
| Nitrogen & sulfur | 2 | 2 | 3 | – | 2 | 2 | 2 | 2 | 2 | 17 | 4.7 | 8/9 |
| Group 17 | 2 | 2 | – | 2 | 2 | 2 | 2 | 2 | 2 | 16 | 4.4 | 8/9 |
| Hydrocarbons | 2 | 1 | 3 | 2 | 2 | – | 1 | 3 | 2 | 16 | 4.4 | 8/9 |
| Hydroxy compounds | 1 | 3 | 1 | 1 | 2 | 2 | 3 | 2 | 1 | 16 | 4.4 | 9/9 |
| Reaction kinetics | 2 | 2 | 2 | 1 | 1 | 2 | 2 | 1 | 1 | 14 | 3.9 | 9/9 |
| Halogen compounds | 2 | 2 | 2 | – | 2 | 1 | 3 | 1 | 1 | 14 | 3.9 | 8/9 |
| States of matter | 2 | 2 | 1 | 3 | 1 | 1 | 1 | 1 | 1 | 13 | 3.6 | 9/9 |
| Analytical techniques | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 9 | 2.5 | 9/9 |
| Nitrogen compounds | 1 | – | – | – | – | 1 | 1 | 2 | 2 | 7 | 1.9 | 5/9 |
| Polymerisation | 1 | 1 | – | – | 1 | 1 | 1 | 1 | 1 | 7 | 1.9 | 7/9 |
| Organic synthesis | – | 1 | – | 1 | – | 2 | – | – | 1 | 5 | 1.4 | 4/9 |
- P1 is extremely evenly spread. No topic exceeds 8%, and 19 of 22 AS topics appear in at least 8 of 9 sessions.
- The split by area is stable at Physical ≈ 39%, Inorganic ≈ 22%, Organic ≈ 36%, Analysis 2.5%. Only 1–2 percentage points move between 2022–23 and 2025–26.
- Most reliable single items (subtopic present in ≥ 7 of 9 sessions):
| Subtopic | Sessions present | Marks (9 sessions) |
|---|---|---|
| Period 3 oxides & chlorides (reaction with water, pH, bonding) | 9/9 | 15 |
| Oxidation numbers & redox | 9/9 | 14 |
| Stereoisomer counting (cis/trans × chiral centres) | 9/9 | 14 |
| Ideal gas equation | 9/9 | 10 |
| Esters (formation & hydrolysis) | 8/9 | 10 |
| Alcohol oxidation | 8/9 | 9 |
| Ionisation energies | 8/9 | 8 |
| Kc/Kp calculations | 8/9 | 8 |
| Carbonyl tests | 7/9 | 9 |
| VSEPR shapes & bond angles | 7/9 | 8 |
| NH3/NH4+ | 7/9 | 8 |
| Le Chatelier | 7/9 | 7 |
| Group 2 thermal decomposition | 7/9 | 7 |
| Group 2 solubility | 7/9 | 7 |
| Addition polymers | 7/9 | 7 |
2b. Paper 2 (AS structured, 60 marks × 9 = 540)
| Topic | 22MJ | 22ON | 23MJ | 23ON | 24MJ | 24ON | 25MJ | 25ON | 26MJ | Total | % | Sessions |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chemical bonding | 4 | 12 | 13 | 8 | 5 | 10 | 9 | 5 | 2 | 68 | 12.6 | 9/9 |
| Periodicity (Period 3) | – | 7 | 9 | 3 | 12 | 6 | 8 | 8 | 4 | 57 | 10.6 | 8/9 |
| Hydrocarbons | – | 1 | 6 | 4 | – | 5 | 8 | 10 | 9 | 43 | 8.0 | 7/9 |
| Atomic structure | 1 | 3 | – | 7 | 3 | 8 | 6 | 6 | 8 | 42 | 7.8 | 8/9 |
| Equilibria | 7 | 2 | 2 | 8 | 9 | – | – | 6 | 4 | 38 | 7.0 | 7/9 |
| Organic introduction & isomerism | 5 | 3 | 2 | 3 | 5 | 1 | 1 | 7 | 7 | 34 | 6.3 | 9/9 |
| Organic synthesis | 3 | 12 | 2 | 4 | 4 | 4 | – | – | 4 | 33 | 6.1 | 7/9 |
| Halogen compounds | 10 | 5 | 1 | 1 | 5 | 3 | 2 | 1 | 1 | 29 | 5.4 | 9/9 |
| Chemical energetics | 7 | – | 2 | 4 | 8 | 1 | 2 | 2 | – | 26 | 4.8 | 7/9 |
| Analytical techniques | 3 | 3 | 2 | 5 | 4 | – | 1 | 4 | 4 | 26 | 4.8 | 8/9 |
| Atoms, molecules & stoichiometry | 1 | 3 | 3 | – | – | 4 | 8 | – | 2 | 21 | 3.9 | 6/9 |
| Group 17 | 6 | 2 | 3 | – | – | – | – | – | 6 | 17 | 3.1 | 4/9 |
| Hydroxy compounds | – | – | 1 | 1 | 3 | 2 | 5 | 2 | 3 | 17 | 3.1 | 7/9 |
| Group 2 | 6 | – | – | 2 | 2 | 1 | – | 4 | 1 | 16 | 3.0 | 6/9 |
| Electrochemistry & redox | 2 | – | 1 | 2 | – | 2 | – | 4 | 2 | 13 | 2.4 | 6/9 |
| Nitrogen & sulfur | – | 1 | – | 5 | – | 7 | – | – | – | 13 | 2.4 | 3/9 |
| Carboxylic acids & derivatives | 2 | – | 5 | 2 | – | – | 2 | 1 | – | 12 | 2.2 | 5/9 |
| Reaction kinetics | – | – | 3 | 1 | – | – | 5 | – | 3 | 12 | 2.2 | 4/9 |
| Nitrogen compounds | 1 | – | 2 | – | – | 1 | 3 | – | – | 7 | 1.3 | 4/9 |
| Carbonyl compounds | – | – | 3 | – | – | 4 | – | – | – | 7 | 1.3 | 2/9 |
| Polymerisation | 2 | 3 | – | – | – | 1 | – | – | – | 6 | 1.1 | 3/9 |
| States of matter | – | 3 | – | – | – | – | – | – | – | 3 | 0.6 | 1/9 |
- Area split: Physical 41%, Organic 35%, Inorganic 19%, Analysis 5%.
- Bonding + Period 3 + atomic structure = 31% of all P2 marks.
- The typical P2 has three kinds of question:
- one "Period 3 / bonding / atomic structure" question (oxides and chlorides with water, melting points, dot-and-cross, electronic configuration, isotopes and Ar);
- one physical question (Kp/Kc and Le Chatelier, or a Hess/calorimetry calculation);
- one or two organic questions ending in IR or mass-spectrum deduction.
- The analysis marks are effectively 9/9. In 2024-ON the spectra sit inside a "deduce the structure" part, which was tagged Organic synthesis.
- Halogenoalkanes appear in every session, usually as reagents and conditions plus an SN1/SN2 mechanism (2022-MJ, 2022-ON, 2024-MJ).
2c. Paper 4 (A Level structured, 100 marks × 9 = 900)
| Topic | 22MJ | 22ON | 23MJ | 23ON | 24MJ | 24ON | 25MJ | 25ON | 26MJ | Total | % | Sessions |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Transition element complexes | 16 | 18 | 11 | 17 | 12 | 12 | 8 | 13 | 12 | 119 | 13.2 | 9/9 |
| Nitrogen compounds | 15 | 9 | 5 | 14 | 22 | 3 | 16 | 8 | 16 | 108 | 12.0 | 9/9 |
| Equilibria | 11 | 9 | 2 | 12 | 10 | 15 | 11 | 12 | 10 | 92 | 10.2 | 9/9 |
| Electrochemistry & redox | 8 | 11 | 9 | 14 | 6 | 3 | 4 | 8 | 11 | 74 | 8.2 | 9/9 |
| Reaction kinetics | – | 10 | 9 | 9 | 9 | 11 | 10 | 6 | 10 | 74 | 8.2 | 8/9 |
| Hydrocarbons (arenes) | 10 | 8 | 11 | 6 | 2 | 10 | 4 | 10 | – | 61 | 6.8 | 8/9 |
| Analytical techniques | 5 | 12 | 6 | 10 | 6 | 4 | 6 | 6 | 6 | 61 | 6.8 | 9/9 |
| Chem. energetics (A Level: lattice, Born–Haber, hydration) | 9 | 8 | 10 | – | 9 | 9 | – | 6 | – | 51 | 5.7 | 6/9 |
| Group 2 | 6 | 2 | 6 | 3 | 7 | 3 | 4 | 7 | 6 | 44 | 4.9 | 9/9 |
| Carboxylic acids & derivatives | 6 | 6 | 4 | 3 | 4 | 7 | 4 | 6 | 4 | 44 | 4.9 | 9/9 |
| Transition elements | 2 | 4 | 5 | 4 | 5 | 6 | 5 | 1 | 3 | 35 | 3.9 | 9/9 |
| Entropy & Gibbs free energy | 4 | 3 | 2 | 4 | 5 | 5 | 8 | – | – | 31 | 3.4 | 7/9 |
| Organic introduction & isomerism | 2 | – | 5 | – | 1 | 5 | 3 | 6 | 2 | 24 | 2.7 | 7/9 |
| Polymerisation | 5 | – | – | 4 | 2 | 3 | 4 | 3 | 3 | 24 | 2.7 | 7/9 |
| Organic synthesis | – | – | 7 | – | – | – | 3 | 2 | 10 | 22 | 2.4 | 4/9 |
| Hydroxy compounds (phenol) | – | – | 5 | – | – | – | 5 | – | 2 | 12 | 1.3 | 3/9 |
| Atoms, molecules & stoichiometry | – | – | – | – | – | – | 4 | – | 5 | 9 | 1.0 | 2/9 |
| Carbonyl compounds | 1 | – | – | – | – | – | – | 5 | – | 6 | 0.7 | 2/9 |
| Halogen compounds (halogenoarenes) | – | – | 2 | – | – | 3 | – | – | – | 5 | 0.6 | 2/9 |
| Chemical bonding | – | – | 1 | – | – | 1 | – | 1 | – | 3 | 0.3 | 3/9 |
| Group 17 | – | – | – | – | – | – | 1 | – | – | 1 | 0.1 | 1/9 |
- Area split: Physical 37%, Organic 34%, Inorganic 22%, Analysis 7%.
- Transition elements + complexes together = 17% (154 marks). They are present every session, usually as one complete question of 10–20 marks.
- Combined A Level energetics (lattice/Born–Haber + entropy/Gibbs) is in 8 of 9 sessions, 4–14 marks each. 2026-MJ has none at all, the first gap.
- Nitrogen compounds are the biggest organic block (12%): basicity order with explanation, azo-dye synthesis, acyl chloride + amine mechanisms, amino acids and peptides.
- A typical P4 has nine questions:
- one Group 2 / lattice-energy question;
- one transition-metal question;
- one kinetics question;
- one acid–base / buffer / Ksp question;
- one electrochemistry question;
- two or three arene / phenol / nitrogen-compound questions;
- one NMR question;
- one polymer or synthesis question.
2d. Paper 5 (30 marks × 9 = 270)
| Topic | 22MJ | 22ON | 23MJ | 23ON | 24MJ | 24ON | 25MJ | 25ON | 26MJ | Total | % |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Practical skills | 25 | 23 | 19 | 21 | 23 | 24 | 26 | 22 | 23 | 206 | 76.3 |
| Atoms, molecules & stoichiometry | 3 | 5 | 6 | 2 | 1 | 6 | 1 | 4 | 5 | 33 | 12.2 |
| Equilibria | – | – | 4 | – | 3 | – | – | 4 | – | 11 | 4.1 |
| Chemical energetics | – | – | – | 4 | 3 | – | 3 | – | – | 10 | 3.7 |
| Reaction kinetics | 2 | – | – | 3 | – | – | – | – | 2 | 7 | 2.6 |
| States of matter / Carboxylic acids | – | 2 | 1 | – | – | – | – | – | – | 3 | 1.1 |
Practical-skill marks by type (9 sessions):
| Skill | Marks |
|---|---|
| Planning: method & apparatus | 45 |
| Evaluation: errors, reliability & improvements | 30 |
| Making a standard solution / dilution | 25 |
| Data processing (tables, significant figures) | 25 |
| Graph plotting & line of best fit | 21 |
| Gradient/tangent and derived value | 17 |
| Anomalous point | 12 |
| Variables | 10 |
| Percentage error | 8 |
| Safety | 5 |
| Organic preparation techniques | 6 |
Chemistry marks come mainly from mole/titration calculations (26 marks), then calorimetry, K and rate deductions.
2e. Paper 3 (variant 33; 40 marks × 3 = 120)
| Topic / skill | 2023-MJ | 2025-MJ | 2026-MJ | Total |
|---|---|---|---|---|
| Qualitative analysis (cations, anions, gases) | 15 | 16 | 11 | 42 |
| Titration: results table, accuracy, mean titre | 8 | 8 | 8 | 24 |
| Titration calculations (redox or acid–base, incl. deducing the equation) | 5 | 3 | 3 | 11 |
| Second experiment (rates / thermochemistry / gas collection), recording & processing | 6 | 5 | 3 | 14 |
| Chemistry from the second experiment (rate order, ΔH, gas-volume moles, ionic equation) | 2 | 3 | 3 | 8 |
| Evaluation, % error, significant figures | 4 | 5 | 5 | 14 |
| Organic qualitative tests (halide after hydrolysis, C=C test) | – | – | 5 | 5 |
| Other (Mr and identity of a group from titre + test) | – | – | 2 | 2 |
| Total | 40 | 40 | 40 | 120 |
3. Bankers (examined in every session, or nearly every session)
AS (P1 + P2)
- Period 3 oxides and chlorides.
- In every P1 (1–2 items) and 8/9 P2s (41 marks).
- The usual task: write the equation with water (SiCl4, PCl5, P4O10, Na2O, Al2O3/amphoteric), give the pH, and state the bonding and structure.
- The best-tested AS item overall.
- Chemical bonding.
- 9/9 in both papers; 12.6% of P2.
- What comes up: metallic bonding diagrams; melting points explained by structure; dot-and-cross (including dative bonds, e.g. Al2Cl6 and SCN–); hydrogen-bond diagrams with lone pairs and δ charges; σ/π overlap and hybridisation; VSEPR angles.
- Atomic structure.
- Every P1 (2 items) and 8/9 P2s.
- What comes up: particle counts in ions; electrons-in-boxes and full configurations (4s lost before 3d); successive and first IE explanations; orbital shapes; atomic/ionic radius.
- Isomerism.
- Every P1 (counting stereoisomers is a near-certain MCQ) and every P2.
- What comes up: structural isomer names, cis/trans condition, chiral centre.
- Redox and oxidation numbers.
- Every P1 (≈ 2 items: change of oxidation state, identify the oxidising/reducing agent, disproportionation).
- 6/9 P2s: balancing from half-equations, Cl2 + NaOH.
- Equilibria.
- Kp/Kc or Le Chatelier in every P1 and 7/9 P2s.
- P2 often asks for a Kp expression with partial pressures plus a moles calculation.
- Energetics.
- Every P1 (Hess cycle, bond energies, calorimetry, definitions).
- 7/9 P2s (definition of ΔHf; q = mcΔT → kJ mol⁻¹ with sign; Hess using a given value).
- Halogenoalkanes.
- Every P2 and 8/9 P1s.
- What comes up: reagent and conditions table (aq OH⁻ vs ethanolic OH⁻, KCN in ethanol, NH3 in ethanol), SN1 vs SN2 with mechanism, C–X bond strength and rate.
- Alkenes and alcohols.
- Electrophilic addition mechanism (HBr/Br2/steam) with Markovnikov explanation.
- KMnO4 cold/hot.
- Alcohol oxidation with K2Cr2O7 (orange → green; reflux vs distil).
- Analysis at AS: - P1 Q40 every session (MS 6×, IR 3×); - P2 mass spectrum (M+, M+1 → number of carbons, fragments with + charge) and IR (which bond, which range) in every session.
- Group 2 and nitrogen at AS. - Group 2 is in every P1 (hydroxide/sulfate solubility trend, carbonate/nitrate decomposition). - Nitrogen & sulfur is in 8 of 9 P1s (NH4+ test, NOx and catalytic converters, SO2 and acid rain).
- Stoichiometry. - ≈ 2 MCQs per session (empirical formula from combustion data, gas volumes, ideal gas equation). - A titration or Ar calculation in 6/9 P2s.
A Level (P4)
| Subtopic | Sessions | Marks (9 sessions) | Typical demand |
|---|---|---|---|
| Ligand exchange & stability constants | 9/9 | 53 | Co²⁺/Cu²⁺ with NH3, Cl⁻, OH⁻: formulae, colours, Kstab expression (charge inside the brackets) |
| Proton NMR | 9/9 | 47 | splitting, number of H, D2O/TMS/CDCl3, structure from spectrum |
| Group 2 solubility & thermal stability (explained) | 9/9 | 43 | ionic radius → polarisation of anion; ΔHlatt vs ΔHhyd for sulfates/hydroxides |
| Complex ions: ligands, shape, coordination number | 9/9 | 27 | define complex/bidentate ligand, 3-D diagrams |
| Arenes: electrophilic substitution | 8/9 | 51 | nitration / Friedel–Crafts / halogenation mechanism and directing effects |
| Standard electrode potentials & cells | 8/9 | 39 | cell diagram, E°cell, feasibility, electron flow |
| Rate equations & orders | 8/9 | 37 | initial-rates table → orders, rate equation, k with units |
| Phenylamine & azo dyes | 8/9 | 33 | Sn/HCl reduction, HNO2 below 10 °C, coupling in alkali |
| Ksp & common-ion effect | 8/9 | 31 | Ksp from solubility or pH; units; common-ion prediction |
| Isomerism in complexes | 8/9 | 24 | cis/trans and optical isomers of octahedral complexes |
| Buffers | 7/9 | 31 | definition, two equations, pH from Ka and ratio |
| Amides | 7/9 | 28 | acyl chloride + amine mechanism, amide hydrolysis, weak basicity |
| Gibbs free energy & feasibility | 7/9 | 27 | ΔG = ΔH – TΔS, temperature for feasibility, units (÷1000) |
| Condensation polymers | 7/9 | 20 | polyester/polyamide repeat units from monomers and back |
| Relative acidity | 7/9 | 19 | ethanol < water < phenol < carboxylic acid < chloro-acid, with reasons |
| Colour & d-orbital splitting | 7/9 | 15 | degenerate/non-degenerate, ΔE, complementary colour, why Ag⁺/Cu⁺/Zn²⁺ are colourless |
| Amino acids, peptides, electrophoresis | 6/9 | 25 | zwitterion/ionic forms vs pH, isoelectric point, dipeptide drawing |
| Redox titrations (MnO4⁻, Cr2O7²⁻) | 6/9 | 23 | multi-step titration with ratio 1:5 or 2:5 |
| Lattice energy & Born–Haber | 5/9 | 27 | definitions, cycle with 2× factors, trend with ionic radius/charge |
P5
- Two questions every session. Q1 is usually quantitative (titration, gas or calorimetry), with a plan-style opening.
- Making up a standard solution (from a solid, or by dilution) is in 8 of 9 sessions, ≈ 3 marks each. It is the closest thing to a guaranteed P5 mark.
- A graph task is in every session:
- plot with a line of best fit;
- circle and explain the anomaly;
- gradient from two line points, to 3 s.f.;
- use the gradient to get Ea, ΔH, an order or a constant (in 7 of 9).
- Percentage error (single vs double reading) is in 7 of 9 sessions.
P3
- Q3 is always qualitative analysis, in all 18 Paper 33/34 papers 2022–2026.
- A titration is in at least one question of 13 of 18 papers (12 titration experiments, plus a rate followed by quenching titration in 34/2024-ON).
- A results table with burette readings to 0.05 cm³ (≈ 7–8 marks) is effectively certain when there is a titration.
4. Rarely tested, and trends
Rarely tested in this sample (variant 2)
- P2:
- States of matter: 3 marks in nine papers (the ideal gas equation lives in P1).
- Carbonyl compounds: 2 sessions.
- Polymerisation and nitrogen & sulfur: 3 sessions each.
- Kinetics, Group 17 and AS nitrogen compounds (amines, nitriles): 4 sessions each.
- Carboxylic acids: 5 sessions.
- P4:
- Partition coefficient: 2026 only.
- Chromatography (TLC Rf, GC retention): 2022-ON and 2023-ON only.
- Halogenoarenes vs halogenoalkanes: 2023-MJ and 2024-ON.
- Enthalpies of solution & hydration: 2022-ON and 2024-ON.
- Electron affinity: 3 sessions.
- Nernst equation: 4 sessions, 8 marks.
- ΔG–E°cell link: 3 sessions.
- Phenol chemistry: 3 sessions.
- Carbonyl chemistry at A Level: 2 sessions.
- Never seen in variant-2 P4: an Arrhenius-type calculation (it appears in P5 2022-MJ instead), a halogenoarene mechanism, and an addition polymer as a main question.
- P1:
- Organic synthesis: 4 of 9 sessions.
- Nitrogen compounds (nitriles/amines): 5 of 9 sessions.
Trends from 2022 to 2026
Earlier (2022–23, 4 sessions) vs later (2025–26, 3 sessions), share of each paper's marks:
| Change | P1 | P2 | P4 |
|---|---|---|---|
| Atomic structure | 5.6 → 5.0% | 4.6 → 11.1% | – |
| Chemical bonding | 5.6 → 6.7% | 15.4 → 8.9% | – |
| Hydrocarbons | 5.0 → 5.0% | 4.6 → 15.0% (free-radical substitution of alkanes, 12 marks in 2025-ON + 2026-MJ) | 8.8 → 4.7% (arenes absent in 2026-MJ) |
| Organic synthesis | 1.2 → 0.8% | 8.8 → 2.2% | 1.8 → 5.0% |
| Halogen compounds | 3.8 → 4.2% | 7.1 → 2.2% | – |
| Nitrogen compounds | 0.6 → 4.2% | 1.2 → 1.7% | 10.8 → 13.3% |
| Transition complexes | – | – | 15.5 → 11.0% |
| Lattice / Born–Haber | – | – | 6.8 → 2.0% (none in 2025-MJ or 2026-MJ) |
| Equilibria | 5.0 → 5.0% | 7.9 → 5.6% | 8.5 → 11.0% |
| Kinetics | 4.4 → 3.3% | 1.7 → 4.4% | 7.0 → 8.7% |
Other observations:
- Area balance is stable. Physical/Inorganic/Organic stays near 40/20/35 in every paper.
- Fewer, longer questions in P2. The count swings between 3 and 6, and from 2023 alternates 5 (May/June) and 4 (Oct/Nov), until 6 in 2026-MJ.
- More numerical work at A Level. Titration-style stoichiometry entered P4 in 2025-MJ (Sr(OH)2 titration) and 2026-MJ (ethanedioate mixture, 5 marks).
- Both 2026 papers lean on synthesis: P4 2026 has two "fill in the route" questions (10 marks).
- Grade thresholds have risen steadily (§8). The P4 A threshold went from 61 (2022-MJ) to 63–69 (2025–26), and the A Level A from 153 to 168–174. Papers did not obviously get easier, so this most likely reflects the return to pre-pandemic grading standards.
- 2026 format changes: "Figure", ⦵ and "London dispersion forces" (§1a).
5. Practical papers: experiment types
P5 contexts (variant 2)
| Session | Question 1 | Question 2 |
|---|---|---|
| 2022-MJ | molar gas volume from Mg + HCl (gas collection over water) | rate of KI-catalysed H2O2 decomposition vs temperature → log rate vs 1/T → Ea |
| 2022-ON | % CaCO3 in eggshell by back titration | diffusion rate of KMnO4 through a gel (tangent gradient; K2Cr2O7 comparison) |
| 2023-MJ | preparation of benzoic acid by hydrolysis of methyl benzoate (reflux, filtration, % yield, limiting reagent) | Kw vs temperature → log Kw vs 1/T → ΔH of water dissociation |
| 2023-ON | thermometric titration HCl/NaOH → concentration and ΔHneut | Zn + HCl rate vs concentration (1/t graph, order, surface area) |
| 2024-MJ | indirect ΔH for CaCO3 decomposition (calorimetry with extrapolation + Hess) | Fe³⁺/SCN⁻ equilibrium by colorimetry at different T → ΔH |
| 2024-ON | Na2CO3 standard solution, titration and evaporation to NaCl | mass of sulfur reacting with metal M → gradient → formula of sulfide |
| 2025-MJ | adsorption of ethanedioic acid on activated carbon (dilution, titration, curved graph, q0) | ΔHc of butane by calorimetry, heat loss, % error |
| 2025-ON | Kc for Ag⁺ + Fe²⁺ ⇌ Ag + Fe³⁺ (Volhard-type titration with KSCN) | conductometric titration of sulfate with Ba(OH)2, plus a gravimetric alternative |
| 2026-MJ | formula of a polyiodide (CH3)4NI(2n+1) (standard solution, crystallisation, titration) | order of a persulfate reaction from a log–log graph; error vs gradient |
- Titration in some form: 6 of 9 sessions.
- A log/1/T graph giving Ea or ΔH: 3 of 9 sessions.
- Calorimetry: 3 of 9 sessions.
P3 variant 33 (tagged)
- 2023-MJ:
- Q1: redox titration, KMnO4 vs Fe²⁺ formed from hydroxylamine; deduce the reacting ratio.
- Q2: thiosulfate/acid rate at several concentrations; order from data, % error, improvements.
- Q3: qualitative analysis of a solid mixture of two salts and an N-containing ion.
- 2025-MJ:
- Q1: KMnO4/H2O2 titration.
- Q2: the same H2O2 concentration found thermochemically (temperature rise, energy change, comparison of methods).
- Q3: MnO2 as oxidant and catalyst; identification of ions in two solutions.
- 2026-MJ:
- Q1: H2 volume from Mg + a carboxylic acid (gas collection, moles, ionic equation, % error).
- Q2: NaOH titration of a substituted carboxylic acid → Mr; halide test after hydrolysis → identity of the substituent.
- Q3: C=C test on the acid, then cations/anions in two solutions.
All 36 quantitative experiments in Papers 33 and 34, 2022–2026
Classified from the method text; Q3 is qualitative analysis in all 18 papers.
| Experiment type | Count | Where |
|---|---|---|
| Titration (acid–base, KMnO4 redox, iodine/thiosulfate) | 12 | 33: 22MJ, 22ON, 23MJ, 23ON, 24MJ, 24ON (Q2), 25MJ, 26MJ (Q2); 34: 24MJ, 25MJ, 25ON (Q2), 26MJ |
| Thermochemistry (ΔH neutralisation, solution, Hess pair, thermometric titration) | 10 | 33: 23ON, 24MJ, 25MJ, 25ON; 34: 22MJ, 22ON, 23MJ, 23ON, 25MJ, 25ON |
| Gravimetric / thermal decomposition (MCO3, hydrated salts, basic carbonates) | 7 | 33: 22MJ, 22ON; 34: 22ON, 23MJ, 24MJ, 24ON, 26MJ |
| Rates (thiosulfate–acid, Fe³⁺ + I⁻, iodine–propanone with quenching) | 4 | 33: 23MJ, 25ON; 34: 23ON, 24ON |
| Gas evolution / mass loss (carbonate + acid, Mg + acid) | 3 | 33: 24ON, 26MJ; 34: 22MJ |
- Organic tests appear in Q3 in several papers (hot-water-bath tests for C=C, alcohols, carbonyls, halides), e.g. 34/2022-MJ, 34/2023-MJ, 33/2025-ON, 33/2026-MJ.
6. Question styles (P2, P4 and P5, by command word)
Keyword-based on the command phrase of each part. Each part is counted once, by its first matching style in the order shown.
| Style | P2 marks (%) | P4 marks (%) | P5 marks (%) |
|---|---|---|---|
| Explain / suggest / compare / predict | 130 (24%) | 189 (21%) | 77 (29%) |
| State / name / identify (short recall) | 118 (22%) | 127 (14%) | 78 (29%) |
| Calculation | 49 (9%)* | 152 (17%) | 88 (33%) |
| Equations | 64 (12%) | 78 (9%) | 4 (1%) |
| Reagents, conditions, synthesis routes | 56 (10%) | 89 (10%) | 1 |
| Drawing structures / 3-D diagrams / repeat units | 50 (9%) | 115 (13%) | 22 (8%, graphs) |
| Definitions ("define", "what is meant by") | 25 (5%) | 52 (6%) | – |
| Mechanisms with curly arrows | 25 (5%) | 50 (6%) | – |
| Spectra / chromatography interpretation | 23 (4%) | 48 (5%) | – |
*Many P2 calculations sit inside "Use the data…" or "Deduce…" parts and are counted under other styles. By hand the P2 calculation share is nearer 15–20% (Kp, Hess, titration, Ar, ideal gas, ΔH from q).
Mechanisms are examined in every P2 and every P4:
- P2:
- electrophilic addition: 4 times (steam/H3PO4, Br2, HBr);
- SN1/SN2: 3 times;
- free-radical substitution written as propagation equations: 2 times (2025-ON, 2026-MJ).
- P4:
- electrophilic substitution on an arene: 6 of 9 (nitration, Friedel–Crafts methylation, chlorination, SOBr2 bromination);
- nucleophilic addition–elimination of an acyl chloride with an amine/NH3: 3 of 9;
- curly arrows on the carbonate ion decomposing: 2023-MJ and 2026-MJ;
- radical or two-step mechanisms in kinetics: 2024-MJ, 2025-MJ and 2026-MJ.
Recurring formats:
- "Complete the table" of reagents and observations (2,4-DNPH, Tollens', Fehling's, alkaline I2, Br2, Na, Na2CO3) is in most P2s and many P4s.
- So is a three-step "fill in the route" synthesis.
- P4 almost always includes one 3-D diagram (complex isomers or optical isomers) and one condensation-polymer repeat unit.
7. Common mistakes (examiner reports for 2022-MJ, 2022-ON, 2023-MJ and 2024-MJ; variants 12, 22, 42, 52, 33)
Paraphrased from the reports.
Paper 1 (MCQ)
- Counting stereoisomers:
- candidates added (2 + 2 + 2) instead of multiplying (2 × 2 × 2) the cis/trans and chiral possibilities (2022-MJ Q26);
- they missed optical isomers formed by elimination (Q28);
- they missed positional isomers among the chloroethanes (2023-MJ Q28, nine products).
- Ideal-gas behaviour: candidates forgot that hydrogen bonding (steam) makes a gas least ideal (2022-MJ Q7). Only 27% knew that p ∝ 1/V (2022-ON Q15).
- Reading the question:
- giving the identity of the product instead of the starting alcohol from an IR spectrum (2024-MJ Q40);
- missing that NH3(aq) contains water that hydrolyses SiCl4 (2022-MJ Q17).
- Bond energies: candidates did not derive C–H from the atomisation of CH4 before using it (2022-ON Q16, 23% correct).
- VSEPR: the lone pair in O3 makes the angle ≈ 117°, not 120° (2022-ON Q13).
- Organic recall:
- excess HBr also substitutes –OH (2022-ON Q29);
- methyl ketones give the tri-iodomethane test but not Fehling's (2022-ON Q35);
- Cl⁺ and O are radicals because they have unpaired electrons (2024-MJ Q4);
- NH4⁺ is a weak acid (2023-MJ Q23).
- Periodicity: the formulae of Period 3 oxides are less well known than the chlorides (2023-MJ Q18).
Paper 2 (AS structured)
- Definitions lose marks on precision:
- ΔHf without "elements in their standard states" ("standard conditions" is not the same thing);
- Brønsted–Lowry acid as "releases" rather than "donates" protons;
- covalent bond without "two nuclei attracted to a shared pair";
- dynamic equilibrium without "rates equal" plus "concentrations constant" (some think concentrations become equal);
- tertiary halogenoalkane described vaguely.
- Calculations:
- working per mole of the wrong species (per mol Mg instead of per mol Mg3N2; 2 mol HI instead of 1 mol);
- no negative sign on an exothermic ΔH;
- Ar 24 instead of 24.3;
- J instead of kJ;
- early rounding of intermediate values;
- forgetting a dilution factor in a titration back-calculation;
- confusing "amount" with "concentration";
- confusing 2x with x².
- Structure and bonding:
- covalent dot-and-cross drawn for an ionic compound;
- intermolecular forces confused with covalent bonds (e.g. "giant molecular with intermolecular forces" for silicon);
- "van der Waals" used ambiguously;
- two hydrogen bonds drawn between a pair of NH3 molecules;
- no lone pair or δ charges on hydrogen-bond diagrams.
- Inorganic equations:
- NaCl "reacting" with water to give HCl and NaOH;
- PCl5 + water giving phosphorus oxide instead of H3PO4;
- Cl2 + hot NaOH unbalanced;
- Cl written for Cl2;
- halogen and halide confused;
- claiming a reaction between Cl⁻ and Br2.
- Mechanisms:
- arrows that do not start at a lone pair or bond, or that point the wrong way;
- no lone pair on CN⁻ or OH⁻;
- SN1 and SN2 features mixed;
- homolytic and heterolytic confused.
- Organic recall:
- "reflux" misunderstood;
- NaBH4 given where LiAlH4 is needed (to reduce an acid);
- KCN and HCN conditions confused (hydroxynitrile vs nitrile);
- "no movement" instead of "no rotation" about C=C;
- missing the "e" in propanenitrile.
- Spectra:
- fragment ions written without a + charge;
- listing every possible IR bond rather than using the data given;
- quoting C–H absorptions that do not distinguish the compounds.
- Observations must be observable: e.g. "bubbles form faster". Vague phrases like "more vigorous" score nothing.
Paper 4 (A Level structured)
- Definitions:
- lattice energy without "1 mole of ionic compound formed from gaseous ions";
- first electron affinity confused with ionisation energy;
- Kstab not described as an equilibrium constant;
- conjugate acid–base pair defined as just "an acid and a base";
- standard cell potential confused with standard electrode potential;
- buffer without "small amounts of acid or base".
- Energy cycles:
- missing ×2 or ÷2 factors (2 × electron affinity of Cl, ½ bond energy);
- using the wrong data value;
- sign errors.
- ΔG:
- forgetting to divide ΔS by 1000;
- using T = 25 instead of 298;
- ΔS from a ΔG–T graph not converted to J K⁻¹ mol⁻¹.
- Group 2 / thermal stability: the polarisation of the anion by a smaller cation must be stated. Some wrote "polarisation of the cation" or answered about the wrong compound class.
- Transition metals:
- charges written outside the brackets in Kstab expressions;
- wrong complex formulae (e.g. [CoCl4]⁻);
- 3-D diagrams that cannot be octahedral or tetrahedral;
- "energy gap" without "between split d-orbitals";
- not knowing why Ag⁺ (full d-subshell) is colourless.
- Acids and buffers:
- Henderson–Hasselbalch used with the ratio inverted, or where a simple Ka calculation is needed;
- missing that [HA] = [A⁻] gives pH = pKa;
- not converting moles to concentration.
- Kinetics:
- units of k with the wrong time unit (min vs s);
- "constant half-life" claimed for a second-order reaction;
- radical species written without the dot;
- heterogeneous catalysis described with vague words ("the gas") rather than naming the species that adsorb and desorb.
- Electrochemistry:
- "cell" used for "electrode";
- no Pt electrode or H⁺ in a half-cell diagram;
- Mg⁺ used instead of Mg²⁺ in Faraday calculations;
- not saying which potential (E or Ecell) changes on dilution.
- Organic mechanisms (most-cited weaknesses):
- In electrophilic substitution: the arrow must start inside the ring; the intermediate's partial ring must exclude the sp³ carbon; the C–H bond (not the H) breaks; H⁺ must be shown at the end.
- In addition–elimination of acyl chlorides: show the N lone pair, the C=O dipole, the arrow to C=O and the C–Cl breaking.
- Organic chemistry:
- basicity explanations without "lone pair on N accepts a proton";
- acidity explanations without "weakens the O–H bond / stabilises the anion";
- diazonium written as –N≡N– in the dye;
- coupling conditions not "alkaline, below 10 °C";
- NaNO3 instead of NaNO2;
- Sn/HCl without "concentrated, heat";
- trivalent carbon in peptides, or –COO–NH– links.
- NMR:
- number of H atoms not totalling the formula;
- misnamed splitting patterns ("quartet" is required);
- imprecise use of D2O and TMS.
- Presentation: write over nothing; cross out clearly; label multi-step calculations; balance every equation for atoms and charge; write formulae with correct case (KMnO4).
Paper 5
- Percentage error:
- double the half-graduation only when two readings are taken (burette, balance, thermometer), not for a pipette or measuring cylinder;
- using the wrong measured value as the denominator.
- Standard solutions:
- dissolve in less water than the final volume;
- transfer to a volumetric flask with rinsings;
- never transfer with a pipette/burette after dissolving;
- do not choose a measuring cylinder;
- do not choose the wrong flask size.
- Weighing by difference was often not understood.
- Mean titre: use concordant titres only (within 0.10 cm³). Many averaged everything, including the rough titre.
- Graphs:
- lines forced through the first or last point (including the anomaly);
- gradients from table points rather than from the line;
- coordinates too close together;
- gradients not to 3 s.f.
- Anomalies need a direction (e.g. "measured too early"). "Measured wrongly" scores nothing. Remember continuous experiments.
- Lists: extra answers beyond those asked for are penalised if any is wrong (controlled variables, safety).
- Lab practice gaps:
- why reflux is used;
- removing anti-bumping granules;
- removing oxide from Mg ribbon (sandpaper);
- heating to constant mass.
Paper 3 (33)
- Record all burette readings, including the rough titre, to ##.#0 or ##.#5 cm³.
- Stop when two accurate titres agree within 0.10 cm³; select titres within 0.20 cm³ for the mean.
- Use the volume actually measured in % error, and do not double the error for a single reading.
- In qualitative work, use correct terms: a solid dissolving is not a precipitate. Test gases as soon as heating starts (litmus, limewater ready). Use the Qualitative Analysis Notes.
- "Improvements" must respect the stated limits, e.g. extra separate experiments rather than repeats, and no changes of apparatus when this is forbidden.
8. Grade thresholds (variant-2 options)
Component thresholds, A / E (raw)
| Session | P1 (12) /40 | P2 (22) /60 | P3 (33) /40 | P4 (42) /100 | P5 (52) /30 |
|---|---|---|---|---|---|
| 2022-MJ | 24 / 11 | 32 / 7 | 21 / 7 | 61 / 19 | 20 / 10 |
| 2022-ON | 24 / 11 | 32 / 9 | 25 / 11 | 57 / 20 | 21 / 8 |
| 2023-MJ | 27 / 11 | 36 / 9 | 22 / 10 | 60 / 18 | 21 / 10 |
| 2023-ON | 26 / 11 | 39 / 13 | 27 / 13 | 60 / 21 | 21 / 10 |
| 2024-MJ | 27 / 11 | 38 / 11 | 25 / 11 | 63 / 20 | 20 / 9 |
| 2024-ON | 25 / 11 | 40 / 18 | 23 / 10 | 67 / 22 | 24 / 11 |
| 2025-MJ | 27 / 12 | 39 / 14 | 22 / 12 | 69 / 22 | 22 / 11 |
| 2025-ON | 25 / 12 | 43 / 20 | 26 / 13 | 63 / 21 | 23 / 11 |
| 2026-MJ | 25 / 11 | 37 / 12 | 22 / 10 | 66 / 20 | 23 / 11 |
Overall thresholds (weighted marks)
| Session | A Level AY (12-22-33-42-52), /260: A* / A / B / C / D / E | AS S3 (12-22-33), /130: A / B / C / D / E |
|---|---|---|
| 2022-MJ | 184 / 153 / 122 / 98 / 75 / 52 | 72 / 56 / 45 / 34 / 23 |
| 2022-ON | 177 / 153 / 129 / 104 / 80 / 56 | 75 / 61 / 50 / 39 / 28 |
| 2023-MJ | 197 / 161 / 125 / 102 / 79 / 56 | 80 / 60 / 49 / 38 / 28 |
| 2023-ON | 190 / 166 / 142 / 116 / 90 / 65 | 85 / 69 / 57 / 45 / 34 |
| 2024-MJ | 200 / 167 / 134 / 109 / 84 / 59 | 84 / 66 / 54 / 42 / 30 |
| 2024-ON | 197 / 173 / 149 / 122 / 96 / 70 | 82 / 70 / 59 / 48 / 37 |
| 2025-MJ | 206 / 174 / 142 / 117 / 92 / 68 | 83 / 68 / 57 / 46 / 35 |
| 2025-ON | 199 / 174 / 149 / 124 / 99 / 74 | 88 / 76 / 64 / 53 / 42 |
| 2026-MJ | 201 / 168 / 135 / 110 / 86 / 62 | 79 / 62 / 51 / 41 / 31 |
Variant 4 for comparison (AC = 14-24-37-44-54; AS 14-24-37):
| Session | A Level A* / A / E | AS A / E |
|---|---|---|
| 2025-MJ | 206 / 177 / 71 | 85 / 35 |
| 2025-ON | 207 / 179 / 80 | 89 / 41 |
| 2026-MJ | 215 / 184 / 71 | 92 / 37 |
Reading the thresholds
- As a percentage of 260, the A Level A rose from 59% (2022) to 66–67% (2024-ON to 2025-ON). It was 65% in 2026-MJ. The A* sits at 76–79% from 2024-MJ on.
- The AS A rose from 55% (2022-MJ) to 61–68% (2025-ON highest at 68%).
- P2 is the paper with the lowest E threshold relative to its maximum (7–20/60). A candidate who secures the bankers in §3 is well above E.
- P4 A needs about two-thirds of the marks (61–69/100). P5 A needs 20–24/30, so P5 marks are "dear" at the top.
- Oct/Nov thresholds have been at least as high as May/June since 2023-ON.
9. Revision priorities
AS (P1 + P2), in order of marks per hour of revision
- Period 3:
- oxides and chlorides with water (equations with state symbols, pH, bonding and structure);
- melting-point trend explained by structure;
- amphoteric Al2O3/Al(OH)3 with NaOH (product formula).
- Bonding:
- metallic diagram (cations in a sea of delocalised electrons);
- dot-and-cross for ions, dative bonds (Al2Cl6, NH4⁺, SCN⁻);
- VSEPR angles (lone pair –2.5° per pair; O3 ≈ 117°);
- σ/π overlap and sp/sp²/sp³;
- hydrogen-bond diagrams (lone pair, δ+/δ–, 180°);
- id–id strength vs number of electrons.
- Atomic structure: particle counts in ions, full configurations (Fe³⁺, Cr, Cu), IE equations and anomalies (Mg/Al, P/S), radius changes on ionisation.
- Calculations drill:
- pV = nRT with unit conversion (cm³ → m³, °C → K);
- empirical formula from combustion;
- titration back-calculation with dilution factor;
- Ar from abundances;
- q = mcΔT → ΔH per mole with sign;
- Hess from ΔHf/ΔHc;
- bond energies per mole asked;
- Kp from partial pressures.
- Equilibria: Kc/Kp expressions, Le Chatelier explanations naming the forward/backward reaction and "fewer gas moles", Haber/Contact conditions.
- Redox: oxidation numbers (including S and V species), half-equations → full equations, disproportionation of Cl2 (cold and hot NaOH).
- Organic reagent and condition tables:
- halogenoalkanes: aq NaOH / ethanolic NaOH / KCN in ethanol / NH3 in ethanol;
- alcohols: K2Cr2O7 reflux vs distil, SOCl2/PCl5, H3PO4/Al2O3;
- alkenes: cold/hot KMnO4, steam, HBr;
- nitrile hydrolysis (acid and alkali);
- LiAlH4 vs NaBH4;
- test observations (2,4-DNPH orange, Tollens' silver mirror, Fehling's red, alkaline I2 yellow).
- Mechanisms: SN1/SN2, electrophilic addition with carbocation stability, and free-radical substitution as initiation/propagation/termination equations (rising in 2025–26).
- Isomerism: count stereoisomers by multiplying; name structural isomers; state the conditions for cis/trans.
- Spectra: M+1 → number of carbons; Cl/Br M+2 patterns; fragment formulae with + charge; IR ranges for O–H (alcohol vs acid), C=O, C=C.
A Level (P4)
- Transition metals (expect a 10–20 mark question):
- definitions (transition element, complex, ligand, bidentate);
- Co²⁺/Cu²⁺ ligand exchanges with NH3, conc. HCl and NaOH, with colours and formulae;
- Kstab expressions;
- 3-D cis/trans and optical isomers;
- d-splitting and colour;
- why Ag⁺/Cu⁺/Zn²⁺ are colourless;
- a MnO4⁻ or Cr2O7²⁻ titration with ratio and Mr deduction.
- Nitrogen compounds:
- basicity order (alkylamines > NH3 > phenylamine > amides) with lone-pair reasoning;
- phenylamine from nitrobenzene (Sn/conc. HCl, heat);
- diazotisation and coupling conditions;
- acyl chloride + amine mechanism;
- amide hydrolysis products;
- amino-acid ionic forms at given pH;
- electrophoresis;
- dipeptide and polyamide drawings.
- Acid–base and solubility equilibria:
- pH of a weak acid from Ka;
- buffer pH (moles after mixing, then ratio);
- two buffer equations;
- Ksp from solubility or pH (with units) and the common-ion effect;
- partition coefficient (new in 2026).
- Electrochemistry:
- labelled cell diagram (Pt, H⁺, 1 mol dm⁻³, 298 K, 101 kPa);
- E°cell and feasibility;
- Nernst for concentration changes;
- ΔG = –nFE;
- Faraday calculations (mol e⁻ per ion).
- Kinetics:
- orders from initial-rates tables with explicit pairs of experiments;
- k with units;
- half-life (first order only);
- rate-determining step consistent with the rate equation;
- heterogeneous catalysis in three named steps (adsorption, weakened bonds, desorption).
- Arenes and phenol:
- electrophile generation equations (NO2⁺, CH3⁺, Cl⁺) and the mechanism drawn to the examiners' points;
- directing effects (–CH3, –OH, –NH2 to 2,4; –COOH, –NO2 to 3);
- side-chain oxidation (KMnO4);
- phenol vs benzene bromination;
- acidity order.
- Group 2 at A Level: thermal stability by cation radius → anion polarisation; sulfate and hydroxide solubility through ΔHlatt vs ΔHhyd.
- Energetics:
- Born–Haber cycles with all ×2 factors;
- trends in lattice energy (radius, charge);
- enthalpy of solution/hydration cycles;
- ΔS sign from gas moles;
- ΔG and the temperature at which a reaction becomes feasible (ΔS ÷ 1000).
- Absent in 2026-MJ; still likely to return.
- NMR and synthesis: proton NMR tables (shift, splitting, number of H, D2O exchange); carbon-13 peak counting; three-step route questions with reagents and conditions.
- Polymers: polyester/polyamide repeat units (displayed linkage), monomers from a polymer section, degradability by hydrolysis.
Practical (P3 and P5)
- Standard solution and dilution procedure (≈ 3 marks in 8 of 9 P5s), written as numbered steps with named apparatus and capacities.
- Percentage error (single vs double reading); concordant mean titre; significant figures (3 s.f. by default; burette to 0.05 cm³).
- Graph routine:
- plot accurately;
- line of best fit that ignores the anomaly;
- circle and explain the anomaly with a direction;
- gradient from line points far apart, to 3 s.f.;
- convert to Ea/ΔH/order using the given equation.
- Titration and calorimetry calculations end to end, including back titrations and q = mcΔT with sign and per-mole scaling.
- Qualitative analysis (every P3): the cation/anion test notes, gas tests at the start of heating, correct observation vocabulary, ionic equations with state symbols, plus the organic tests (C=C, halide after hydrolysis).