IB Chemistry HL & SL Topic Prediction Guide

Ref	Theme	Topic / Subtopic	M20	M21	M22	M23	M24	M25★	HL only?	May 2026
IB CHEMISTRY — PAPER 1A MCQ TOPIC FREQUENCY \| May 2025 + Mapped Old Syllabus 2019–2024 \| SL & HL
Free preview: Structure 1 (Atomic model & bonding) · Further topics locked below · 🟢 = new · 🟡 = mapped old · AHL rows greyed in SL view
THEME A: UNITY & DIVERSITY — cells, classification, viruses, biodiversity (free preview)
A.1	Unity/Div	Cell structure — prokaryotic vs eukaryotic, organelles, ultrastructure, scale & magnification 🟡	✔	✔	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐ CERTAIN
A.2	Unity/Div	Classification & diversity — binomial nomenclature, phylogenetic trees, kingdoms, domains 🟡	✔	—	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐
A.3	Unity/Div	Viruses — structure, lytic & lysogenic cycles, HIV, COVID, virus-host interactions 🟢	—	—	—	—	—	✔★	SL&HL	⭐⭐⭐⭐ NEW
A.4	Unity/Div	Conservation of biodiversity — species richness, ecosystem services, threats, conservation strategies 🟡	✔	✔	—	✔	—	✔★	SL&HL	⭐⭐⭐⭐
A.HL	Unity/Div	Cladistics & gene pools — cladograms, shared derived characteristics, species concepts, speciation HL 🟢	—	—	—	—	—	✔★	HL	⭐⭐⭐⭐ HL NEW

Ref	Theme	Topic / Subtopic	M20	M21	M22	M23	M24	M25★	HL only?	May 2026
STRUCTURE 2: MODELS OF BONDING & STRUCTURE — covalent, metallic, giant ionic
S2.1	Bonding	Ionic structures — lattice energy, properties of ionic compounds, Born-Haber cycle (AHL)	✔	✔	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐
S2.2	Bonding	Covalent structures — allotropes of carbon, giant covalent (SiO2, diamond, graphite), properties	✔	✔	—	✔	✔	✔★	SL&HL	⭐⭐⭐⭐
S2.3	Bonding	Metallic structures — electron sea model, properties, alloys, conductivity	✔	—	✔	—	✔	✔★	SL&HL	⭐⭐⭐
S2.AHL	Bonding	Transition metals — d-block, variable oxidation states, complex ions, colour, catalytic properties AHL	—	—	—	—	—	✔★	AHL	⭐⭐⭐⭐ AHL
STRUCTURE 3: CLASSIFICATION OF MATTER — organic functional groups, polymers
S3.1	Organic	Functional groups — homologous series, alkanes/alkenes/alkynes/alcohols/aldehydes/ketones/carboxylic acids naming	✔	✔	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐ CERTAIN
S3.2	Organic	Polymers — addition polymerisation, condensation polymers, nylon, polyester, properties	✔	—	✔	✔	—	✔★	SL&HL	⭐⭐⭐⭐
REACTIVITY 1: WHAT DRIVES REACTIONS — energy, entropy, Gibbs energy
R1.1	Reactivity	Measuring energy changes — enthalpy, calorimetry, Hess's law, bond enthalpies, standard enthalpy	✔	✔	✔	✔	✔	✔★★	SL&HL	⭐⭐⭐⭐⭐ CERTAIN
R1.2	Reactivity	Energy diagrams — activation energy, reaction profiles, Maxwell-Boltzmann distribution, catalysts	✔	✔	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐
R1.AHL	Reactivity	Entropy & Gibbs energy — ΔS, ΔG = ΔH - TΔS, spontaneity, standard Gibbs energy of formation AHL	—	—	—	—	—	✔★★	AHL	⭐⭐⭐⭐⭐ AHL CERTAIN
REACTIVITY 2: HOW FAST & HOW FAR — kinetics, equilibrium, acids/bases (most tested)
R2.1	Kinetics	Rate of reaction — concentration/temperature/surface area/catalysts effects, collision theory, rate expression	✔	✔	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐
R2.2	Equilibrium	Chemical equilibrium — Le Chatelier's principle, Kc expression, effect of conditions on K, Haber/Contact process	✔	✔	✔	✔	✔	✔★★	SL&HL	⭐⭐⭐⭐⭐ CERTAIN
R2.3	Acids/Bases	Acids & bases — Brønsted-Lowry, strong/weak acids, pH, Ka, Kw, buffer solutions, titration curves	✔	✔	✔	✔	✔	✔★★	SL&HL	⭐⭐⭐⭐⭐ CERTAIN
REACTIVITY 3: ELECTRON TRANSFER — redox, electrochemistry, organic mechanisms
R3.1	Redox	Redox reactions — oxidation states, half-equations, balancing redox, electrochemical series, EMF	✔	✔	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐
R3.2	Electrochemistry	Electrochemical cells — voltaic cells, electrolysis, Faraday's laws, galvanic corrosion	✔	✔	✔	—	✔	✔★	SL&HL	⭐⭐⭐⭐
R3.3	Organic Rxns	Organic reaction mechanisms — addition, substitution, elimination; halogenoalkanes, alcohol reactions	✔	✔	✔	✔	✔	✔★	SL&HL	⭐⭐⭐⭐⭐
R3.AHL	Organic (AHL)	Advanced organic mechanisms — SN1/SN2, E1/E2, nucleophilic addition, benzene electrophilic substitution AHL	—	—	—	—	—	✔★	AHL	⭐⭐⭐⭐ AHL

Theme	Topic Area	M21	M22	M23	M24	M25★	Avg Marks	May 2026
IB CHEMISTRY — PAPER 2 EXTENDED RESPONSE TOPIC FREQUENCY \| May 2025 + Mapped 2019–2024
Extended questions require calculation + explanation \| Stoichiometry skills needed throughout \| AHL rows greyed in SL view
REACTIVITY 2 — Kinetics, Equilibrium & Acids/Bases: most marks available in Paper 2
R2.2	Equilibrium extended — Kc calculation, ICE tables, effect of conditions, Haber/Contact process evaluation	✔	✔	✔	✔	✔★★	12–18	⭐⭐⭐⭐⭐ CERTAIN
R2.3	Acids & bases extended — pH/pOH calculations, Ka, buffer calculations, titration curve interpretation, indicators	✔	✔	✔	✔	✔★★	12–18	⭐⭐⭐⭐⭐ CERTAIN
R2.1	Kinetics extended — rate laws, order of reaction from data, Arrhenius equation, mechanism & rate-determining step	✔	✔	✔	✔	✔★	10–14	⭐⭐⭐⭐⭐
REACTIVITY 1 — Energy & thermochemistry
R1.1	Enthalpy calculations — Hess's law multi-step, bond enthalpy calculations, calorimetry data processing	✔	✔	✔	✔	✔★★	10–14	⭐⭐⭐⭐⭐ CERTAIN
R1.AHL	Entropy & Gibbs — ΔG calculations, spontaneity conditions, ΔG° from standard values, Born-Haber AHL	—	—	—	—	✔★★	12–16	⭐⭐⭐⭐⭐ AHL CERTAIN
REACTIVITY 3 — Redox, electrochemistry, organic mechanisms
R3.1	Redox extended — balancing in acidic/basic conditions, EMF calculations, electrochemical series problems	✔	✔	✔	✔	✔★	10–14	⭐⭐⭐⭐⭐
R3.3	Organic reactions extended — reaction pathways, mechanism drawing, identify reagents/conditions, multi-step synthesis	✔	✔	✔	✔	✔★	12–18	⭐⭐⭐⭐⭐ CERTAIN
STRUCTURE — Bonding, periodic trends, stoichiometry always in Paper 2
S1.1–S1.4	Stoichiometry & bonding extended — mole calculations, empirical formula, VSEPR analysis, polarity, properties from structure	✔	✔	✔	✔	✔★	10–16	⭐⭐⭐⭐⭐
AHL topics	Transition metals, SN1/SN2 mechanisms, NMR spectroscopy, advanced electrochemistry — AHL P2 always tests these AHL	—	—	—	—	✔★	12–18	⭐⭐⭐⭐⭐ AHL

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