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IB Demystified Examiners · Moderators · Mentors

The complete curriculum framework

IB Chemistry Higher Level, taught in the order it makes sense.

The complete Higher Level course re-presented as a single prerequisite-ordered teaching sequence — not six syllabus themes taught in the order they are printed. Every topic carries the depth to teach it to, the topics it connects to, and the investigation it prepares students for.

  • 27 topics
  • 6 phases
  • 180 h taught + 60 h practical
  • Paced to finish by January
01 — Higher Level

What this framework is

This framework re-presents the Chemistry Higher Level course as a single, prerequisite-ordered teaching sequence. It is built on three convictions: that topics should be taught in the order their dependencies require, that each should be taught to its full depth rather than its minimum, and that the connections between topics should be made explicit so students see chemistry as one connected subject rather than twenty-seven separate ones.

The intended outcome is a student taught deeply and connectedly enough to design and run their own scientific investigation, rather than one who — never having been shown the depth — reaches for a recipe from the internet.

Every topic is classified by the role it plays

Foundational

Self-contained, and a prerequisite for later topics.

Developmental

Extends one or more foundations.

Synthesis

Teachable at depth only once several strands are mature — entropy, equilibrium, acid–base equilibria, electrochemistry, organic pathways and structure determination. All placed late by design.

Why the sequence runs across the themes, not down them

The subject guide itself warns that Structure and Reactivity are meant to be taught in parallel rather than in sequence, because the two strands feed each other constantly: Gibbs energy sits in Reactivity 1 but is unreadable without the bonding and states work of Structure 1 and 2; stoichiometry sits in Reactivity 2 but belongs immediately after the mole. This framework acts on that advice. Structure and Reactivity topics are interleaved wherever the dependency requires it — which is why the spine runs horizontally across the syllabus themes rather than marching down them one at a time.

A note on the topic list. The 27 topics are the topic list from the IB Demystified DP Chemistry HL resource, re-ordered by dependency. Five of the larger entries have been split where the higher-level extension material depends on foundations that arrive later — covalent bonding from the advanced covalent models, organic families from spectroscopic identification, qualitative rates from formal kinetics, acids and bases from acid–base equilibria, and redox from electrochemistry. Nothing has been added and nothing dropped.

Inside this framework

02 — Higher Level

The teaching spine

Teach top to bottom — each phase is a prerequisite for the next. Colour shows each topic’s role in the sequence.

Phase A. Particulate foundations & quantitative chemistry

27 teaching hours

Nothing here depends on later material.

  • 1Particles & physical change
  • 2Atomic structure
  • 3Electron arrangement
  • 4The mole
  • 5Gases
  • 6Amount of change

Bonding, structure & periodicity

33 teaching hours

Shapes before polarity, polarity before forces.

  • 7Ionic bonding
  • 8Covalent bonding
  • 9Metallic bonding
  • 10Materials & structure
  • 11Periodicity

Energetics & the organic framework

29 teaching hours

Bond and lattice enthalpy are bonding quantities.

  • 12Enthalpy change
  • 13Energy cycles
  • 14Fuels & energy
  • 15Organic families

Rates, spontaneity & equilibrium

30 teaching hours

Entropy before equilibrium, so K arrives as thermodynamics.

  • 16Reaction rates
  • 17Kinetics & mechanisms
  • 18Entropy & spontaneity
  • 19Chemical equilibrium

Proton & electron transfer

33 teaching hours

Foundations first, then the equilibrium-dependent extensions.

  • 20Proton transfer
  • 21Acid–base equilibria
  • 22Redox & cells
  • 23Electrochemistry

Advanced bonding, mechanisms & structure determination

28 teaching hours

The genuine synthesis topics, placed last by design.

  • 24Advanced covalent models
  • 25Radical reactions
  • 26Organic pathways
  • 27Structure determination
Foundational Developmental Synthesis — taught late

180 h taught content + 60 h experimental programme = 240 h

03 — Higher Level

Why the capstones come last

Each synthesis topic can be taught at depth only once its feeders are in place. A gold arrow means ‘is a prerequisite for’.

27. Spectroscopic structure determination

  • 2 · Atomic structure — mass spectra
  • 8 · Covalent — polarity & bond types
  • 15 · Organic families — environments
  • 24 · Advanced covalent — benzene, sp²
  • 26 · Organic pathways — the products

27Structure determination

The true capstone: every structural model the course has built is tested against real spectra.

26. Organic reaction pathways

  • 15 · Organic families — functional groups
  • 24 · Advanced covalent — σ/π, benzene
  • 11 · Periodicity — electronegativity
  • 25 · Radical reactions — homolysis
  • 17 · Kinetics — rate-determining step

26Organic pathways

Curly arrows are meaningless until students can see where the electron density is.

21. Acid–base equilibria

  • 20 · Proton transfer — pH, strong vs weak
  • 19 · Chemical equilibrium — K
  • 4 · The mole — concentration
  • 6 · Amount of change — titration

21Acid–base equilibria

A buffer is an equilibrium problem wearing a lab coat.

23. Electrochemistry

  • 22 · Redox & cells — half-equations
  • 18 · Entropy & spontaneity — ΔG
  • 13 · Energy cycles — state functions
  • 11 · Periodicity — reactivity trends

23Electrochemistry

Where thermodynamics and redox finally meet: ΔG° = −nFE°.

19. Chemical equilibrium

  • 16 · Reaction rates — dynamic balance
  • 18 · Entropy & spontaneity — ΔG
  • 6 · Amount of change — ICE tables
  • 12 · Enthalpy — the temperature effect

19Chemical equilibrium

K is a thermodynamic quantity, not just an algebraic one.

How to read this

  • Right-hand boxes are the synthesis topics.
  • Left-hand entries are the topics they depend on.
  • A gold arrow means ‘is a prerequisite for’.
  • Every feeder sits earlier in the spine, so by the time a capstone is taught its feeders are done.
  • Entropy & spontaneity (18) is itself a synthesis topic — it feeds two of the five cards here, which is exactly why it is taught before them.
  • The whole argument in one view: sequence by dependency, not by theme number.
04 — Higher Level

The sequence at a glance

Every topic in teaching order, with its role and teaching hours. The suggested Year 1 / Year 2 boundary falls partway through Phase D and is adjustable.

All 27 Higher Level topics in prerequisite order.
#TopicSyllabus themeRoleHours
Phase A — Particulate foundations & quantitative chemistry (27 h)
1Particles, substances & physical changeStructure 1Foundational2 h
2Atomic structureStructure 1Foundational3 h
3Electron arrangementStructure 1Foundational6 h
4The mole & chemical amountsStructure 1Foundational7 h
5GasesStructure 1Developmental3 h
6Amount of chemical changeReactivity 2Developmental6 h
Phase B — Bonding, structure & periodicity (33 h)
7Ionic bondingStructure 2Foundational4 h
8Covalent bonding & molecular structureStructure 2Foundational10 h
9Metallic bondingStructure 2Developmental3 h
10Materials & structureStructure 2Developmental5 h
11Periodicity & element trendsStructure 3Developmental11 h
Phase C — Energetics & the organic framework (29 h)
12Enthalpy changeReactivity 1Foundational5 h
13Energy cycles & Born–HaberReactivity 1Developmental9 h
14Fuels & energy sourcesReactivity 1Developmental3 h
15Organic families, naming & isomerismStructure 3Foundational12 h
Phase D — Rates, spontaneity & equilibrium (30 h)
16Reaction rates & collision theoryReactivity 2Foundational7 h
17Kinetics: rate equations & mechanismsReactivity 2Developmental6 h
18Entropy & spontaneityReactivity 1Synthesis5 h
19Chemical equilibriumReactivity 2Synthesis12 h
Phase E — Proton & electron transfer (33 h)
20Proton transfer: acids, bases & pHReactivity 3Foundational9 h
21Acid–base equilibria: Ka, buffers & indicatorsReactivity 3Synthesis7 h
22Electron transfer: redox & cellsReactivity 3Foundational9 h
23Electrochemistry: E°, ΔG & electrolysisReactivity 3Synthesis8 h
Phase F — Advanced bonding, mechanisms & structure determination (28 h)
24Advanced covalent modelsStructure 2Developmental8 h
25Radical reactionsReactivity 3Developmental3 h
26Organic reaction pathways & mechanismsReactivity 3Synthesis9 h
27Spectroscopic structure determinationStructure 3Synthesis8 h
Total taught content180 h
05 — Higher Level

The 27 topics in depth

Each topic carries its teaching depth, its interconnections with other topics, and the investigative angle through which it prepares a student for the scientific investigation. Select a topic to open it.

Phase A · 27 hours

Particulate foundations & quantitative chemistry

Nothing here depends on later material, so it is taught first. The particle model, the language of the atom and the mole are front-loaded because every later structure, energy change and rate is counted and explained through them. Stoichiometry is pulled forward from Reactivity 2 to sit immediately after the mole, where it belongs.

Particles, substances & physical change Foundational 2 h
Teach to this depth
Establish elements, compounds and mixtures as a classification with consequences, not vocabulary: why a mixture can be separated physically and a compound cannot. Cover solvation, filtration, recrystallisation, evaporation, distillation and chromatography as choices a chemist makes for a reason, and distinguish homogeneous from heterogeneous mixtures. Treat kinetic molecular theory as a model, name every change of state including sublimation and deposition, use state symbols correctly from the first lesson, and establish temperature in kelvin as a measure of average kinetic energy.
Connects to
Separation technique choice returns as an intermolecular-forces question in covalent bonding; kinetic energy returns as the Maxwell–Boltzmann distribution; the endothermic and exothermic nature of changes of state returns in enthalpy.
Investigation angle
Purification and purity determination; separation efficiency measured against a real mixture.
Atomic structure Foundational 3 h
Teach to this depth
Build the nuclear model, the relative masses and charges of the subatomic particles, and fluent use of nuclear symbols to deduce protons, neutrons and electrons in atoms and ions. Treat isotopes as a physical-property story as well as a mass one, calculate non-integer relative atomic masses from abundance data, and at HL read mass spectra directly for identity and relative abundance.
Connects to
Atomic number orders the periodic table; isotopic mass feeds every mole calculation; the mass spectrum reappears in Phase F as the first tool of organic structure determination, so flag that forward link explicitly here.
Investigation angle
Isotope-abundance analysis from spectral data; isotopic tracers as mechanistic evidence.
Electron arrangement Foundational 6 h
Teach to this depth
Move from the electromagnetic spectrum to emission spectra as evidence for discrete energy levels, distinguishing continuous from line spectra and explaining convergence. Establish the 2n² rule, the s, p, d and f sublevels, orbital shapes, and confident application of the Aufbau principle, Hund’s rule and the Pauli exclusion principle up to Z = 36, including the chromium and copper exceptions and orbital diagrams. At HL, connect the convergence limit to ionisation, calculate a first ionisation energy from spectral data, and read successive ionisation energies as direct evidence of shell structure.
Connects to
This is the single most load-bearing topic in the Structure strand: periodicity, ionic charge, transition-element colour and variable oxidation state, hybridisation and formal charge all reduce to electron configuration. Ionisation energy is the quantitative link between configuration and periodic trend.
Investigation angle
Flame-test and emission-spectrum work with a spectroscope or database; the relationship between convergence limit and ionisation energy.
The mole & chemical amounts Foundational 7 h
Teach to this depth
Establish the mole as the SI unit of amount and the Avogadro constant as a counting device, and drill conversion between mass, moles and particles until it is automatic. Cover relative atomic and formula mass, molar mass, empirical and molecular formulas from percentage composition and combustion data, and molar concentration in both g dm⁻³ and mol dm⁻³ with confident use of square brackets. Introduce Avogadro’s law and standard-solution preparation.
Connects to
Everything quantitative downstream: reacting masses, gas volumes, titration, K expressions, pH and cell stoichiometry. Weakness here surfaces later as apparent weakness in equilibrium or acid–base work, so it is worth over-securing.
Investigation angle
Empirical formula by mass change on combustion or hydration; concentration determination by calibration curve — a reliable, well-scoped investigation with genuinely propagable uncertainties.
Gases Developmental 3 h
Teach to this depth
State the assumptions of the ideal gas model explicitly and treat them as claims that can fail. Investigate the pressure–volume–temperature relationships graphically, use molar gas volume at STP, and solve problems with PV = nRT and the combined gas law in SI units only. Explain qualitatively why real gases deviate at low temperature and high pressure.
Connects to
Deviation from ideality is an intermolecular-forces argument, so it is revisited in covalent bonding; molar gas volume feeds gas stoichiometry; the model-and-its-limits framing is a useful first encounter with the nature of science.
Investigation angle
Molar mass of a gas from experimental PV, T and mass data; quantifying deviation from ideal behaviour.
Amount of chemical change Developmental 6 h
Teach to this depth
Balance equations reliably, including ionic equations, then work the full stoichiometric toolkit: reacting masses, gas volumes, solution concentration, limiting and excess reactant identified by calculation rather than inspection, theoretical and percentage yield, and atom economy as a green-chemistry measure distinct from yield.
Connects to
Pulled forward from Reactivity 2 to sit next to the mole because every later quantitative topic assumes it. Limiting reactant reasoning returns in calorimetry; the mole ratio underwrites titration, ICE tables and electrolysis calculations.
Investigation angle
Percentage yield of a real synthesis and an honest account of where the missing mass went; comparing atom economy across two routes to the same product.

Phase B · 33 hours

Bonding, structure & periodicity

A strict chain: ions before lattices, Lewis structures before shapes, shapes before polarity, and polarity before intermolecular forces. Periodicity closes the phase rather than opening the course, because a trend is only explicable once electron configuration, ionic charge and bonding type are all in place.

Ionic bonding Foundational 4 h
Teach to this depth
Predict ionic charge from electron configuration rather than from a memorised group rule, including the variable charges of transition elements. Establish the ionic bond as electrostatic attraction, name and write formulas for binary and polyatomic compounds fluently, and explain volatility, conductivity and solubility from the three-dimensional lattice. Introduce lattice enthalpy as a measure of ionic bond strength governed by ionic radius and charge.
Connects to
Charge prediction comes straight from electron arrangement; lattice enthalpy is the quantity the Born–Haber cycle is built to find; the polyatomic ions learned here are the conjugate bases met in Phase E.
Investigation angle
Conductivity, melting point or solubility measured across a series of ionic compounds and explained by charge and radius.
Covalent bonding & molecular structure Foundational 10 h
Teach to this depth
The largest foundational block in the course, and worth every hour. Establish the covalent bond electrostatically, deduce Lewis formulas for up to four electron pairs including species that break the octet, and relate bond number to bond length and strength. Identify coordination bonds. Apply VSEPR to predict electron-domain and molecular geometry with the effect of lone pairs and multiple bonds on bond angle. Deduce bond polarity from electronegativity and net dipole from geometry, insisting that students reason from shape rather than guess. Cover covalent network structures and carbon’s allotropes, then the full intermolecular-forces hierarchy — London, dipole-induced dipole, dipole–dipole and hydrogen bonding — and use it to explain volatility, conductivity and solubility. Close with chromatography and RF values as an application of exactly those forces.
Connects to
Deviation of real gases from ideality; the boiling-point trends of homologous series; solubility and extraction in organic chemistry; IR activity in Phase F; and the entire structure–property argument of topic 10.
Investigation angle
Boiling point or volatility against molecular structure across a controlled series; chromatographic separation with RF analysis; solubility as a test of a polarity prediction.
Metallic bonding Developmental 3 h
Teach to this depth
Define the metallic bond as attraction between a cation lattice and delocalised electrons, and explain electrical and thermal conductivity and malleability from it. Explain melting-point trends in s- and p-block metals from cation charge and electron density, and at HL account for the high melting points and conductivity of transition elements through delocalised d-electrons.
Connects to
Completes the third vertex of the bonding triangle used in topic 10; non-directional bonding is the reason alloys work; the transition-element treatment is picked up again in periodicity.
Investigation angle
Conductivity or hardness across a metal series; the effect of composition on an alloy property.
Materials & structure Developmental 5 h
Teach to this depth
Present bonding as a continuum rather than three boxes, and use the bonding triangle with electronegativity data to place a binary compound and predict its properties. Explain alloy behaviour through non-directional bonding, and cover polymers as macromolecules: addition polymerisation from alkene monomers, and at HL condensation polymerisation forming polyamides and polyesters with loss of a small molecule.
Connects to
This is the first genuine synthesis of the bonding strand, so it is placed after all three models. Condensation polymerisation reaches forward to functional groups and back to atom economy — addition polymerisation is 100% atom-economical and that is worth proving.
Investigation angle
Structure–property testing of plastics; biodegradability; composition and strength in an alloy or composite.
Periodicity & element trends Developmental 11 h
Teach to this depth
Read the periodic table as a consequence of electron configuration: periods as occupied energy levels, groups as valence-electron counts, blocks as sublevels. Explain — not merely state — the periodicity of atomic and ionic radius, ionisation energy, electron affinity and electronegativity. Cover the reactions of group 1 with water and group 17 with halide ions, and the continuum from basic metal oxides through amphoteric to acidic non-metal oxides, including acid rain and ocean acidification. Establish oxidation states as a bookkeeping device with clear rules and known exceptions. At HL add the discontinuities in first ionisation energy as evidence for sublevels, and the full transition-element treatment: variable oxidation state from close successive ionisation energies, catalytic and magnetic behaviour, complex-ion formation and the origin of colour in d-orbital splitting.
Connects to
Electron arrangement supplies the explanation; oxidation states are the prerequisite for all redox work in Phase E; oxide acidity previews proton transfer; complex-ion formation is a Lewis acid–base reaction met again in Phase F.
Investigation angle
Trends in reactivity down a group measured rather than watched; colorimetric determination of a transition-metal complex concentration; catalytic activity compared across d-block ions.

Phase C · 29 hours

Energetics & the organic framework

Energetics follows bonding because bond enthalpy and lattice enthalpy are bonding quantities, and Born–Haber cycles are unteachable before ionisation energy and lattice structure. Organic families sit at the end of this phase so that the naming, isomerism and functional-group vocabulary is fluent long before the mechanisms of Phase F — and so that the fuels work has real molecules to talk about.

Enthalpy change Foundational 5 h
Teach to this depth
Separate heat from temperature carefully, since the confusion behind most calorimetry errors starts here. Establish system and surroundings, conservation of energy, and the sign convention for exothermic and endothermic change with correctly labelled energy profiles including activation energy. Define standard enthalpy changes and their conditions, and run calorimetry properly: q = mcΔT, the assumptions built into it, heat loss, and the temperature-extrapolation correction.
Connects to
The bond-making and bond-breaking account of ΔH depends on covalent bonding; ΔH feeds Hess cycles, Gibbs energy and the temperature dependence of K; calorimetry is one of the best-supported investigation techniques available in a school laboratory.
Investigation angle
Enthalpy of neutralisation, solution, combustion or displacement, with a serious treatment of heat loss and uncertainty propagation — among the most reliably high-scoring investigation designs.
Energy cycles & Born–Haber Developmental 9 h
Teach to this depth
Establish Hess’s law as a consequence of enthalpy being a state function, and calculate ΔH by three routes: cycles, enthalpies of formation, and average bond enthalpies — comparing the answers and explaining why the bond-enthalpy route disagrees. Cover enthalpy of combustion and formation precisely. At HL construct Born–Haber cycles to find lattice enthalpy, compare experimental with theoretical lattice enthalpies as evidence of covalent character, and handle enthalpy of solution through hydration enthalpies.
Connects to
Draws ionisation energy from electron arrangement, electron affinity and atomisation from periodicity, and lattice enthalpy from ionic bonding — which is precisely why it cannot be taught in the opening term. Feeds directly into Gibbs energy.
Investigation angle
Verifying Hess’s law experimentally through an indirect route; comparing calculated and measured enthalpies of formation.
Fuels & energy sources Developmental 3 h
Teach to this depth
Compare complete and incomplete combustion and their products, including the toxicity and particulate consequences. Relate carbon dioxide output to the greenhouse effect through molecular vibration and IR absorption rather than assertion, and evaluate biofuels and fuel cells on evidence — energy density, carbon balance, practical limitations — rather than on enthusiasm.
Connects to
Uses combustion enthalpy from topic 13; the IR-absorption argument returns as a spectroscopic technique in Phase F; fuel cells return as electrochemistry in Phase E.
Investigation angle
Comparative energy density of fuels by calorimetry; assessing a biofuel claim against measured data.
Organic families, naming & isomerism Foundational 12 h
Teach to this depth
Interconvert empirical, molecular, condensed, full structural and skeletal formulas, and build real or virtual 3D models rather than relying on flat drawings. Identify all the required functional groups by name and structure, and the homologous series they define, explaining the trend in melting and boiling points from intermolecular forces rather than restating it. Apply IUPAC nomenclature systematically to straight- and branched-chain compounds up to six carbons. Cover structural isomerism — chain, position and functional group — and primary, secondary and tertiary classification. At HL add stereoisomerism: cis-trans in non-cyclic alkenes and C3/C4 cycloalkanes, the chiral carbon, enantiomers as non-superimposable mirror images drawn with wedge-dash notation, optical activity and racemic mixtures.
Connects to
Boiling-point trends are the intermolecular-forces work of topic 8 applied; functional-group identity determines every mechanism in Phase F; the primary/secondary/tertiary distinction decides both oxidation products and substitution mechanism; 3D structure is what NMR and enantiomer questions ultimately test.
Investigation angle
Physical-property trends across a homologous series; isomer separation or identification; optical rotation where a polarimeter is available.

Phase D · 30 hours

Rates, spontaneity & equilibrium

Rates open the phase because dynamic equilibrium is defined through them. Entropy and spontaneity are placed deliberately before equilibrium, so that K arrives as a thermodynamic quantity related to ΔG rather than as an algebraic expression students learn to fill in.

Reaction rates & collision theory Foundational 7 h
Teach to this depth
Define rate operationally and measure it several ways — mass loss, gas volume, colour change, conductivity, clock reactions — deriving rate from the gradient of a real graph including the initial-rate tangent. Build collision theory properly: frequency, energy and orientation, with activation energy as the threshold. Interpret and sketch Maxwell–Boltzmann distributions for changes in temperature and for a catalyst, insisting on correct axis labels and shaded area beyond Ea, and explain catalysis as an alternative pathway.
Connects to
Kinetic energy and temperature from topic 1; the energy profile from enthalpy; the distribution curve is the explanation behind the temperature effect on K; catalysts return in the transition-element and fuel-cell work.
Investigation angle
The classic strong design: rate against concentration, temperature, surface area or catalyst, with initial rates taken from properly drawn tangents and a defended method of measurement.
Kinetics: rate equations & mechanisms Developmental 6 h
Teach to this depth
Determine order from experimental data, both graphically and by inspection of initial rates, and write the rate equation with correct units for k. Distinguish order from stoichiometric coefficient as a matter of principle. Cover multi-step mechanisms, molecularity, the rate-determining step, and the requirement that a proposed mechanism be consistent with both the rate equation and the overall equation. Develop the Arrhenius equation in both forms, extracting Ea from the gradient of an ln k against 1/T plot.
Connects to
The linearised Arrhenius plot is the course’s clearest use of logarithms; mechanism proposal is the intellectual bridge to the organic pathways of Phase F, where the SN1/SN2 distinction is precisely a kinetics argument.
Investigation angle
Determining order and rate constant for a real reaction; extracting an activation energy from a temperature series and comparing it with literature.
Entropy & spontaneity Synthesis 5 h
Teach to this depth
Establish entropy as a measure of the dispersal of energy and matter, predict the sign of ΔS from changes in state and mole count, and calculate ΔS° from standard entropies. Develop ΔG° = ΔH° − TΔS°, use it to determine spontaneity, work through the four sign combinations, and find the temperature at which a reaction becomes spontaneous. Establish ΔG° = −RT ln K as the bridge to the next topic.
Connects to
Needs ΔH from Phase C and the particle-disorder intuition from Phase A; feeds equilibrium immediately and electrochemistry in Phase E through ΔG° = −nFE°. This is the topic that turns thermodynamics from arithmetic into prediction.
Investigation angle
Determining ΔG, ΔH and ΔS for a solubility or cell system from temperature-dependent measurements.
Chemical equilibrium Synthesis 12 h
Teach to this depth
Establish dynamic equilibrium experimentally as well as verbally — rates equal, concentrations constant, closed system. Write K expressions correctly, interpret magnitude in terms of extent, and apply Le Châtelier’s principle to concentration, pressure and temperature changes, being clear that a catalyst changes neither position nor K. At HL work full ICE-table calculations including the approximation and its validity, use the reaction quotient Q to predict direction of change, and close by relating K to ΔG°, so that the temperature dependence of K is explained rather than asserted. Apply the whole apparatus to an industrial process such as the Haber or Contact process where kinetic and thermodynamic demands conflict.
Connects to
Rates supply the dynamic definition, stoichiometry supplies the ICE table, Gibbs energy supplies the explanation. Everything in Phase E — Ka, Kb, Kw, buffers, solubility — is this topic in a new costume, which is why it must be secure first.
Investigation angle
Determining K for an esterification or a coloured equilibrium by colorimetry; the temperature dependence of K used to extract ΔH.

Phase E · 33 hours

Proton & electron transfer

Both mechanisms are split in two: the qualitative and quantitative foundations first, then the equilibrium- and thermodynamics-dependent extensions. Buffers and standard electrode potentials are not harder versions of acids and redox — they are equilibrium and Gibbs energy applied, and they fail if taught before those.

Proton transfer: acids, bases & pH Foundational 9 h
Teach to this depth
Establish the Brønsted–Lowry model, conjugate acid–base pairs and amphiprotic species, distinguishing amphiprotic from amphoteric. Cover the reactions of acids with metals, bases, carbonates and hydrogencarbonates, and neutralisation with correct ionic equations. Develop pH and pOH as logarithmic scales — including what a one-unit change really means — with Kw linking them, and treat the strong/weak distinction as one of dissociation extent, supported by conductivity and rate evidence rather than assertion. Run titrations properly and interpret pH curves for all four acid–base combinations, identifying equivalence point, half-equivalence and buffer region.
Connects to
Concentration from the mole; titration stoichiometry from topic 6; oxide acidity from periodicity; and the logarithmic scale connects to the log work in ionisation energy. The curve features identified here are quantified in the next topic.
Investigation angle
Titrimetric determination of the concentration or purity of a household or food product; pH-probe titration curves analysed for equivalence and buffer regions.
Acid–base equilibria: Ka, buffers & indicators Synthesis 7 h
Teach to this depth
Develop Ka, Kb, pKa and pKb with the relationship KaKb = Kw, and calculate the pH of weak acids and bases with the assumptions stated and checked. Explain salt hydrolysis from the strength of the parent acid and base. Treat indicators as weak acids whose colour change is an equilibrium shift, and select one by matching pKa to the equivalence pH of the specific curve. Build buffers from first principles — composition, the mechanism of resistance in both directions, and pH calculation before and after addition of acid or base.
Connects to
Straight application of equilibrium; the half-equivalence point of topic 20 is where pH = pKa, which is the neatest cross-topic link in the strand; buffer chemistry connects to biological and environmental systems.
Investigation angle
Determining Ka from a titration curve; buffer capacity measured against composition and dilution — an excellent, well-bounded quantitative investigation.
Electron transfer: redox & cells Foundational 9 h
Teach to this depth
Define oxidation and reduction by electron transfer and track it with oxidation states, identifying oxidising and reducing agents confidently. Deduce and combine half-equations in acidic and basic conditions, including balancing with H⁺, OH⁻ and H₂O. Establish the activity series from displacement evidence, cover reactions of acids with metals, and build voltaic cells: electrode identity, electron and ion flow, salt bridge function and cell notation, alongside primary and secondary cells. Cover electrolysis of molten salts and the oxidation of alcohols and reduction of carbonyls as redox in organic disguise.
Connects to
Oxidation states come from periodicity; the alcohol oxidation series links directly to the primary/secondary/tertiary classification of topic 15; the activity series is the qualitative version of the electrode potentials that follow.
Investigation angle
Redox titration to determine the concentration of vitamin C, iron or bleach; the effect of a variable on the voltage or output of a home-made cell.
Electrochemistry: E°, ΔG & electrolysis Synthesis 8 h
Teach to this depth
Establish the standard hydrogen electrode as the reference and read standard electrode potentials as a quantified activity series, calculating E°cell and predicting feasibility. Connect spontaneity to thermodynamics through ΔG° = −nFE° and the link back to K, so all three measures of feasibility are seen as one. Cover the electrolysis of aqueous solutions with the competing-reaction analysis at each electrode, the factors that decide the product, Faraday’s quantitative treatment, and electroplating.
Connects to
Needs Gibbs energy from topic 18 and redox from topic 22 — it is placed here for exactly that reason. Electrolysis stoichiometry reuses the mole; fuel cells return from topic 14 with the chemistry now available to explain them.
Investigation angle
Measuring cell potential against concentration or temperature; determining Faraday’s constant by electrolysis; electroplating efficiency against current and time.

Phase F · 28 hours

Advanced bonding, mechanisms & structure determination

The genuine synthesis topics, placed last by design. Mechanisms require the advanced bonding model to be secure, and structure determination is the true capstone: it asks a student to reconstruct a molecule from evidence, drawing on atomic structure, bonding, polarity, functional groups and reaction pathways at once.

Advanced covalent models Developmental 8 h
Teach to this depth
Deduce resonance structures and treat delocalisation as a real redistribution of electron density, then build the case for benzene’s structure from physical and chemical evidence — bond lengths, enthalpy of hydrogenation, resistance to addition — as a model-building exercise rather than a fact. Cover expanded octets with five and six electron domains and the associated geometries, and use formal charge to choose between competing Lewis formulas. Establish sigma and pi bonding from orbital overlap and hybridisation (sp, sp², sp³), and drill the two-way link between Lewis formula, electron domains, geometry and hybridisation.
Connects to
Extends topic 8 but is deliberately separated from it, because hybridisation is only meaningful once orbitals, geometry and organic structure are all fluent. Delocalisation explains benzene’s unreactivity in topic 26 and the stability of carboxylate and nitrate ions in Phase E.
Investigation angle
Computational modelling of geometry and orbital overlap; resonance energy from measured enthalpies of hydrogenation.
Radical reactions Developmental 3 h
Teach to this depth
Define the radical through homolytic fission and contrast it explicitly with the heterolytic fission that produces ions. Work the full free-radical halogenation of alkanes as a three-stage chain — initiation, propagation, termination — with the UV requirement justified by bond enthalpy, and discuss why the reaction gives a mixture of products and what that means for its synthetic usefulness.
Connects to
Bond enthalpy from topic 13 sets the initiation condition; the homolytic/heterolytic contrast is the organising distinction for topic 26; chain reactions connect to ozone depletion and atmospheric chemistry.
Investigation angle
Product distribution in a radical halogenation; UV-initiated reactions and photochemical rate studies.
Organic reaction pathways & mechanisms Synthesis 9 h
Teach to this depth
Establish nucleophile, electrophile and heterolytic fission, and teach curly-arrow notation as a statement about electron movement that must be drawn correctly to count. Develop nucleophilic substitution of halogenoalkanes through both SN1 and SN2, with the choice justified by substrate class, steric access, carbocation stability and — critically — the observed rate equation. Cover electrophilic addition to alkenes including unsymmetrical cases and Markovnikov orientation explained by carbocation stability, and electrophilic substitution in benzene explained by delocalisation. Frame Lewis acid–base theory and coordination-bond formation as the general case that contains all of this. Finish by having students construct multi-step synthetic routes between named functional groups.
Connects to
Functional groups and isomerism from topic 15, polarity from topic 8, delocalisation and hybridisation from topic 24, the rate-determining step from topic 17, and radical contrast from topic 25. It is the most heavily fed topic in the course.
Investigation angle
Comparing substitution rates across primary, secondary and tertiary halogenoalkanes or across the halogens; yield and selectivity in a two-step synthesis.
Spectroscopic structure determination Synthesis 8 h
Teach to this depth
Read mass spectra for the molecular ion and deduce structure from fragmentation patterns. Interpret the functional-group region of an IR spectrum against the data booklet, and connect IR activity back to dipole change and the greenhouse argument of topic 14. Develop ¹H NMR fully: number of signals as chemical environments, chemical shift, integration, and splitting patterns read through the n+1 rule. Then teach the skill the examination actually rewards — combining MS, IR, NMR and molecular formula to arrive at one structure, with the reasoning written out and the alternatives explicitly eliminated.
Connects to
Mass spectrometry from topic 2, bond polarity from topic 8, functional groups and 3D structure from topic 15, benzene and hybridisation from topic 24, and reaction products from topic 26. Placed last, the analysis finally has a full toolkit to draw on — the central argument of this entire framework.
Investigation angle
Confirming the identity or purity of a synthesised product by spectroscopy; using database spectra to identify an unknown, with the elimination reasoning made explicit.
06 — Higher Level

Time allocation & two-year pacing

The IB recommends 240 teaching hours for a Higher Level subject — for Chemistry HL, 180 hours of taught syllabus content plus a 60-hour experimental programme comprising 40 hours of practical work, the 10-hour collaborative sciences project and the 10-hour scientific investigation. The allocations above distribute the 180 content hours across all 27 topics; below they are reconciled to the official per-theme totals and paced so that teaching is complete by the end of January in Year 2.

Reconciliation to the official IB allocation

IB syllabus themeOfficial IB hoursAllocated here
Structure 1 — Models of the particulate nature of matter21 h21 h
Structure 2 — Models of bonding and structure30 h30 h
Structure 3 — Classification of matter31 h31 h
Reactivity 1 — What drives chemical reactions?22 h22 h
Reactivity 2 — How much, how fast and how far?31 h31 h
Reactivity 3 — What are the mechanisms of chemical change?45 h45 h
Taught content subtotal180 h180 h
Practical work40 h40 h
Collaborative sciences project10 h10 h
Scientific investigation (IA)10 h10 h
HL course total240 h240 h

Because this framework splits five syllabus subtopics and re-orders the sequence, individual topics do not map one-to-one onto the guide’s per-subtopic hours; the totals for each theme match the guide exactly.

The two-year pacing plan

Built on roughly five teaching hours per week. The cumulative column tracks progress toward the 240-hour total; the gold rows fall outside the teaching budget.

PeriodFocusHoursCumulative
Year 1
Autumn termPhase A — particulate foundations & quantitative chemistry · begin the practical programme (10 h)3737
Spring termPhase B — bonding, structure & periodicity · practical work (12 h)4582
Summer termPhase C — energetics & the organic framework · begin Phase D (rates & kinetics) · collaborative sciences project (10 h) · practical work (6 h)58140
Year 2 (to end January)
Autumn termFinish Phase D (entropy & equilibrium) · Phase E — proton & electron transfer · run & write the scientific investigation (10 h) · practical work (12 h)72212
To end of JanuaryPhase F — advanced bonding, mechanisms & structure determination28240
February – AprilDedicated revision: past papers, Paper 1A / 1B / 2 drills and timed mocks (additional to the 240 teaching hours)——
MayIB examinations——

Revision time (February–April) is deliberately additional to the 240 teaching hours, in line with the subject guide’s reminder that adequate time must be set aside for examination revision. The practical programme is distributed across the two years rather than blocked, so that each technique is met alongside the theory it belongs to — and so that students have run enough independent work to design a scientific investigation of their own by the summer of Year 1.

Sequence by dependency, not by theme number

Structure determination comes last for a reason: by then a student has every model the course can give them, and can reconstruct a molecule from evidence alone.

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