International Baccalaureate · IB Diploma

Chemistry · HL

Papers, samples and curriculum documents for this course.

Handouts, exercise sheets and slides

Shared topic documents retain their source course and topic titles. Use your chosen board’s specification for coverage, tier and exam requirements.

Handouts · A-Level Chemistry (37)

Exercise sheets · A-Level Chemistry (90)

Presentation slides · A-Level Chemistry (37)

Course units and learning goals

These lessons teach selected course objectives. Check the remaining coverage gaps; the material is not a complete preparation programme.

Lessons →Vocabulary practice →

Structure 1.1 · Introduction to the particulate nature of matter

Temperature on the kelvin scale.
At fixed amount and volume, pressure is proportional to kelvin temperature. At fixed temperature and amount, pressure is inversely proportional to volume. State which quantities are fixed before choosing a relationship.
Use approved apparatus with a temperature range and pressure limit set by the teacher. Allow thermal equilibrium and record pressure against kelvin temperature. Never heat an improvised sealed vessel.

absolute temperature: Temperature on the kelvin scale
ideal gas: A gas model with specified simplifying assumptions

Structure 1.2 · The nuclear atom

Attraction between oppositely charged ions.
To explain a bulk property, name the structure, particles, forces and mobile charge carriers. Simple molecular substances can have strong covalent bonds inside molecules but weak attractions between molecules.
Compare substances using evidence such as melting point, conductivity when solid and molten, and solubility. One property rarely proves a structure; use a pattern of evidence.

ionic bond: Attraction between oppositely charged ions
delocalized electron: An electron not confined to one atom or bond

Structure 1.3 · Electron configurations

Attraction between oppositely charged ions.
To explain a bulk property, name the structure, particles, forces and mobile charge carriers. Simple molecular substances can have strong covalent bonds inside molecules but weak attractions between molecules.
Compare substances using evidence such as melting point, conductivity when solid and molten, and solubility. One property rarely proves a structure; use a pattern of evidence.

ionic bond: Attraction between oppositely charged ions
delocalized electron: An electron not confined to one atom or bond

Structure 1.4 · Counting particles by mass: the mole

The SI unit of amount of substance.
Calculate the amount available for each reactant and divide by its coefficient. The smaller ratio limits the reaction. Use that reactant to calculate the maximum product before comparing actual yield.
Write the balanced equation first, include units in molar masses, then convert each given mass or solution volume into amount. Convert cubic centimetres to cubic decimetres before using concentration in moles per cubic decimetre.

mole: The SI unit of amount of substance
limiting reagent: The reactant that limits the possible product amount

Structure 1.5 · Ideal gases

Temperature on the kelvin scale.
At fixed amount and volume, pressure is proportional to kelvin temperature. At fixed temperature and amount, pressure is inversely proportional to volume. State which quantities are fixed before choosing a relationship.
Use approved apparatus with a temperature range and pressure limit set by the teacher. Allow thermal equilibrium and record pressure against kelvin temperature. Never heat an improvised sealed vessel.

absolute temperature: Temperature on the kelvin scale
ideal gas: A gas model with specified simplifying assumptions

Structure 2.1 · The ionic model

Attraction between oppositely charged ions.
To explain a bulk property, name the structure, particles, forces and mobile charge carriers. Simple molecular substances can have strong covalent bonds inside molecules but weak attractions between molecules.
Compare substances using evidence such as melting point, conductivity when solid and molten, and solubility. One property rarely proves a structure; use a pattern of evidence.

ionic bond: Attraction between oppositely charged ions
delocalized electron: An electron not confined to one atom or bond

Structure 2.2 · The covalent model

Attraction between oppositely charged ions.
To explain a bulk property, name the structure, particles, forces and mobile charge carriers. Simple molecular substances can have strong covalent bonds inside molecules but weak attractions between molecules.
Compare substances using evidence such as melting point, conductivity when solid and molten, and solubility. One property rarely proves a structure; use a pattern of evidence.

ionic bond: Attraction between oppositely charged ions
delocalized electron: An electron not confined to one atom or bond

Structure 2.3 · The metallic model

Attraction between oppositely charged ions.
To explain a bulk property, name the structure, particles, forces and mobile charge carriers. Simple molecular substances can have strong covalent bonds inside molecules but weak attractions between molecules.
Compare substances using evidence such as melting point, conductivity when solid and molten, and solubility. One property rarely proves a structure; use a pattern of evidence.

ionic bond: Attraction between oppositely charged ions
delocalized electron: An electron not confined to one atom or bond

Structure 2.4 · From models to materials

Attraction between oppositely charged ions.
To explain a bulk property, name the structure, particles, forces and mobile charge carriers. Simple molecular substances can have strong covalent bonds inside molecules but weak attractions between molecules.
Compare substances using evidence such as melting point, conductivity when solid and molten, and solubility. One property rarely proves a structure; use a pattern of evidence.

ionic bond: Attraction between oppositely charged ions
delocalized electron: An electron not confined to one atom or bond

Structure 3.1 · The periodic table: classification of elements

Attraction between oppositely charged ions.
To explain a bulk property, name the structure, particles, forces and mobile charge carriers. Simple molecular substances can have strong covalent bonds inside molecules but weak attractions between molecules.
Compare substances using evidence such as melting point, conductivity when solid and molten, and solubility. One property rarely proves a structure; use a pattern of evidence.

ionic bond: Attraction between oppositely charged ions
delocalized electron: An electron not confined to one atom or bond

Structure 3.2 · Functional groups: classification of organic compounds

An atom group determining characteristic reactions.
Distinguish addition, substitution, oxidation and polymerization by tracing bonds before and after reaction. Conditions and reagents belong to the reaction arrow; they are not interchangeable labels.
Draw displayed or structural formulae with the correct number of bonds at each carbon. Use a carbon count to check a proposed synthesis. At advanced level, track reagents and conditions through multistep routes.

functional group: An atom group determining characteristic reactions
isomer: A compound sharing a formula but differing in structure

Reactivity 1.1 · Measuring enthalpy change

Transferring energy to the surroundings.
Use energy transferred = mass × specific heat capacity × temperature change. Convert joules to kilojoules before dividing by reaction amount. An exothermic molar enthalpy change has a negative sign.
Use insulation and a lid, measure starting temperatures consistently, stir, and record a temperature-time series. Estimate the reaction temperature from an appropriate extrapolation rather than ignoring cooling during measurement.

exothermic: Transferring energy to the surroundings
enthalpy change: Heat change at constant pressure for a stated process

Reactivity 1.2 · Energy cycles in reactions

Transferring energy to the surroundings.
Use energy transferred = mass × specific heat capacity × temperature change. Convert joules to kilojoules before dividing by reaction amount. An exothermic molar enthalpy change has a negative sign.
Use insulation and a lid, measure starting temperatures consistently, stir, and record a temperature-time series. Estimate the reaction temperature from an appropriate extrapolation rather than ignoring cooling during measurement.

exothermic: Transferring energy to the surroundings
enthalpy change: Heat change at constant pressure for a stated process

Reactivity 1.3 · Energy from fuels

Assessment across production, use and disposal.
Define the functional unit before comparing products. The same delivered service, such as carrying one litre of water a hundred times, is fairer than comparing one object with another regardless of lifetime.
List system boundaries, energy sources and assumptions. Compare water demand, emissions and waste separately before making a judgement. Explain whose priorities affect the decision and where the data are uncertain.

life-cycle assessment: Assessment across production, use and disposal
functional unit: The common service used for a fair comparison

Reactivity 1.4 · Entropy and spontaneity

A state property related to energy dispersal and accessible arrangements.
Use ΔG = ΔH - TΔS with consistent energy units. A negative Gibbs energy change indicates thermodynamic favourability for the stated conditions, not a fast rate. An activation barrier can make a favourable process slow.
State whether values are standard-state quantities and record temperature in kelvin. Convert entropy from joules per kelvin per mole into kilojoules per kelvin per mole when enthalpy is in kilojoules per mole.

entropy: A state property related to energy dispersal and accessible arrangements
Gibbs energy: A thermodynamic quantity combining enthalpy and entropy contributions

Reactivity 2.1 · How much? The amount of chemical change

The SI unit of amount of substance.
Calculate the amount available for each reactant and divide by its coefficient. The smaller ratio limits the reaction. Use that reactant to calculate the maximum product before comparing actual yield.
Write the balanced equation first, include units in molar masses, then convert each given mass or solution volume into amount. Convert cubic centimetres to cubic decimetres before using concentration in moles per cubic decimetre.
The volume delivered between two burette readings.
Calculate the known amount first, apply the stoichiometric ratio, then divide by the unknown solution volume in cubic decimetres. Use concordant titres as required by the school method and report the accepted values.
Rinse the burette with its solution and the pipette with the solution it transfers. Rinse the flask with distilled water. Add titrant slowly near the endpoint, swirl, and read the meniscus at eye level. Use a white tile and appropriate eye protection.

mole: The SI unit of amount of substance
limiting reagent: The reactant that limits the possible product amount
titre: The volume delivered between two burette readings
equivalence point: The point of stoichiometric reaction completion

Reactivity 2.2 · How fast? The rate of chemical change

The energy barrier for a reaction pathway.
A product-time graph has a steeper gradient where rate is larger. A tangent estimates instantaneous rate; a secant gives average rate over an interval. The final plateau reflects the total collected product under the stated conditions.
For gas production, check apparatus for leaks, start timing consistently and record volume at regular intervals. Keep concentration, reactant amount and surface area controlled when changing temperature.

activation energy: The energy barrier for a reaction pathway
rate: Change in a measured quantity per unit time

Reactivity 2.3 · How far? The extent of chemical change

A state with equal forward and reverse reaction rates.
A concentration or pressure change disturbs the balance. The system responds toward a new equilibrium. Temperature changes can also change the equilibrium constant; a catalyst changes how quickly equilibrium is reached.
State the balanced equation and whether the forward reaction is exothermic before predicting a temperature effect. Count gas coefficients when considering pressure; pressure has no composition effect when gaseous amounts are equal on both sides.

equilibrium: A state with equal forward and reverse reaction rates
reversible reaction: A reaction that can proceed in both directions

Reactivity 3.1 · Proton transfer reactions

The volume delivered between two burette readings.
Calculate the known amount first, apply the stoichiometric ratio, then divide by the unknown solution volume in cubic decimetres. Use concordant titres as required by the school method and report the accepted values.
Rinse the burette with its solution and the pipette with the solution it transfers. Rinse the flask with distilled water. Add titrant slowly near the endpoint, swirl, and read the meniscus at eye level. Use a white tile and appropriate eye protection.

titre: The volume delivered between two burette readings
equivalence point: The point of stoichiometric reaction completion

Reactivity 3.2 · Electron transfer reactions

Loss of electrons.
Predict products using the specified electrolyte and electrode material. In an aqueous solution, hydrogen or oxygen may form because water-related species compete. Molten salts contain only the ions of the salt.
Use a low-voltage direct-current supply, approved electrodes, and the school risk assessment. Collect gases only by an approved method. Keep chlorine demonstrations teacher-controlled; do not ask students to generate hazardous gases independently.

oxidation: Loss of electrons
reduction: Gain of electrons

Reactivity 3.3 · Electron sharing reactions

An atom group determining characteristic reactions.
Distinguish addition, substitution, oxidation and polymerization by tracing bonds before and after reaction. Conditions and reagents belong to the reaction arrow; they are not interchangeable labels.
Draw displayed or structural formulae with the correct number of bonds at each carbon. Use a carbon count to check a proposed synthesis. At advanced level, track reagents and conditions through multistep routes.

functional group: An atom group determining characteristic reactions
isomer: A compound sharing a formula but differing in structure

Reactivity 3.4 · Electron-pair sharing reactions

An atom group determining characteristic reactions.
Distinguish addition, substitution, oxidation and polymerization by tracing bonds before and after reaction. Conditions and reagents belong to the reaction arrow; they are not interchangeable labels.
Draw displayed or structural formulae with the correct number of bonds at each carbon. Use a carbon count to check a proposed synthesis. At advanced level, track reagents and conditions through multistep routes.

functional group: An atom group determining characteristic reactions
isomer: A compound sharing a formula but differing in structure

Practical · Experimental programme

A quantified limitation on a measured result.
For a product or quotient, adding fractional uncertainties is a common maximum-uncertainty approximation. For a difference, add absolute uncertainties. A nonzero intercept can reveal an offset or an incomplete model.
Show units on axes and choose a sensible scale. Plot uncertainty bars where justified, draw a best-fit line rather than joining every point, and estimate steepest and shallowest plausible gradients when the course method calls for them.

uncertainty: A quantified limitation on a measured result
systematic error: A consistent measurement bias

Preparing for this qualification

Structure and reactivity replace the old topic/option model. Entropy and spontaneity is AHL; all other topics still require exact SL/AHL statement separation from the guide.
Paper 1A MCQ + 1B experimental/data work, Paper 2 short/extended responses; SL 1.5/1.5 h, HL 2/2.5 h; weights 36%/44%. Scientific investigation 20%, 3,000 words.
Practical work 40 h plus collaborative sciences project 10 h and investigation 10 h; use the current chemistry data booklet.

Teaching coverage still needed

Full 2025 SL/AHL understanding and guidance statements are not established by the brief. Focus cases do not cover complete bonding, acid-base, mechanism or spectroscopy objectives.
Full experimental-technique objectives and current data booklet need acquisition.