Pearson Edexcel · International GCSE

Recent past papers

18 paper and mark-scheme pairs

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 · IGCSE Chemistry (12)

Exercise sheets · IGCSE Chemistry (49)

Presentation slides · IGCSE Chemistry (12)

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 →

1 · Principles of chemistry

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.
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.
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.

ionic bond: Attraction between oppositely charged ions
delocalized electron: An electron not confined to one atom or bond
mole: The SI unit of amount of substance
limiting reagent: The reactant that limits the possible product amount
oxidation: Loss of electrons
reduction: Gain of electrons

2 · Inorganic chemistry

Separation using two phases.
Rf is distance travelled by a component divided by distance travelled by the solvent front, both measured from the baseline. Compare under the same conditions; an Rf value alone does not establish identity across different solvents.
Use pencil for the baseline, keep spots above solvent level, mark the solvent front promptly, and run known references alongside unknowns. For ion tests, use clean equipment and separate aliquots to avoid carrying reagents into later tests.

chromatography: Separation using two phases
Rf: Spot distance divided by solvent-front distance

3 · Physical chemistry

Transferring energy to the surroundings.
Calculate energy transferred from the mass, specific heat capacity and temperature rise when these are given. At GCSE, use reaction profiles and bond-energy differences where your tier specifies them; this lesson does not introduce advanced molar enthalpy calculations.
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.
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.
A state with equal forward and reverse reaction rates.
Changing conditions can change the equilibrium composition. A catalyst speeds both directions and shortens the time to equilibrium; it does not change the final equilibrium composition at a fixed temperature.
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.

exothermic: Transferring energy to the surroundings
enthalpy change: Heat change at constant pressure for a stated process
activation energy: The energy barrier for a reaction pathway
rate: Change in a measured quantity per unit time
equilibrium: A state with equal forward and reverse reaction rates
reversible reaction: A reaction that can proceed in both directions

4 · Organic chemistry

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

Preparing for this qualification

This is linear 4CH1, with C-suffixed separate-Chemistry statements retained.
Paper 1C: 110 marks, 2 h, 61.1%; Paper 2C: 70 marks, 1 h 15 min, 38.9%; no tiers.
Use specification practical statements, not the UK GCSE core-practical list.

Teaching coverage still needed

Complete atomic/periodic/separation/structure statements including C extensions remain.
Groups, gases, reactivity/extraction, acids/salts and all analytical tests remain.
Use IGCSE variants; energy profiles, bond-energy calculations and every C equilibrium/energetics statement remain.
Full fuels, alkanes/alkenes, alcohols/acids/esters and polymers including C extensions remain.