Edexcel A-Level Chemistry

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Foundation Chemistry (Topics 1-10, shared with AS)

Topic 1: Atomic Structure and the Periodic Table

1.1-1.4 - Atoms And Subatomic ParticlesCount the protons, neutrons and electrons in atoms, molecules and ions. Atomic and mass numbers describe the nucleus; ionic charge changes the electron count. A final charge check helps you catch the most common counting errors.
1.5-1.7 - Isotopes And Relative MassesIsotopes have the same proton number but different neutron numbers. Use the carbon-12 reference to distinguish relative isotopic mass from the weighted mean relative atomic mass, then calculate molecular and formula masses from chemical formulae.
1.8-1.10 - Mass Spectra And Relative MassRead the positions and relative heights of mass-spectrum peaks, calculate weighted mean masses and work backwards to isotope abundances. Combining isotope probabilities predicts the molecular-ion pattern of a diatomic molecule; a stated singly charged molecular ion gives its relative molecular mass.
1.11-1.14 - Ionisation EnergiesIonisation energy measures how strongly an atom or ion holds an electron. Define each removal precisely, then explain trends using nuclear charge, distance, shielding and the subshell occupied by the electron being removed.
1.15 - Evidence For Shells And SubshellsAtomic models must explain observations. Connect sharp emission lines to fixed energy gaps, large successive-ionisation jumps to shell boundaries, and irregular first-ionisation trends to subshells and paired electrons.
1.16-1.22 - Orbitals And Electronic ConfigurationsBuild electronic configurations from shells, subshells and orbitals. Use the filling and spin rules for atoms up to krypton, adjust the electron count for s- and p-block ions, and connect the configuration to periodic-table blocks.
1.23-1.26 - PeriodicityRepeating outer-electron configurations produce repeating chemical properties. Use data to connect atomic radius and ionisation energy to nuclear attraction, and melting and boiling temperatures to the structures and forces present in each element.

Topic 2: Bonding and Structure

2A.1-2A.6 - Ionic BondingUse ionic charge, radius and electron arrangements to explain the strength of a giant ionic lattice. Draw the ions formed by electron transfer, then use conductivity and directed migration as evidence for mobile charged particles.
2A.7-2A.9 - Covalent BondingA covalent bond holds atoms together through attraction between their nuclei and a shared electron pair. Count every outer electron in single, multiple and dative bonds, then relate bond length to strength for the same pair of elements.
2A.10-2A.12 - Shapes And Bond AnglesCount bonding regions and lone pairs to predict molecular shape and bond angles. Electron pairs repel, so their three-dimensional arrangement matters; the shape name describes the atom positions, while lone pairs help determine those positions.
2A.13-2A.15 - Electronegativity And PolarityElectronegativity predicts the direction of a bond dipole. Molecular shape determines whether the bond dipoles cancel, so a molecule can contain polar bonds while having no permanent dipole overall.
2A.16-2A.19 - Intermolecular Forces And Hydrogen BondingExplain the forces between molecules without confusing them with covalent bonds inside molecules. Use electron-cloud fluctuations, permanent dipoles and donor–acceptor requirements to predict attractions, including hydrogen bonds in pure substances and mixtures.
2A.20-2A.21 - Intermolecular Forces And SolventsConnect intermolecular forces to boiling temperature, volatility and solubility. Compare chain length, branching and hydrogen bonding, then explain solvent choice by the new attractions formed between solvent and solute.
2A.22-2B.23 - Metallic Bonding And Giant LatticesMetallic bonding explains how a solid can conduct and change shape. Compare its positive ions and delocalised electrons with ionic and giant covalent lattices, including the continuous silicon–oxygen network in silicon(IV) oxide.
2B.24-2B.25 - Simple Molecular Structures And Carbon AllotropesIdentify the units in a covalent solid: separate molecules or a continuous network. Compare iodine and ice with diamond, graphite and graphene, then read diagram keys to distinguish covalent bonds from intermolecular attractions.
2B.26-2B.27 - Structure And Physical PropertiesUse several observations together to deduce a substance’s structure, then predict its properties from the particles and attractions present. Apply the same reasoning to select a material that meets every stated requirement.

Topic 3: Redox I

3.1-3.2 - Oxidation NumbersOxidation numbers track electron ownership in compounds and ions. Learn to calculate them from a species’ total charge, recognise peroxides and metal hydrides, and distinguish an assigned oxidation number from a real ionic charge.
3.3-3.8 - Redox And DisproportionationUse electron transfer and oxidation-number changes to recognise redox reactions, identify oxidising and reducing agents, and explain disproportionation. Comparisons with neutralisation show why a visible chemical change is not always redox.
3.9-3.13 - Formulae And Redox EquationsUse Roman numerals to name oxidation states, balance charges to write formulae, and combine half-equations into full ionic equations. Each step conserves atoms and charge while making the transfer of electrons explicit.

Topic 4: Inorganic Chemistry and the Periodic Table

4A.1-4A.8 - Groups 1 And 2: Trends And ReactionsExplain Group 2 reactivity and the reactions of magnesium to barium, then compare hydroxide and sulfate solubility. Use ion size and polarisation to explain thermal stability, and electron transitions to explain flame colours and practical observations.
4B.9-4B.11 - Halogen Trends And DisplacementConnect halogen melting and boiling temperatures to intermolecular forces, and electronegativity and oxidising strength to atomic structure. Use displacement reactions and organic-layer colours to deduce which halogen forms.
4B.12-4B.14 - Halogen Reactions And Halide TestsTrack oxidation numbers through halogen reactions with metals, water and alkali. Compare hydrogen-halide reducing ability, identify halide ions with silver nitrate and ammonia, and use Group 7 trends to make justified predictions.
4C.15 - Inorganic Ion TestsIdentify carbonate, hydrogencarbonate, sulfate and ammonium ions using reagents, observations and balanced ionic equations. Plan fresh-portion tests and recognise what positive and negative results can establish.

Topic 5: Formulae, Equations and Amounts of Substance

5.1-5.5 - Moles, Formulae And Gas DataConnect particle counts, amount of substance and molar mass. Use composition, mass-change and gas measurements to calculate empirical and molecular formulae, with careful unit conversions and whole-number ratios.
5.6-5.10 - Equations And StoichiometryTurn balanced full and ionic equations into reacting amounts, masses and gas volumes. Core Practical 1 applies these relationships to measure the molar volume of a gas and evaluate collection errors.
5.11 - Concentrations And TitrationsCalculate solution concentrations and use titration data to find an unknown concentration. Prepare a standard acid for Core Practical 2, determine hydrochloric acid concentration in Core Practical 3, and connect indicator and apparatus choices to reliable results.
5.12-5.13 - Measurement Uncertainty And ErrorCalculate measurement uncertainty and percentage error, distinguish precision from accuracy, and follow each experimental fault through to its effect on the result. Use these ideas to improve practical methods and judge numerical evidence.
5.14-5.16 - Yield, Atom Economy And Practical EvidenceCompare percentage yield with atom economy, using balanced equations and experimental masses. Link test-tube observations to full and ionic equations, then choose precautions that address the risks of the actual procedure.

Topic 6: Organic Chemistry I

6A.1-6A.7 - Organic Formulae, Naming And IsomerismOrganic formulae communicate different information: atom ratios, connectivity or arrangement in space. This lesson shows how to translate between representations, name compounds, recognise reaction types and distinguish structural isomers from E/Z stereoisomers.
6B.8-6B.14 - Alkanes, Fuels And PollutionAlkane fuels connect molecular structure to everyday choices about energy and pollution. Learn how refineries separate and modify hydrocarbons, how combustion conditions determine pollutants, and how catalytic converters and renewable fuels address different problems.
6B.15-6B.17 - Radicals And Alkane SubstitutionLight can start a chain reaction in which halogens replace hydrogen atoms in alkanes. Follow the electrons through initiation, propagation and termination, then use the mechanism to explain why a synthesis produces a mixture.
6C.18-6C.23 - Alkenes And Addition ReactionsThe exposed electron density in an alkene double bond explains its addition reactions. Learn how sigma and pi bonds differ, then predict the products formed with hydrogen, halogens, hydrogen halides, steam and an oxidising agent.
6C.24 - Electrophilic Addition MechanismsCurly arrows track electron pairs as an alkene reacts with an electrophile. Work through halogen and hydrogen-halide addition, compare carbocation pathways, and transfer the same logic to an unfamiliar polar reagent.
6C.25-6C.29 - Alkene Tests And PolymersAn alkene double bond provides both a chemical test and a route to addition polymers. Learn to translate monomers into repeat units, then compare recycling, cracking, incineration and biodegradable materials using evidence across a product’s life cycle.
6D.30-6D.32 - Halogenoalkane ReactionsReplacing a halogen can make an alcohol, a nitrile or an amine; removing it together with a neighbouring hydrogen makes an alkene. Learn to classify the starting molecule and choose the reagent, solvent and attacking species for each route.
6D.33-6D.35 - Halogenoalkane Hydrolysis RatesA cloudy precipitate can reveal how quickly a halogenoalkane releases halide ions. In Core Practical 4, use controlled conditions and timing data to distinguish carbon-structure effects from the carbon–halogen bond-strength trend.
6D.36 - Nucleophilic Substitution MechanismsA nucleophile replaces a halogen by donating an electron pair to carbon as the carbon–halogen bond breaks. Compare hydroxide and ammonia: both substitute at a primary carbon, but ammonia first forms a charged organic ion that must lose a proton.
6E.37-6E.38 - Alcohol Classification And ReactionsThe carbon bearing the OH group determines an alcohol’s class and its oxidation products. Learn how reagents select combustion, substitution, oxidation or dehydration, and use structural formulae to predict and balance each change.
6E.39 - Organic Preparation And PurificationMaking a liquid organic compound requires both a reaction and a separation strategy. Use volatility, solubility, density and boiling range to choose and explain reflux, extraction, drying and distillation in the oxidation of ethanol and preparation of a chloroalkane.

Topic 8: Energetics I

8.1-8.4 - Enthalpy ChangesEnthalpy changes describe heat transferred at constant pressure. Connect temperature observations to the correct sign and energy levels, then use standard conditions and precise definitions to describe reaction, formation, combustion and neutralisation.
8.5-8.6 - CalorimetryA measured temperature change can reveal the energy transferred by a reaction. Calculate molar enthalpy changes from cup and combustion experiments, correct for cooling and explain how practical assumptions affect the result.
8.7-8.8 - Hess's LawHess’s law connects measurable reactions to an enthalpy change that is difficult to measure directly. Build cycles from chemical equations, preserve signs and amounts, and apply the method to Core Practical 8 calorimetry.
8.9-8.11 - Bond EnthalpiesBond breaking takes in energy and bond formation releases it. Use gas-phase bond enthalpies to estimate reaction enthalpies, find an unknown bond enthalpy and explain why mean values give approximate results.

Advanced Chemistry (Topics 11-19)

Topic 12: Acid-base Equilibria

12.1-12.6 - Acids, Bases And pHFollow proton transfer to identify acids, bases and conjugate pairs. Use the logarithmic pH scale to calculate hydrogen ion concentrations and compare solutions quantitatively.
12.7-12.10 - Weak Acids, Ka And pHDistinguish acid strength from concentration, then choose a calculation route for strong or weak monobasic acids. Check the assumptions behind the square-root approximation before trusting its result.
12.11-12.13 - Kw, pKa And Strong-Base pHWater links hydrogen and hydroxide ion concentrations through its ionic product. Use that link to calculate strong-base pH, account for hydroxide stoichiometry and interpret pKa and pKw.
12.14-12.15 - pH Experiments And KaUse pH measurements to compare acids, bases and salts and follow the effects of dilution. Prepare a known weak-acid concentration and combine mass, volume and measured pH to determine its dissociation constant.
12.16-12.17 - Titration Curves And IndicatorsRead and sketch titration curves for strong and weak acids and bases. Connect each equivalence region to the ions present, then choose an indicator whose transition range gives a precise endpoint.
12.18-12.24 - Buffers And NeutralisationBuffers contain acid and base reserves that remove small additions of either reagent. Calculate their pH after reaction, design a mixture, use half-neutralisation data and explain neutralisation energies and the blood buffer.

Topic 13: Energetics II

13A.1-13A.3 - Lattice Energy And Born–Haber CyclesBuild an enthalpy route from elements to an ionic solid. Learn why gaseous particles, electron transfers and formula coefficients determine the signs and terms in a Born–Haber cycle.
13A.4-13A.8 - Ionic Bond Strength And PolarisationUse lattice energies to compare ionic attraction and test the purely ionic model. Explain differences between predicted and experimental values through distortion of anion electron clouds.
13A.9-13A.11 - Solution And Hydration EnthalpyExplain the temperature change when an ionic solid dissolves. Use lattice and hydration enthalpies to construct Hess cycles, calculate missing values and compare the effects of ionic charge and radius.
13B.12-13B.17 - Entropy And FeasibilityExplain how endothermic changes can occur and why an exothermic reaction can make its reacting particles more ordered. Calculate entropy changes for the system and surroundings, then combine them to judge the direction of change.
13B.18-13B.22 - Gibbs Energy And FeasibilityCombine enthalpy, entropy and temperature to predict thermodynamic feasibility. Calculate a temperature boundary and an equilibrium constant, then distinguish a favourable equilibrium from a reaction that is fast enough to observe.

Topic 14: Redox II

14.1-14.5 - Standard Electrode PotentialsTrack redox using electrons and oxidation numbers across the periodic table. Learn what a standard electrode potential compares and how the standard hydrogen electrode provides a reproducible reference.
14.6-14.9 - Electrochemical CellsBuild and investigate electrochemical cells, calculate their standard emf and write cell diagrams. Connect each apparatus choice and controlled condition to the reliability of the voltage measurement.
14.10-14.14 - Redox Feasibility And DisproportionationUse reduction potentials to predict redox direction and disproportionation. Link the cell emf to entropy and equilibrium, while distinguishing standard predictions from real reaction conditions and rate.
14.15-14.17 - Storage And Fuel CellsExplain how rechargeable cells store energy and fuel cells convert a continuing fuel supply into electrical work. Balance acidic and alkaline hydrogen–oxygen half-equations and compare devices for a stated use.
14.18-14.19 - Redox TitrationsUse electron-balanced equations to connect redox endpoints with reacting amounts. Practise iron–manganate(VII), iodine–thiosulfate, dilution and back-titration calculations alongside reliable practical methods.

Topic 15: Transition Metals

15A.1-15A.3 - d-Block Configurations And Transition MetalsDeduce period-4 d-block atom and ion configurations, including chromium and copper. Use stable-ion configurations to identify transition metals and explain their variable oxidation numbers.
15A.4-15A.10 - Ligands, Complex Ions And ColourConnect ligand bonding and complex-ion charge to the absorption of visible light. Use d-electron configurations to explain colour, while recognising the limits of the simple d-orbital model.
15A.11-15A.19 - Complex Shapes, Isomerism And HaemoglobinCount donor atoms to predict coordination number and complex shape. Explore square-planar isomerism, chelating ligands and the ligand exchange that interferes with oxygen transport in haemoglobin.
15B.20-15B.23 - Vanadium And Chromium RedoxFollow vanadium and chromium through oxidation states using colour, balanced half-equations and electrode potentials. Distinguish redox changes from the chromate–dichromate acid–base equilibrium.
15B.24-15B.28 - Transition Metal Reactions And ComplexesUse reagent amount and colour changes to identify transition-metal ions. Write the equations for precipitation, amphoteric dissolving and ligand exchange, then explain chelate stability through entropy.
15B.29-15B.32 - Heterogeneous CatalysisExplain how a solid catalyst supplies a faster surface pathway. Apply adsorption, reaction and desorption to the Contact process and the removal of harmful exhaust gases.
15B.33-15B.35 - Homogeneous Catalysis And Complex PreparationTrack catalysts and intermediates through aqueous redox cycles, including autocatalysis. Prepare and purify a copper complex, and use its stoichiometry to calculate and evaluate the isolated yield.

Topic 16: Kinetics II

16.1-16.2 - Rates And Rate EquationsRead rate equations as experimental evidence. Deduce orders from controlled comparisons, calculate rates and rate constants, and distinguish kinetic quantities from stoichiometry and yield.
16.3-16.4 - Measuring Reaction RatesChoose a measurable change that follows reaction progress. Compare initial-rate experiments with continuous monitoring, then plan measurements whose controls, resolution and chemical selectivity make the resulting data useful.
16.5-16.7 - Rate Graphs And Reaction OrdersUse graph gradients, half-lives and initial-rate ratios to determine reaction orders. Keep the axes, units and controlled variables visible so each conclusion follows from the data.
16.8-16.11 - Rate-Determining Steps And MechanismsUse the acid-catalysed iodination of propanone and halogenoalkane hydrolysis to connect rate equations with possible mechanisms. Check both rate-controlling steps and overall stoichiometry, and distinguish supporting evidence from unique proof.
16.12 - Activation Energy From GraphsTransform rate constants or clock times into a straight-line graph against reciprocal absolute temperature. Use the gradient to calculate activation energy, with the correct sign, units and experimental assumptions.

Topic 17: Organic Chemistry II

17A.1-17A.5 - Chirality And Optical IsomerismA flat formula can hide two different three-dimensional molecules. Learn to recognise a chiral centre, draw its mirror-image pair and use optical rotation together with reaction-rate evidence to distinguish substitution pathways.
17B.6-17B.8 - Carbonyl Compounds And ReactionsThe polar carbonyl bond explains how aldehydes and ketones dissolve, react and can be identified. Follow oxidation, reduction and cyanide addition from the structure to the product, then combine chemical tests to identify an unknown.
17C.9-17C.13 - Carboxylic Acids And Their DerivativesThe carboxyl group connects acidity, oxidation and the synthesis of esters and acyl chlorides. Learn to track its carbon atom through each reaction and explain physical properties using intermolecular hydrogen bonds.
17C.14-17C.16 - Acyl Chlorides, Esters And PolyestersAcyl chlorides transfer an acyl group to oxygen or nitrogen nucleophiles. Trace the resulting ester and amide links, compare acidic and alkaline ester hydrolysis, and construct polyester repeat units from their monomers.

Topic 18: Organic Chemistry III

18A.1-18A.3 - Benzene Models And EvidenceBenzene’s equal bond lengths and unexpectedly small heat release on hydrogenation challenge a literal alternating-bond model. Use orbital overlap and measured data to explain delocalisation, extra stability and resistance to bromine addition.
18A.4-18A.7 - Benzene And Phenol ReactionsBenzene reacts by replacing a ring hydrogen while recovering its delocalised π system. Learn how catalysts generate electrophiles, draw the substitution mechanism and explain why phenol brominates much more readily.
18B.8-18B.13 - Amines, Amides And Amino AcidsThe nitrogen lone pair explains why amines can accept protons, attack carbon and bind metal ions. Use that idea to compare basicity, identify amine and amide groups and choose practical routes to primary amines.
18B.14-18B.17 - Condensation Polymers And Amino AcidsBuild condensation-polymer repeat units, follow amino acids as their charge changes with pH and identify the peptide links broken during protein hydrolysis. Then plan the linked observations and deductions needed to analyse inorganic and organic unknowns in Core Practical 15.
18C.18-18C.21 - Organic Synthesis And Chain ExtensionCombine composition, chemical tests and spectra to deduce a target, then plan a route of up to four steps. Grignard reactions provide a controlled way to make new carbon–carbon bonds, provided reagents and work-up are used in the right order.
18C.22 - Organic Purification And Aspirin PreparationA successful preparation produces a dry, purified substance with convincing evidence of identity and purity. Use aspirin preparation in Core Practical 16 to connect reaction, crystallisation and yield, then compare the apparatus used to purify solids and liquids.

Topic 19: Modern Analytical Techniques II

19A.1 - High-Resolution Mass SpectrometryWhole-number molecular masses can hide different molecular formulae. Calculate accurate masses using the supplied isotope values, distinguish candidate formulae and explain why even an exact molecular mass cannot identify every structural isomer.
19B.2-19B.5 - Carbon And Proton NMRNMR reveals how atoms are grouped into chemical environments. Use carbon signals, proton chemical shifts, integration and splitting together to distinguish isomers and predict the spectra of a known structure.
19C.6-19C.8 - Chromatography And Mass SpectrometryChromatography separates mixture components because they spend different proportions of time in mobile and stationary phases. Read a chromatogram, calculate Rf, interpret retention times and decide how mass spectra strengthen an identification.