England · OCRSyllabus
Chemistry syllabus, dot point by dot point
Every dot point in the England Chemistrysyllabus, with a focused answer for each one. Click any dot point for a worked explainer, past exam questions, and links to related dot points. Written by Claude Opus 4.8, Anthropic's latest AI.
Module 2: Foundations in chemistry (2.1.4 Acids)
Module overview →- How do acids, bases and salts behave, and how do we prepare and standardise solutions?Acids as proton donors, strong and weak acids, bases, alkalis and neutralisation, the reactions of acids with metals, carbonates and bases, salt preparation, and the techniques of standard solutions and acid-base titration.9 min answer →
- How does the mole let us count particles and predict the masses, volumes and concentrations in a reaction?The Avogadro constant and the mole, molar mass, the ideal gas equation, empirical and molecular formulae, concentration and titration calculations, and percentage yield and atom economy.11 min answer →
- How does the arrangement of sub-atomic particles and isotopes explain atomic mass and chemical identity?Sub-atomic particles and their relative masses and charges, atomic number and mass number, isotopes and their identical chemical properties, and the determination of relative atomic mass from mass spectra.9 min answer →
- How do we represent chemical species and reactions with formulae and balanced equations?Names and formulae of common ions, binary and polyatomic compounds, the use of oxidation numbers in naming, and the construction of balanced full and ionic equations including state symbols.9 min answer →
- How does electron configuration explain bonding, molecular shape and the properties of materials?Electron configuration in shells, sub-shells and orbitals, ionic, covalent (including dative) and metallic bonding, electronegativity and bond polarity, electron-pair repulsion and molecular shapes, and the properties of the four crystal structures.11 min answer →
- How do oxidation numbers let us track electron transfer in chemical reactions?Oxidation numbers and the rules for assigning them, oxidation and reduction as loss and gain of electrons, oxidising and reducing agents, and the construction of half-equations and overall redox equations.9 min answer →
Module 3: Periodic table and energy (3.2.3 Chemical equilibrium)
Module overview →- How does a reversible reaction reach equilibrium, and how does it respond to changing conditions?Dynamic equilibrium, Le Chatelier's principle and the effect of concentration, pressure and temperature, the role of a catalyst, the equilibrium constant Kc for homogeneous equilibria, and the compromise conditions used in industry.11 min answer →
- How do we measure and calculate the energy released or absorbed in a chemical reaction?Enthalpy and standard enthalpy changes, exothermic and endothermic reactions, calorimetry and the q = mcDeltaT equation, average bond enthalpies, and Hess's law including formation and combustion cycles.12 min answer →
- How do the trends in reactivity of Group 2 metals and the halogens follow from their electron structures?Group 2 reactivity and reducing power, reactions of Group 2 elements and their oxides and hydroxides, the halogens as oxidising agents, halide displacement, disproportionation of chlorine, and tests for halide ions.11 min answer →
- How do the structure of the periodic table and the periodic trends in properties follow from electron configuration?The periodic table arranged by atomic number into periods and groups, the s, p and d blocks, and the periodic trends in atomic radius, first ionisation energy and melting point across Periods 2 and 3.11 min answer →
- How can simple test-tube reactions identify the ions present in an unknown sample?Qualitative tests for carbonate, sulfate, halide and ammonium ions, the correct sequence of tests to avoid interference, and the observations and ionic equations for each test.10 min answer →
- What controls how fast a reaction goes, and how does a catalyst speed it up?Collision theory, the effect of concentration, pressure, surface area and temperature on rate, the Boltzmann distribution and activation energy, and the action of catalysts including the difference between homogeneous and heterogeneous catalysis.11 min answer →
Module 4: Core organic chemistry (4.2.1 Alcohols)
Module overview →- How do primary, secondary and tertiary alcohols differ in their reactions?Classification and properties of alcohols (hydrogen bonding), combustion, oxidation by acidified dichromate (primary to aldehyde and carboxylic acid, secondary to ketone, tertiary not oxidised), dehydration to alkenes, and substitution to haloalkanes.11 min answer →
- Why are alkanes unreactive, and how do they burn and react with halogens?Structure and bonding of alkanes (sigma bonds, tetrahedral carbon), boiling-point trends, complete and incomplete combustion, pollutants, and free-radical substitution with halogens (initiation, propagation, termination).11 min answer →
- Why is the carbon-carbon double bond so reactive, and what does it react with?Structure and bonding of alkenes (sigma and pi bonds, trigonal planar carbon), E/Z isomerism, electrophilic addition (hydrogen, halogens, hydrogen halides and steam), Markownikoff's rule, and addition polymerisation.12 min answer →
- How do we name organic compounds and represent the different ways their atoms can be arranged?Formulae (empirical, molecular, general, structural, displayed and skeletal), homologous series and functional groups, IUPAC nomenclature, and isomerism (structural and E/Z stereoisomerism with Cahn-Ingold-Prelog priority).11 min answer →
- Why do haloalkanes react with nucleophiles, and how does the carbon-halogen bond control the rate?Polarity of the carbon-halogen bond, nucleophilic substitution (with hydroxide, cyanide and ammonia), the trend in hydrolysis rate with carbon-halogen bond enthalpy, elimination to alkenes, and the role of CFCs in ozone depletion.12 min answer →
- How do we plan a route to a target molecule, and how do infrared and mass spectra reveal structure?Planning multi-step synthesis routes between functional groups using practical techniques (reflux, distillation, purification), and the analytical techniques of infrared spectroscopy (functional-group absorptions) and mass spectrometry (molecular ion and fragmentation).12 min answer →
Module 5: Physical chemistry and transition elements (5.1.3 Acids, bases and buffers)
Module overview →- How do we calculate the pH of acids, bases and buffers, and why do buffers resist change?The Bronsted-Lowry model and conjugate pairs, pH and the ionic product of water Kw, the acid dissociation constant Ka and pKa for weak acids, buffer action and pH, titration curves, and indicator choice.13 min answer →
- Why do some endothermic reactions still happen, and how do we predict feasibility?Entropy as a measure of disorder, calculating entropy change of reaction, and the Gibbs free energy equation to decide feasibility and find the temperature at which a reaction becomes feasible.12 min answer →
- How do we quantify the position of equilibrium, and what changes its value?The equilibrium constant Kc in terms of concentrations and Kp in terms of partial pressures and mole fractions, calculations from equilibrium amounts, and the effect of temperature and catalysts on the constant.12 min answer →
- How do we find the lattice enthalpy of an ionic solid, and what makes it large?Lattice enthalpy and its determination by Born-Haber cycles, the enthalpy changes involved (formation, atomisation, ionisation, electron affinity), enthalpies of solution and hydration, and the effect of ionic charge and radius.13 min answer →
- How do we find the rate equation of a reaction, and what does it tell us about the mechanism?Orders of reaction and the rate equation, the rate constant and its units, concentration-time and rate-concentration graphs, half-life, the rate-determining step, and the Arrhenius equation.12 min answer →
- How do standard electrode potentials let us predict which redox reactions happen?Redox half-equations, standard electrode potentials measured against the standard hydrogen electrode, cell notation and standard cell potential, predicting feasibility, and storage and fuel cells.13 min answer →
- What gives the transition metals their colours, complexes and catalytic power?Definition and electron configurations of transition elements (including the chromium and copper exceptions), complex ions, ligands and shapes, ligand substitution with colour changes, precipitation reactions, the origin of colour, and catalysis.13 min answer →
Module 6: Organic chemistry and analysis (6.1.1 Aromatic compounds)
Module overview →- Why is benzene so stable, and how does it react by substitution?The delocalised model of benzene and the evidence for it, the stability of the ring, and the electrophilic substitution reactions of benzene (nitration, halogenation and Friedel-Crafts acylation).12 min answer →
- How do we distinguish aldehydes from ketones, and what reactions does the carbonyl group undergo?Aldehydes and ketones, oxidation of aldehydes, reduction with sodium tetrahydridoborate, nucleophilic addition of hydrogen cyanide, and the tests for carbonyl compounds (2,4-DNPH, Tollens' reagent and Fehling's solution).12 min answer →
- How do carboxylic acids behave as acids, and how are esters and acyl derivatives made and broken?Acidity of carboxylic acids and their reactions with metals, alkalis and carbonates; esterification and ester hydrolysis (acid and alkaline); and the reactions of acyl chlorides and acid anhydrides.12 min answer →
- How do chromatography and NMR spectroscopy let us separate mixtures and determine structures?Chromatography (thin-layer with Rf values and gas chromatography with retention times), carbon-13 and proton NMR spectroscopy (chemical shift, integration and the n+1 splitting rule with TMS reference), and combining analytical techniques to identify structures.13 min answer →
- How do amines act as bases, what is a chiral centre, and how do condensation polymers form?Amines and their basicity and preparation, amino acids and the amide link, optical isomerism and chirality, condensation polymers (polyesters and polyamides), carbon-carbon bond formation using nitriles, and multi-step organic synthesis.13 min answer →