Chemistry — A2 Level Chemistry

Lattice energy and Born–Haber cycles, enthalpies of solution and hydration, entropy, and Gibbs free energy — the thermodynamic core of Paper 4.

Electrolysis and predicting its products, Faraday-constant calculations, standard electrode potentials and cells, feasibility from E⦵cell, the Nernst equation, and ΔG⦵ = −nE⦵cellF.

Ionic equilibria: Ka and Kw, buffers, solubility product and partition coefficients.

Rate equations and orders, half-lives, mechanisms and the rate-determining step, and catalysis.

The A2 explanations behind Group 2 trends: anion polarisation and thermal stability, and the lattice-vs-hydration solubility argument.

Complexes, ligand exchange, redox chemistry, colour from d-orbital splitting, and the shapes and stability of complexes.

New A2 functional groups, aromatic naming, optical isomerism, and the two new mechanism families.

Arenes: electrophilic substitution on benzene, directing effects, and side-chain reactions.

Halogenoarenes, and why the C–Cl bond in chlorobenzene refuses the reactions chloroalkanes undergo.

Phenol's acidity and reactions, ester formation with acyl chlorides, and diazonium coupling.

Acyl chlorides, the addition–elimination mechanism, and relative acidities across the series.

Amines and their basicity, phenylamine and azo dyes, amides, and amino acids as zwitterions.

Condensation polymers — polyesters and polyamides — and the chemistry of degradable plastics.

Multi-step routes at A Level: choosing reagents and conditions across the full functional-group map, including aromatics.

Chromatography and NMR: Rf values, carbon-13 and proton NMR, and the TMS/D2O conventions.