Blog

A topic-by-topic revision guide for OCR A-Level Chemistry A (H432) atoms and moles — relative masses, mass spectrometry, the mole and Avogadro, ideal gas, empirical and molecular formulae, percentage yield and atom economy.

A topic-by-topic revision guide for OCR A-Level Chemistry A (H432) basic organic and hydrocarbons — functional groups, nomenclature, isomerism, mechanism vocabulary, alkanes free-radical substitution, alkenes electrophilic addition, E/Z stereoisomerism and addition polymerisation.

A topic-by-topic revision guide for OCR A-Level Chemistry A (H432) carbonyls, nitrogen chemistry, polymers and spectroscopy — aldehydes, ketones, carboxylic acids, esters, acyl chlorides, amines, amino acids, condensation polymers, chromatography, NMR and combined techniques.

A topic-by-topic revision guide for OCR A-Level Chemistry A (H432) energetics and electrochemistry — lattice enthalpy, Born-Haber cycles, hydration and solution enthalpy, entropy, Gibbs free energy, standard electrode potentials, electrochemical cells and redox titrations.

A topic-by-topic revision guide for OCR A-Level Chemistry A (H432) enthalpy, rates and equilibrium — standard enthalpy changes, calorimetry, Hess's law, mean bond enthalpy, collision theory, Boltzmann distributions, catalysts, dynamic equilibrium, Le Chatelier and Kc.

A topic-by-topic revision guide for OCR A-Level Chemistry A (H432) periodicity, Group 2 and halogens — periodic trends, ionisation energies, Period 3 structure, Group 2 reactivity, halogen oxidising trends, halide reducing tests, qualitative anion analysis.

A topic-by-topic revision guide for OCR A-Level Chemistry A (H432) quantitative rates and equilibrium — rate equations, orders of reaction, half-life, initial-rates, Arrhenius, Kp and partial-pressure equilibria.

A topic-by-topic revision guide for OCR A-Level Chemistry A (H432) transition elements and aromatic chemistry — d-block electron configurations, ligands and complex ions, ligand substitution, cisplatin and haemoglobin, qualitative tests, colorimetry, benzene electrophilic substitution and phenols.

A topic-by-topic revision guide for OCR A-Level Biology A (H420) biodiversity, classification and evolution — biodiversity levels, sampling techniques, Simpson's Index, genetic diversity, conservation, classification, three-domain phylogeny, evidence for evolution, natural selection, speciation, Hardy-Weinberg and chi-squared analysis.

A topic-by-topic revision guide for OCR A-Level Biology A (H420) biological molecules — water, monosaccharides, disaccharides, polysaccharides, lipids, amino acids, protein structure, inorganic ions and biochemical tests.

A topic-by-topic revision guide for OCR A-Level Biology A (H420) cell structure — light/TEM/SEM/confocal microscopy, magnification and resolution, slide preparation, eukaryotic ultrastructure, the cytoskeleton, protein production and prokaryotic cells.

A topic-by-topic revision guide for OCR A-Level Biology A (H420) genome manipulation, cloning, biotechnology and ecology — DNA profiling and sequencing, genetic engineering, GMOs, gene therapy, plant and animal cloning, microorganisms in biotechnology, immobilised enzymes, ecosystems and biomass transfer, nutrient cycles and succession, and populations, sustainability and conservation.