ChemistryQ&A by dot point

Quantum numbers and the shapes of s, p and d atomic orbitals; the aufbau principle, Pauli exclusion principle and Hund's rule used to write electronic configurations; and how electronic structure explains the s, p and d blocks and periodic trends in ionisation energy.

The equilibrium constant K and its expression, Le Chatelier's principle, the dissociation of weak acids in terms of Ka and pKa, the calculation of pH for weak acids, the action of buffer solutions, and the selection of indicators for titrations.

The wave-particle nature of electromagnetic radiation, the relationships E = hf and c = f lambda, and how line emission and absorption spectra provide evidence for quantised electronic energy levels in atoms.

Rate equations of the form rate = k[A]^m[B]^n, the order of reaction with respect to each reactant and overall, the rate constant and its units, and the link between the rate equation, the rate-determining step and a reaction mechanism.

Standard enthalpy and entropy changes, the second law of thermodynamics, and the Gibbs free energy relationship delta G = delta H - T delta S used to decide reaction feasibility, find the temperature of feasibility, and interpret Ellingham diagrams.

Transition metals as d-block elements with variable oxidation states; ligands and complexes with coordinate bonds, coordination number and shape; the origin of colour in d-d transitions and the splitting of d orbitals; and the catalytic properties of transition metals.

Elemental microanalysis to find the empirical formula, mass spectrometry to find the molecular mass and fragmentation pattern, infrared spectroscopy to identify functional groups, and proton and carbon-13 nuclear magnetic resonance spectroscopy to map the carbon-hydrogen framework.

The formation of molecular orbitals from atomic orbitals, sigma and pi bonds, sp, sp2 and sp3 hybridisation and the shapes they give, and how conjugation and chromophores lead to the absorption of visible light and colour in organic molecules.

Drugs as molecules that bind to receptors or enzymes, the action of agonists and antagonists, the role of functional groups in binding, structure-activity relationships, and how these ideas guide the design of medicines.

Geometric (cis-trans, E/Z) isomerism arising from restricted rotation about a double bond, optical isomerism arising from chirality, enantiomers and optical activity measured by polarimetry, racemic mixtures, and the importance of stereochemistry in pharmaceuticals.

The reactions of the main functional groups including nucleophilic substitution, elimination, oxidation, reduction, condensation and hydrolysis, the use of these reactions to design multi-step synthetic routes, and the assessment of a route by percentage yield, atom economy and hazards.

Common chemical apparatus and the laboratory techniques used to prepare, purify and analyse substances, including titration, distillation, reflux, vacuum filtration, recrystallisation, thin-layer chromatography, colorimetry and melting-point determination.

The practical skills of scientific inquiry assessed by the project: planning a valid investigation, generating reliable raw data, processing and presenting results, analysing data with uncertainties, evaluating the procedure, and reporting with referencing.

Stoichiometric calculations from balanced equations, gravimetric analysis from measured masses, volumetric analysis including acid-base, redox, complexometric and back titrations, and the calculation of percentage yield and atom economy.