OCR A-Level Chemistry A Past Papers & Mark Schemes

OCR A-Level Chemistry A (H432) examines its content through three papers that progressively integrate physical, inorganic, and organic chemistry. The specification organises content into six modules, but the papers cut across these modules in ways that encourage synoptic thinking rather than compartmentalised revision. Paper 1: Periodic Table, Elements and Physical Chemistry (H432/01, 2 hours 15 minutes, 100 marks, 37%) focuses on physical chemistry and inorganic chemistry drawn from Modules 2, 3, and 5. Physical chemistry content includes atomic structure and isotopes, bonding and intermolecular forces, energetics (enthalpy, entropy, and free energy), chemical equilibrium (Kc, Kp, Le Chatelier's principle), acid-base chemistry (pH calculations, buffers, titration curves), and electrochemistry (electrode potentials, electrochemical cells). Inorganic content covers periodicity, Group 2 and Group 7 chemistry, and transition metal chemistry (complex ions, ligand substitution, redox titrations). Paper 2: Synthesis and Analytical Techniques (H432/02, 2 hours 15 minutes, 100 marks, 37%) draws from Modules 2, 4, and 6, emphasising organic chemistry and analytical methods. Content includes naming and functional groups, reaction mechanisms (nucleophilic substitution, electrophilic addition, elimination), carbonyl chemistry (aldehydes, ketones, carboxylic acids, esters, acylation), aromatic chemistry (electrophilic substitution), nitrogen chemistry (amines, amino acids, polymers), and analytical techniques — mass spectrometry, infrared spectroscopy, NMR spectroscopy (both ¹H and ¹³C), and chromatography. Paper 3: Unified Chemistry (H432/03, 1 hour 30 minutes, 70 marks, 26%) is synoptic, drawing on all six modules. It always includes a passage-based question requiring interpretation of unfamiliar chemical information, questions on experimental design and data analysis, and extended-response questions that integrate physical, inorganic, and organic chemistry.