OCR A Level Chemistry A Paper 2 2025 Mark Scheme

Get the official OCR A-Level Chemistry A H432/02 Synthesis and Analytical Techniques mark scheme from the June 2025 examination series. This examiner-approved PDF contains the exact mark allocations, mechanism guidance, spectroscopy interpretations, level-of-response descriptors, examiner annotations, calculation methods, and assessment-objective breakdowns used during live Summer 2025 OCR marking.

This mark scheme provides detailed examiner guidance for questions covering E/Z stereoisomerism, incomplete combustion of hydrocarbons, electrophilic substitution, nitration of aromatic compounds, polymerisation reactions, biodegradable polymers, nucleophilic substitution mechanisms, bromination of phenol, amino-acid TLC analysis, β-keto acid decomposition, NaBH4 reduction mechanisms, infrared spectroscopy, proton and carbon-13 NMR interpretation, mass-spectrum fragmentation, and structural determination of unknown organic compounds. It includes accepted alternative answers, error-carried-forward guidance, curly-arrow marking rules, annotation conventions, significant-figure tolerances, level-of-response criteria, and OCR examiner principles used in the live 2025 series. Pair it with the matching OCR H432/02 June 2025 question paper on markscheme.net for complete examiner-style revision and exam preparation. Updated for the 2025/2026 academic year, mobile-friendly, and instantly downloadable from markscheme.net.

This document is designed for OCR A-Level Chemistry A students preparing for the 2026 examination series, Year 13 learners studying Synthesis and Analytical Techniques, retake students targeting A/A* grades, and home-schooled candidates seeking examiner-level insight into OCR marking expectations.

It is also essential for teachers, private tutors, revision-course providers, and parents supporting Chemistry revision at home. The mark scheme can be used for mock-exam grading, mechanism checking, spectroscopy-answer verification, chromatography analysis, structural-determination practice, and identifying weaknesses in OCR Chemistry exam technique.