OCR A Level Chemistry B Paper 3 2025 Question Paper

Get the official OCR A-Level Chemistry B (Salters) H433/03 Practical Skills in Chemistry June 2025 question paper used in the Summer 2025 OCR examination series. This authentic examiner-issued PDF contains practical-skills, equilibrium, energetics, spectroscopy, polymers, electrochemistry, analytical, and inorganic-chemistry questions exactly as presented to candidates during the live OCR assessment.

This paper includes exam questions on Group 2 carbonates and thermal stability, photon-energy calculations using Planck’s equation, Ksp calculations for barium sulfate, nylon polymerisation using sebacoyl chloride, addition and condensation polymerisation, aromatic-ring delocalisation in styrene, nitration and reduction of benzoic acid derivatives, entropy and feasibility of methane steam reforming, methanol equilibrium calculations using Kc, industrial catalyst processes, oxidation-state balancing for periodate and manganese ions, colorimetry practical techniques, and percentage-by-mass calculations for manganese in paperclips. Candidates are required to complete thermodynamic calculations, write ionic equations, analyse equilibrium systems, explain industrial chemistry processes, interpret polymer structures, and describe accurate laboratory methods involving volumetric apparatus and colorimeters. Pair it with the matching OCR H433/03 June 2025 mark scheme on markscheme.net for complete examiner-style revision and practical-skills 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 B (Salters) students preparing for the 2026 examination series, Year 13 learners studying Practical Skills in Chemistry, retake students targeting A/A* grades, and home-schooled candidates seeking authentic OCR exam practice under timed conditions.

It is also ideal for teachers, private tutors, revision-course providers, and parents supporting Chemistry revision at home. The question paper can be used for mock examinations, equilibrium-calculation practice, polymerisation revision, practical-skills assessment, colorimetry analysis, and OCR exam-technique development.