The OCR GCSE Chemistry (Gateway Science) Higher Tier Paper 3 from June 2023 evaluates core and advanced chemical concepts, including atomic structure, bonding, stoichiometry, and reaction rates. Key topics covered include electrolysis, fractional distillation, environmental chemistry, and thermodynamics. Practical applications such as titration, chromatography, and purification techniques are integrated. The paper emphasizes data interpretation, experimental design, and the environmental impact of industrial processes, focusing on sustainability and efficiency. Students are assessed on their problem-solving, analytical, and scientific reasoning skills, with attention to chemical calculations and reaction mechanisms.