Cambridge Chemistry 0620 Paper 4 Revision Guide for May/June 2026

Cambridge’s Chemistry 0620 Paper 4 is a 1‑hour‑15‑minute, 80‑mark extended theory paper. It demands clear explanations, accurate calculations and a deep understanding of physical, inorganic and organic chemistry. This guide highlights frequent mistakes and offers targeted advice.

The paper requires balanced equations, energy‑level diagrams and knowledge of electrolysis. Examiner reports reveal that students often struggle with organic synthesis pathways, forget to include state symbols in equations and misapply redox conventions in electrolysis. Transition metal properties and extraction reactivity are other challenging areas. To score highly, you must combine recall with reasoning and show every step.

To prepare effectively:

• Map organic pathways: Practise drawing reaction sequences for alkanes, alkenes and alcohols, showing bond breaking and formation. Include energy diagrams to illustrate exothermic and endothermic steps.

• Show full equations: Write balanced equations with state symbols and charges when appropriate. For electrolysis questions, identify the species oxidised and reduced and state products at each electrode.

• Understand metals and extraction: Review the properties of transition metals and the reactivity series. Explain why a metal can be extracted by electrolysis or reduction and discuss environmental considerations. As the exam approaches, work through past papers and mark schemes to perfect your technique. Download our Organic Chemistry Pathways Guide for a visual summary of synthetic routes and practice questions to secure top marks.