Cambridge IGCSE Chemistry 0620 Past Papers 2026

Multiple Choice (Core/Extended)

Duration: 45m

Theory (Core/Extended)

Duration: 1h 15m

Practical / Alternative to Practical

Duration: 1h 15m (Paper 5) / 1h (Paper 6)

Qualitative analysis and ion tests

Every examiner report flags this as a major weakness. Halide tests (acidified AgNO₃: Cl⁻=white, Br⁻=cream, I⁻=yellow precipitate), sulfate test (acidified BaCl₂ → white precipitate), flame test colours, and gas tests are consistently poorly recalled.

Paper 1/2, Paper 3/4, Paper 5/6

Organic chemistry — displayed formulae, naming, and functional groups

Examiners note: 'Most of the questions on organic chemistry were challenging.' Students confuse ethane/ethene, forget O–H bonds in alcohols and carboxylic acids, draw pentavalent carbons, and cannot name esters or draw polymer repeat units correctly.

Paper 1/2, Paper 3/4

Dynamic equilibrium — definition and Le Chatelier applications

Students say 'concentrations are equal' instead of 'constant', omit 'rate' from the definition, and use incorrect language like 'shifts to the endothermic side'. The correct terms are 'shifts to the left/right'.

Paper 3/4

Electrolysis — aqueous vs molten products

Students consistently predict sodium at the cathode in aqueous NaCl electrolysis. The rule is simple: reactive metals (above H in reactivity series) are NOT produced in aqueous solution — hydrogen forms instead.

Paper 1/2, Paper 3/4

Kinetic particle model — arrangement, separation, and motion

Students confuse arrangement with motion, write 'particles are separated' (just restating the question), or give vague descriptions. Must be specific: solid = fixed positions vibrating; liquid = close together sliding past each other; gas = far apart moving randomly at high speed.

Paper 3/4

Environmental chemistry — pollutant sources and solutions

Students cannot name specific sources ('cars' is too vague — say 'exhaust fumes from vehicles') or specific solutions to acid rain and climate change. Adverse effects of SO₂, CO, and CH₄ are frequently confused.

Paper 3/4

Rates of reaction — collision theory with correct language

Students write 'more collisions' instead of 'greater frequency of collisions'. Few mention that 'a greater proportion of particles have energy greater than or equal to the activation energy' when explaining temperature effects.

Paper 3/4

Blast furnace reactions and role of limestone

Students don't know that: (1) coke burns in hot air to form CO₂, (2) CO₂ reacts with more coke to form CO, (3) CO reduces iron ore, (4) limestone decomposes to CaO which removes SiO₂ impurities as slag. 'Calcium carbonate is a catalyst' is a common wrong answer.

Paper 3/4

Salt preparation methods

Students confuse filtrate with residue, don't know the crystallisation method (heat to point of crystallisation, cool, filter, dry with filter paper), and rarely know that titration is used for soluble salts from soluble bases.

Paper 3/4