Cambridge IGCSE·Co-ordinated Sciences 0654·Chemistry
Organic Chemistry
Key knowledge — Organic Chemistry
Formulas & equations
Combustion of alkane: CₙH₂ₙ₊₂ + O₂ → CO₂ + H₂OAddition of H₂ to alkene: CₙH₂ₙ + H₂ → CₙH₂ₙ₊₂ (hydrogenation)Fermentation: C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ (ethanol production)Esterification: alcohol + carboxylic acid ⇌ ester + water (concentrated H₂SO₄ catalyst)
Key facts & rules
- Alkanes: saturated (only C−C single bonds). General formula CₙH₂ₙ₊₂. Methane (CH₄), ethane (C₂H₆), propane, butane.
- Alkenes: unsaturated (contain C=C double bond). General formula CₙH₂ₙ. Ethene (C₂H₄), propene.
- Test for alkene: bromine water → decolourises (goes from orange to colourless).
- Cracking: long-chain alkanes → shorter alkanes + alkenes (thermal or catalytic cracking).
- Addition polymerisation: alkene monomers → polymer (e.g. ethene → poly(ethene)).
- Fractional distillation of crude oil: different chain lengths have different boiling points — separated by size.
IGCSE Chemistry — Organic chemistry
3056 Cambridge IGCSE 0654 chemistry past paper questions on organic chemistry, organised by subtopic. Pick a subtopic to start practising.
About organic chemistry on IGCSE 0654
Hydrocarbons, fuels, alkanes, alkenes, alcohols and carboxylic acids, addition and substitution reactions, and polymers. The largest Chemistry topic in this dataset.