Pearson Edexcel International GCSE Chemistry · specification 4CH1 · Paper 2 | Whole paper: All content including bold C statements · Free · no account needed
4(c) Alkanes and (d) alkenes (4CH1 specification)
Two homologous series, one saturated and one not, and the test that tells them apart in seconds.
Learn it on Incandio
The 4 Incandio pages that teach this — each explained in full, then proved in marked questions, taught back to an AI pupil and defended in a debate. Completely free.
- Pollutants And Acid Rain — One pollutant comes out of the fuel and one comes out of the air — and telling them apart decides which fix works.
- Cracking — Breaking long molecules nobody wants into short ones everybody does — and the reason a refinery has to.
- Alkanes — The family that is already full — what saturation means, and the one reaction that gets past it.
- Alkenes — Two hydrogens missing, one double bond gained — and a family that is far more useful for it.
The teaching route this belongs to: Topic 4 · Organic chemistry (Chemistry) — the lessons in order, with every gate.
Specification coverage
Topic 4 Organic chemistry (c) Alkanes and (d) alkenes — statements 4.14–4.24C (includes bold C statements assessed on Paper 2 only)
Assessment objectives: AO1, AO2. Suggested learning time: 80 minutes.
Required knowledge
- The general formulae of alkanes and alkenes
- The meaning of homologous series, saturated and unsaturated
- Naming and drawing the first four members of each series
- The test for unsaturation using bromine water
- Addition reactions of alkenes, and addition polymerisation
- Bold C statements: isomerism and further reactions
Required skills
- Draw displayed formulae correctly, with every bond shown
- Write equations for addition reactions
- Deduce a polymer's repeat unit from its monomer, and vice versa
How it is examined
- Multiple-choice and short-answer recall
- Application of the content to an unfamiliar context
- Extended open-response, marked on the quality of a connected explanation
Common mistakes
- Drawing a displayed formula with a missing hydrogen. Every bond must be shown, and carbon always forms four.
- Saying bromine water 'turns brown' for an alkene. It is decolourised — orange-brown to colourless.
- Forgetting the continuation bonds on a polymer repeat unit.
This page maps the specification. The pages above teach it, and the Chemistry lessons hold the whole course — completely free.