Carbon is the only element that gets a whole branch of chemistry to itself. Because carbon atoms can form four strong covalent bonds — including bonds to other carbon atoms — they build chains and rings of almost any size, and that ability makes a near-limitless family of compounds possible. The name organic chemistry comes from the original sources of these compounds: living, or once-living, material. C7 follows that carbon from its biggest modern source — crude oil — through the fuels in cars and aircraft, to the alcohols, acids and polymers that the petrochemical industry builds from it.
🧭 How this topic splits by tier and course
C7 (4.7) has the biggest Combined/Triple split of any chemistry topic, so check what you actually need:
- Everyone — sections 1–4: crude oil, hydrocarbons and alkanes, fractional distillation, properties of hydrocarbons and combustion, and cracking (including the bromine water test for alkenes).
- Triple (Chemistry only) T — sections 5–11: the structure and reactions of alkenes, alcohols, carboxylic acids and esters, and all of the polymer chemistry.
- Higher Tier H (within Triple) — explaining why carboxylic acids are weak acids (section 8), and the whole of condensation polymerisation and amino acids (section 10).
There is no required practical in C7 — but fuels questions love to borrow from other topics: pollutants from burning fuels (C9), energy released by burning fuels (C5) and intermolecular forces (C2) all turn up in organic chemistry questions, and they’re flagged where they do.