Organic Chemistry
Organic chemistry can feel like an avalanche of names and drawings — but almost every question in this unit reduces to one fact: carbon forms exactly four bonds and loves bonding to itself. Once that's automatic, naming, isomers, hydrocarbons, alcohols, acids, esters and polymers are all just that one idea dressed up differently. These notes work through the logic in the order examiners actually build on it — bonding first, then naming, then reactions.
Overview
What organic chemistry actually studies
Organic chemistry is the chemistry of carbon compounds — specifically, compounds where carbon is covalently bonded to hydrogen and, often, oxygen, nitrogen or halogens. Every skill in this unit (naming, drawing, predicting reactions) traces back to two structural facts about carbon: it always forms four bonds (tetravalency), and it bonds to itself extensively (catenation).
- Millions of organic compounds exist because carbon's four bonds can be arranged in endless combinations — long chains, branches, rings, single/double/triple links.
- A handful of simple carbon compounds (CO₂, carbonates, cyanides) are classed as inorganic by convention, even though they contain carbon.
- This unit builds in a fixed order: bonding → naming → isomerism → hydrocarbon families → functional groups → polymers → industrial separation (crude oil).
The shape of the chapter
Command terms this unit tests hardest
| Command term | What it demands | AO | Mark-earning move |
|---|---|---|---|
| Construct | Build a diagram, structure or table from given information | Knowing & understanding / Communication | Must show every atom/bond/electron explicitly — a correct description in words instead of the drawing scores zero. |
| State | Give a specific, concise answer with no reasoning | Knowing & understanding | One clean statement is enough for full marks; extra unrequired explanation isn't rewarded (or penalised unless it contradicts the answer). |
| Explain | Give reasons or a mechanism, not just an observation | Applying / reasoning | Needs a because…therefore… chain — a bare fact with no linking reason only earns partial credit. |
| Deduce | Reach a conclusion from information given in the question, not general theory | Reasoning with data | Must reference the actual numbers/data given — a generic textbook answer not tied to the data loses marks. |
| Distinguish | State differences between two or more items | Analysing | Needs a paired comparison (X does…, whereas Y does…) — describing only one item scores zero. |
Key point
Overview