Classify halogen derivatives of hydrocarbons on the basis of the carbon atom that carries the halogen. Give one example of each.

1. 1 · Define in one line. Haloalkanes and haloarenes form when a halogen atom replaces a hydrogen atom in an aliphatic or an aromatic hydrocarbon.
2. 2 · Group 1: X on an sp³ carbon. Alkyl halides (1°, 2°, 3°), e.g. (CH₃)₃CBr; allylic, e.g. CH₂=CHCH₂Cl; benzylic, e.g. C₆H₅CH₂Cl.
3. 3 · Group 2: X on an sp² carbon. Vinylic, e.g. CH₂=CHCl; aryl, e.g. C₆H₅Cl.
4. 4 · Name each example. 2-Bromo-2-methylpropane, 3-chloroprop-1-ene, chlorophenylmethane, chloroethene and chlorobenzene.
5. 5 · Link to real life. Chloroethene is polymerised to make PVC pipes.
6. 6 · Close in one line. So the hybridisation of the carbon that holds X decides the class.

Scoring tip: Write sp³ or sp² next to every example; that word earns the mark.