(a) Poly(chloroethene) is an addition polymer made from chloroethene, CH₂=CHCl.
Draw the repeat unit of poly(chloroethene). [2]
(b) Give one reason why addition polymers cause problems in landfill sites. [1]
(c) Polyesters are condensation polymers. State the two types of monomer used to make a polyester and name the small molecule also formed. [2]
- (a) two carbon atoms joined by a single C–C bond, with 3 H and 1 Cl attached (CH₂–CHCl) (reject a C=C double bond)(1)
- (a) brackets with extension bonds passing through them and n (accept –[CH₂–CHCl]n–) (dependent on correct repeat unit or a minor slip in it)(1)
- (b) not biodegradable / inert / unreactive / do not break down (allow take up space for a long time)(1)
- (c) a diol and a dicarboxylic acid(1)
- (c) water(1)
- Answer: (a) –[CH₂–CHCl]ₙ– (b) non-biodegradable (c) diol + dicarboxylic acid; water
- Examiner tip: The repeat unit has a SINGLE C–C bond — leaving the double bond in loses the first mark.