Alcohols, carboxylic acids and polymers — GCSE Chemistry practice questions

Question 1

Volunteers on a beach clean-up in Indonesia find plastic bottles that were thrown away many years ago and are hardly changed.

Why do plastics stay in the environment for so long?

Accepted Answer

A: Bacteria and other microorganisms cannot break them down.. Plastics are non-biodegradable: bacteria and other microorganisms cannot break them down, so bottles last for many years in landfill and in the oceans.

Question 2

Fishing lines are made of nylon, drinks bottles of PET, and hair contains the protein keratin.

Which row is correct?

Accepted Answer

A: polyamide · polyester · polyamide. Nylon is a synthetic polyamide and proteins are natural polyamides: both have amide linkages. PET is made from a dicarboxylic acid and a diol, so it has ester linkages and is a polyester (a condensation polymer, not an addition polymer).

Question 3

Fig. 1 shows part of the chain of a polyamide made in a materials laboratory. Each box stands for a chain of carbon atoms.

How many amide linkages are in this part of the chain?

Accepted Answer

B: 3. Each amide linkage is one –C(=O)–N(H)– group joining two boxes. The four boxes are joined by three linkages, so there are 3 amide linkages. (The 4 counts boxes; the 6 counts each C=O and each N–H separately.)

	nylon	PET	protein
A	polyamide	polyester	polyamide
B	polyamide	polyester	polyester
C	polyamide	addition polymer	polyamide
D	polyester	polyamide	polyamide