A polymer is needed for a flexible hose that carries water at 90 ∘C90\,^\circ\mathrm{C}90∘C in a dishwasher. The softening temperature of the polymer must be at least 20 ∘C20\,^\circ\mathrm{C}20∘C above the temperature of the water, and the polymer must not absorb water.
| Polymer | Softening temperature in ∘C^\circ\mathrm{C}∘C | Flexibility | Effect of hot water |
|---|---|---|---|
| W | 105 | flexible | none |
| X | 115 | flexible | none |
| Y | 160 | rigid | none |
| Z | 150 | flexible | absorbs water and swells |
Which polymer is most suitable?
W
X
Y
Z
37 exam-style questions on Edexcel GCSE Chemistry 10.3 Polymers, covering 10.3.1 Addition polymerisation of alkenes, 10.3.2 Uses and properties of polymers, 10.3.3 Condensation polymers and polyesters, 10.3.4 Problems with polymers and recycling, and 10.3.5 Natural polymers: DNA, starch and proteins. Each one has a worked solution and a mark scheme showing where the marks go.