The table shows some properties of four materials.
| Material | Strength (MPa) | Density (g/cm3\mathrm{g/cm^{3}}g/cm3) | Corrodes in wet air? | Cost per kg (£) |
|---|---|---|---|---|
| Aluminium alloy | 310 | 2.7 | no | 2.50 |
| Carbon fibre composite | 600 | 1.6 | no | 30.00 |
| Poly(propene) | 35 | 0.9 | no | 1.20 |
| Steel | 400 | 7.8 | yes | 0.80 |
A company makes low-cost bicycle frames. The frame material must have a strength above 250 MPa and must not corrode.
Which is the cheapest material that meets these conditions?
Aluminium alloy
Carbon fibre composite
Poly(propene)
Steel
61 exam-style questions on OCR GCSE Chemistry 6.1 Improving processes and products, covering 6.1.1 Extracting metals industrially and by electrolysis, 6.1.2 Life cycle assessment and recycling, 6.1.3 Biological methods of metal extraction, 6.1.4 The Haber process and the production of fertilisers, 6.1.5 Alloys and their uses, 6.1.6 Corrosion and its prevention, 6.1.7 Comparing and selecting materials, and 6.1.8 Industrial conditions, rate and position of equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.