Uncoated steel washers were stored in three sealed packages for eight weeks. One package contained a drying agent. Oxygen had been removed from a different package. The third package was unchanged.
| Package | Oxygen concentration (%) | Water vapour concentration (g/m³) | Steel surface covered by rust after eight weeks (%) |
|---|---|---|---|
| P | 20.9 | 0.0 | 0 |
| Q | 0.0 | 8.0 | 0 |
| R | 20.9 | 8.1 | 35 |
Explain which package contained the drying agent and why the results were different for the three packages.
118 exam-style questions on AQA GCSE Chemistry 10.3 Using materials, covering 10.3.1 Corrosion and its prevention, 10.3.2 Alloys as useful materials, and 10.3.3 Ceramics, polymers and composites. Each one has a worked solution and a mark scheme showing where the marks go.