An uncoated iron balance weight is kept in a sealed display case containing dry air. It has not rusted.
Four possible changes are shown in the table.
| Change | Alteration to the conditions |
|---|---|
| 1 | Add water vapour without removing any of the air |
| 2 | Replace the air with dry oxygen |
| 3 | Remove all of the air, then add water vapour |
| 4 | Paint the weight, then add water vapour |
Which change would cause the iron balance weight to start rusting?
Change 3
Change 4
Change 2
Change 1
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.