A manufacturer investigates how iron powder changes the oxygen concentration in sealed food containers.
| Container | Contents | Initial oxygen concentration (%) | Oxygen concentration after 7 days (%) | Observation after 7 days |
|---|---|---|---|---|
| P | Iron powder and water | 20.9 | 4.8 | A rust-coloured solid formed |
| Q | Iron powder and a drying agent | 20.9 | 20.9 | No visible change |
Calculate the decrease in oxygen concentration in container P.
Explain why the oxygen concentration decreased in container P but did not decrease in container Q.
Predict whether iron powder would rust in a sealed container containing water but no oxygen. Give a reason for your prediction.
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.