A steel hot-water tank contains water with dissolved oxygen. A zinc rod attached inside the tank helps to protect the steel from rusting. During maintenance, a worker suggests replacing the zinc rod with an iron rod.
Explain why the iron rod would not provide the same protection as the zinc rod.
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.