Food cans are made from steel coated with tin. Buckets are made from steel coated with zinc. The order of reactivity is zinc > iron > tin. Both coatings are scratched through to the steel and the objects are left in damp air.
Which is correct?
The zinc-coated steel rusts faster, because zinc reacts with water faster than tin does
The tin-coated steel rusts faster, because iron is more reactive than tin and is oxidised first
Both rust at the same rate, because neither coating now keeps air and water away from the steel
Neither rusts at first, because each coating metal is oxidised in preference to the iron
42 exam-style questions on Edexcel GCSE Chemistry 6.1 Transition metals, alloys and corrosion, covering 6.1.1 Properties of transition metals, 6.1.2 Corrosion and its prevention, and 6.1.3 Alloys and the uses of metals. Each one has a worked solution and a mark scheme showing where the marks go.