Iron and steel are essential structural materials, but they are vulnerable to corrosion when exposed to the atmosphere or damp environments.
State the two environmental substances that must react with iron for rusting to take place.
Give the systematic chemical name of the main compound that constitutes rust.
Complete the table below by matching each corrosion prevention method with the most appropriate object from the provided list. Each object should be used only once.
List of objects:
| Method | Example of use |
|---|---|
| Painting | |
| Oiling / greasing | |
| Plastic coating |
Underground steel pipelines are often protected from corrosion by connecting them via electrical wires to buried blocks of magnesium. This setup prevents the steel from corroding even if its surface is scratched and exposed to the soil.
Explain, in terms of reactivity and electron transfer, how the magnesium blocks protect the steel pipeline from corroding.
34 exam-style questions on Edexcel IGCSE Chemistry Reactivity series. Each one has a worked solution and a mark scheme showing where the marks go.