The corrosion of iron or steel, in the presence of water and oxygen.

The gradual deterioration of a substance when it reacts with substances in the environment, for example when a metal oxidises in air.

Using a more reactive metal to corrode preferentially, to protect another metal from corrosion.

The process by which a thin, discoloured layer forms on the surface of a metal due to reactions with the environment, e.g. oxidation.

A process that uses electricity to deposit a thin layer of metal onto the surface of another conductive object.

Corrosion and its prevention: including half equations

Chemistry

In the Rates and energy changes unit, pupils learned about how energy changes are always involved in reaction, along with a range of methods for measuring and comparing rates of reaction using properties of reactants and/or products.

Industrial chemistry

Using a more reactive metal to corrode preferentially and protect another metal.

Covering a metal with plastic to prevent air exposure.

Cleaning a metal regularly to prevent tarnishing.

Which metal is often used to galvanise iron?

Which process involves the use of electricity to prevent corrosion and improve appearance?

Rusting is a specific type of corrosion affecting {{}} in the presence of water and oxygen.

Complete the word equation for the rusting of iron.
iron + {{}} → (hydrated) iron(Ⅲ) oxide

O₂ (g) + 2H₂O(l) + 4e⁻ → 4OH⁻(aq)

Fe²⁺(aq) + 2OH⁻(aq) → Fe(OH)₂ (s)

4Fe(OH)₂ (s) + O₂ (g) → 2Fe₂O₃·H₂O(s) + 2H₂O(l)

Which of the following equations is not involved in the rusting process?

Transition metals like copper and zinc are used in electrical applications because they are excellent {{}} of electricity.

When a metal reacts with oxygen, it often forms a {{}}.

A {{}} is formed when two or more elements are chemically bonded together.

Arrange the following metals in order of increasing reactivity with oxygen (most reactive at the top of the list).

Which of the following reactions represents oxidation?

The reactivity of a metal is linked to its ability to {{}}.

This lesson will be removed by end of Summer Term 2025.

Corrosion and its prevention: including half equations

Lesson outcome

This lesson will be removed by end of Summer Term 2025.