Corrosion and its prevention
Lesson details
Learning outcome
I can describe corrosion in detail, including chemical equations, and describe what actions can be taken to prevent corrosion.
Key learning points
- Corrosion is a general process of degradation of metals through various causes.
- Rusting is a specific type of corrosion, affecting iron in the presence of air and moisture.
- A metal oxide layer can protect the underlying metal if the oxide forms a physical barrier.
- Some coatings are reactive and contain a more reactive metal to provide sacrificial protection, e.g. zinc to galvanise.
- Electroplating can be used to improve the appearance and/or the resistance to corrosion of metal objects.
Keywords
Rusting - The corrosion of iron or steel, in the presence of water and oxygen.
Corrosion - The gradual deterioration of a substance when it reacts with substances in the environment, for example when a metal oxidises in air.
Sacrificial protection - Using a more reactive metal to corrode preferentially, to protect another metal from corrosion.
Tarnishing - The process by which a thin, discoloured layer forms on the surface of a metal due to reactions with the environment, e.g. oxidation.
Electroplating - A process that uses electricity to deposit a thin layer of metal onto the surface of another conductive object.
Common misconception
Students often believe rusting refers to the oxidation of any metal, and that corrosion is linked to the hazard 'corrosive'.
Highlight the conditions required for rusting, and the general description of corrosion.
Teacher tip
A demonstration of the ways corrosion of metals can be limited (specifically iron and rusting) would be good to see, but may take time to set up. Really emphasise the key differences and similarities between the key words.
Equipment
None required.
Licence
except where otherwise stated. See Oak's terms & conditions (Collection 2).Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Transition metals like copper and zinc are used in electrical applications because they are excellent of electricity.
Q2.When a metal reacts with oxygen, it often forms a .
Q3.A is formed when two or more elements are chemically bonded together.
Q4.Arrange the following metals in order of reactivity with oxygen (most reactive at the top, least reactive at the bottom).
Q5.The ability of a metal to be hammered into thin sheets without breaking is called...
Q6.The resistance of a metal to being scratched or dented is called .
Assessment exit quiz
6 Questions
Q1.What is sacrificial protection?
Q2.Which metal is often used to galvanise iron?
Q3.Which process involves the use of electricity to prevent corrosion and improve appearance?
Q4.What is the purpose of using a more reactive metal in sacrificial protection?
Q5.Rusting is a specific type of corrosion affecting in the presence of water and oxygen.
Q6.Complete the word equation for the rusting of iron.
iron + → (hydrated) iron(Ⅲ) oxide
To help you plan your 11 chemistry lesson on: Corrosion and its prevention, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 11 chemistry lesson on: Corrosion and its prevention, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 chemistry lessons from the Industrial chemistry unit, dive into the full secondary chemistry curriculum, or learn more about lesson planning.