Science at key stage 3 (Year 7)
Unit 7F: Simple chemical reactions
Section 2: a. How do acids react with metals?
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Objectives |
| Children should learn: |
- how to carry out a test for hydrogen
- that acids can be corrosive
- that acids react with some metals to produce new substances, including hydrogen
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Activities |
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Outcomes |
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Children: |
- Remind pupils of earlier descriptions of acids as corrosive and show some examples of corroded metals. Establish through a quick class experiment that when an acid is added to a metal,
eg zinc, magnesium, bubbles are made.
- Demonstrate an appropriate method for testing the gas produced and explain that a gas behaving in this way is hydrogen.
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- describe and carry out the lighted splint test for hydrogen
- generalise that when an acid is added to many metals, hydrogen is produced and the metal disappears or becomes smaller
- relate the disappearance of the metal to the idea of corrosion
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Points to note |
- In key stage 2, pupils are likely to have seen reactions of acids producing a gas (
unit 6D 'Reversible and irreversible changes') and have encountered common gases (
unit 5C 'Gases around us'). However, they will not have tested or identified gases produced.
- It may be helpful to introduce the terms
'reactant' and
'product'.
Safety
- eye protection should be used. 0.4 mol dm-3 acid is suitable. Acids are not necessarily corrosive and most of those encountered by pupils will not be.
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This unit is divided into sections. Each section contains a sequence of
activities with related objectives and outcomes. You can view this unit by
moving through the sections or print/download the whole unit.
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