Reactions of the halogens: including displacement practical
I can write word and symbol equations to show how Group 7 elements react.
Reactions of the halogens: including displacement practical
I can write word and symbol equations to show how Group 7 elements react.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- Halogens can be dissolved in water to form acidic solutions.
- A more reactive halogen can displace a less reactive one from a compound.
- Group 7 elements react with Group 1 and 2 metals to form salts.
- The chemical test for chlorine involves passing the gas over damp blue litmus paper.
Keywords
Displacement - reaction is where a more reactive element replaces a less reactive element in a compound.
Solution - is formed when a substance dissolves in a liquid.
Halides - are the name of salts formed from halogens, e.g. sodium chloride (NaCl).
Common misconception
Halogen solutions are coloured and sometimes it can be difficult to determine colour changes during displacement reactions.
Displacement of iodine gives the darkest colour change (turns brown), while bromine will provide one which is lighter (turns orange).
Equipment
Chlorine, bromine and iodine solutions, chloride, bromide and iodide solutions (Group 1 halides work well), spotting tiles and pasteur pipettes.
Content guidance
- Risk assessment required - equipment
Supervision
Adult supervision required
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Starter quiz
6 Questions
Ionic compounds formed from positive and negative ions.
A salt formed from a halogen.
Two atoms of the same type chemically bonded together.
Non metallic elements which react with metals to form halide salts.