Topic 11
Group 17
Topic 11 covers the colours, volatility and bond strengths of chlorine, bromine and iodine, their relative reactivity as oxidising agents including the reactions with hydrogen and the thermal stability of the hydrogen halides, the halide ions as reducing agents with silver ions, ammonia and concentrated sulfuric acid, and the disproportionation reactions of chlorine with cold and hot sodium hydroxide and in water purification.
Revision Notes
4 revision notes, in the order the specification teaches them.
Trends in the Halogens
The trends in Group 17: states, colours, boiling points, electronegativity, reactivity and predictions for fluorine and astatine.
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Halogens as Oxidising Agents
The halogens as oxidising agents: displacement reactions, colours in water and cyclohexane, reactions with metals and hydrogen, and the reactivity trend.
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Disproportionation Reactions of Chlorine
The disproportionation of chlorine with water and with cold and hot alkali, bleach, water treatment and analogous halogen reactions.
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Halide Ions: Reducing Agents and Tests
Halide ions: reducing power with concentrated sulfuric acid, the acidified silver nitrate test and ammonia, and the hydrogen halides with ammonia and water.
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Summary map
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Group 17 Map
Cambridge International AS & A Level Chemistry · Topic 11 Group 17
The whole section on one A4 page: physical trends, displacement, hydrogen halides, chlorine disproportionating, halides with H₂SO₄, and silver nitrate tests.
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Specification
Every specification point in this topic, in the exam board's own words. Rate how confident you are with each one.
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11.1.1
11.1.2
11.1.3
- 11.1.3
interpret the volatility of the elements in terms of instantaneous dipole–induced dipole forces
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11.2.1
11.2.2
11.2.3
11.3.1
11.3.2
11.4.1
- a
describe and interpret, in terms of changes in oxidation number, the reaction of chlorine with cold aqueous sodium hydroxide
Revise - b
describe and interpret, in terms of changes in oxidation number, the reaction of chlorine with hot aqueous sodium hydroxide
Revise - c
recognise the reactions of chlorine with cold and with hot aqueous sodium hydroxide as disproportionation reactions
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11.4.2
- 11.4.2
explain, including by use of an equation, the use of chlorine in water purification to include the production of the active species HOCl and ClO– which kill bacteria
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