Topic 8C Group 7
Use this landing page to move between the four Group 7 revision pages of Topic 8. Each card links to a focused page with inline checks, worked examples and exam-style FAQs.
Choose a Group 7 Page
Group 7 is the p-block mirror of Group 2: the same reasoning about size and shielding, but now the halogens gain electrons instead of losing them. These pages cover the physical trends, the halogens as oxidising agents, the disproportionation reactions of chlorine and the halide ions as reducing agents together with their tests.
Key idea: Oxidising power falls down the group because the incoming electron is further from the nucleus and more shielded; reducing power of the halide ions rises for exactly the same reason.
Trends in the Halogens
The trends in Group 7: states, colours, boiling points, electronegativity, reactivity and predictions for fluorine and astatine.
Start revisingHalogens as Oxidising Agents
The halogens as oxidising agents: displacement reactions, colours in water and cyclohexane, reactions with metals and hydrogen, and the reactivity trend.
Start revisingDisproportionation Reactions of Chlorine
The disproportionation of chlorine with water and with cold and hot alkali, bleach, water treatment and analogous halogen reactions.
Start revisingHalide 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.
Start revisingHow to Use These Pages
Begin with the trends so that every later explanation has a cause. The displacement reactions, the chlorine reactions and the halide reactions are then three sets of redox equations to learn with their colours and observations.
Exam focus: Track chlorine with oxidation numbers in every disproportionation equation, and always say which acid is used to acidify a test and why.
Copyright notice: This revision page, including its written explanations, layout and teaching sequence, is produced for Online Learning System by Dr. Mohammed Al-Fatah. It is intended for student revision and may not be copied, redistributed or republished without permission.
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