Topic 8A Redox Chemistry
Use this landing page to move between the four Redox Chemistry revision pages of Topic 8. Each card links to a focused page with inline checks, worked examples and exam-style FAQs.
Choose a Redox Chemistry Page
Redox chemistry gives you a way of following electrons through a reaction. These pages build the oxidation number rules, then use them to define oxidation and reduction, to write and combine half-equations, to recognise disproportionation and to classify unfamiliar reactions.
Key idea: Every redox question comes back to the same two ideas: an increase in oxidation number is oxidation and a loss of electrons, a decrease is reduction and a gain of electrons.
Oxidation Numbers
Oxidation numbers: the rules, calculating them in compounds, ions, peroxides and metal hydrides, Roman numerals and writing formulae.
Start revisingElectron Transfer and Half-Equations
Redox as electron transfer: oxidising and reducing agents, oxidation number changes, writing ionic half-equations and combining them into full ionic equations.
Start revisingDisproportionation
Disproportionation: recognising it with oxidation numbers, chlorine in water and alkali, hydrogen peroxide, copper(I) and which species cannot disproportionate.
Start revisingRedox Classification
Classifying reactions with oxidation numbers: redox or not, s-block and p-block examples, metals with acids, and unfamiliar equations.
Start revisingHow to Use These Pages
Start with the oxidation number rules until you can assign a value to any atom quickly. Then use electron transfer and half-equations to describe what the electrons do, disproportionation for the special case of one element going both ways, and redox classification to practise on equations you have not seen before.
Exam focus: In a redox explanation always quote the element, its two oxidation numbers and the word oxidised or reduced. Naming the oxidising agent means naming the species that is reduced.
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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