Oxidation numbers
What Oxidation numbers means in Chemistry A-Level, as defined for OCR.
Definitions of Oxidation numbers
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Reference: OCR
Values assigned to each atom so that the elements which change can be identified and the total increase equalised with the total decrease.
A bookkeeping tool assigned to each element in an equation using the standard rules, and tracked to see how they change.
Oxidation is an increase in oxidation number and reduction is a decrease, so the changes show which species is oxidised.
Topics that use Oxidation numbers
- Redox (OCR A-Level)
- Redox and electrode potentials (OCR A-Level)
Related terms
- Electron transfer
- Half-equations
- Oxidising Agent
- Oxidising and reducing agents
- Reducing agent
- Applying familiar redox method to unfamiliar systems
- Calculating an unknown value from known contributions
- Concentration effects
Using Oxidation numbers in the exam
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