2.1.5
Redox
Section 2.1.5 covers the rules for oxidation numbers in elements, compounds and ions, writing formulae from oxidation numbers and using Roman numerals, oxidation and reduction as electron transfer and as changes in oxidation number, the redox reactions of metals with acids, and interpreting unfamiliar redox equations. Disproportionation is revision support here and is examined in 3.1.3 for chlorine.
Revision Notes
4 revision notes, in the order the specification teaches them.
Oxidation Numbers
Oxidation numbers: the rules, calculating them in compounds, ions, peroxides and metal hydrides, Roman numerals and writing formulae.
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Electron 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.
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Disproportionation
Disproportionation: recognising it with oxidation numbers, chlorine in water and alkali, hydrogen peroxide, copper(I) and which species cannot disproportionate.
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Redox Classification
Classifying reactions with oxidation numbers: redox or not, s-block and p-block examples, metals with acids, and unfamiliar equations.
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Redox Map
OCR A Level Chemistry A · 2.1.5 Redox
The whole topic on one A4 page: oxidation number rules, Roman numerals, half-equations, agents and a table of polyatomic ions with their charges.
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Specification
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2.1.5
- c
use of a Roman numeral to indicate the magnitude of the oxidation number when an element may have compounds/ions with different oxidation numbers
Revise - e
redox reactions of metals with acids to form salts, including full equations (see also 2.1.4 c)
Revise - f i
interpretation of redox equations in (e) to make predictions in terms of oxidation numbers and electron loss/gain
Revise - f ii
interpretation of unfamiliar redox reactions to make predictions in terms of oxidation numbers and electron loss/gain
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