Redox reactions

Learning objectives

Use the terms oxidation (gain of oxygen) and reduction (loss of oxygen), and identify redox reactions as reactions in which oxidation and reduction take place at the same time

Identify which substance is oxidised and which is reduced in a redox reaction

Define oxidation as loss of electrons and reduction as gain of electrons, and identify oxidation and reduction in ionic equations and half-equations (Extended)

Use a Roman numeral to show the oxidation number of an element in a compound, e.g. iron(III) chloride, and, at Extended, use oxidation numbers to identify redox reactions: uncombined elements are 0, a monatomic ion has the charge on the ion, the oxidation numbers in a compound sum to zero and in an ion sum to its charge

Define an oxidising agent as a substance that oxidises another substance and is itself reduced, and a reducing agent as one that reduces another substance and is itself oxidised; identify them in reactions and use the colour changes of acidified aqueous potassium manganate(VII) (purple to colourless) and aqueous potassium iodide (colourless to brown) to detect redox reactions (Extended)