Redox processes and oxidation numbers

Learning objectives

Calculate the oxidation number of an element in a compound or ion, e.g. Mn in MnO₄⁻ or S in S₂O₃²⁻, and name compounds with Roman numerals such as iron(III) chloride

Define oxidation and reduction in terms of electron transfer and change in oxidation number, and identify the oxidising agent and the reducing agent in a reaction

Balance redox equations by matching the total increase and decrease in oxidation number; (A Level) build them by combining half-equations

Recognise disproportionation, where one element is oxidised and reduced in the same reaction, e.g. chlorine with cold aqueous NaOH or 2H₂O₂ → 2H₂O + O₂