This definitions covers Key Definitions within Displacement Reactions for GCSE Chemistry. Revise Displacement Reactions in Chemical Changes for GCSE Chemistry with 20 exam-style questions and 20 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 4 of 12 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Topic position
Section 4 of 12
Practice
20 questions
Recall
20 flashcards
📖 Key Definitions
Displacement reaction: A reaction in which a more reactive element takes the place of a less reactive element in a compound. The more reactive element is oxidised; the less reactive element (or its ion) is reduced.
Spectator ion: An ion that is present in a reaction mixture but does not change during the reaction. It appears on both sides of the full ionic equation and is omitted from the ionic equation.
Oxidation: Loss of electrons (OIL — Oxidation Is Loss). The metal doing the displacing is always oxidised.
Reduction: Gain of electrons (RIG — Reduction Is Gain). The metal ion being displaced is always reduced.
Ionic equation: An equation that shows only the species that change during the reaction — spectator ions are removed. For displacement: Metal + Metal ion → Metal ion + Metal.