Identify which substance is oxidised and which is reduced in oxygen-transfer reactions.

In the subtopic The reactivity series, this learning objective focuses on identify which substance is oxidised and which is reduced in oxygen-transfer reactions. It sits within Reactivity of metals for AQA GCSE Chemistry 8462 Unit 4.4, so the explanation must stay anchored to chemical changes rather than drifting into a general chemistry idea. Approved keywords to use include which, substance, reduced, oxygen-transfer, oxidised. Reduction. means the process in which a substance gains electrons or loses oxygen Avoid the mistake of students often confuse oxidation with reduction, thinking that oxidation involves gaining oxygen instead of losing electrons; instead, remember that oxidation is defined as the loss of electrons, while reduction is the gain of electrons. Focus on the electron transfer process to clarify these concepts For exam answers, memorize the definitions of oxidation and reduction in terms of oxygen transfer: oxidation is the gain of oxygen, and reduction is the loss of oxygen Keep acid, alkali and base distinct; keep oxidation and reduction distinct; do not mix reduction with displacement; keep electrolysis separate from electroplating; distinguish anode from cathode, positive ions from negative ions, oxidation state from ionic charge, and strong acid from concentrated acid.