This diagram covers Half Equations — Must Know! within Electrolysis of Aluminium for GCSE Chemistry. Revise Electrolysis of Aluminium in Electrolysis for GCSE Chemistry with 20 exam-style questions and 0 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 4 of 13 in this topic. Focus on the labels, the relationships between parts, and the explanation that turns the diagram into an exam-ready answer.
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Section 4 of 13
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20 questions
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⚗️ Half Equations — Must Know!
🔵 CATHODE (−) — Reduction (Gain of electrons)
Al³⁺ + 3e⁻ → Al
Aluminium ions GAIN 3 electrons → aluminium metal atoms
Molten aluminium sinks to the bottom (it's denser than the electrolyte)
🔴 ANODE (+) — Oxidation (Loss of electrons)
2O²⁻ → O₂ + 4e⁻
Oxide ions LOSE electrons → oxygen gas molecules
Oxygen reacts with hot carbon anode: C + O₂ → CO₂
Overall equation: 2Al₂O₃ → 4Al + 3O₂
(Requires electrical energy — this is NOT a spontaneous reaction!)