ElectrolysisKey Facts

Key Facts to Memorise

Part of Electrolysis of Aluminium · GCSE GCSE Chemistry revision

This key facts covers Key Facts to Memorise within Electrolysis of Aluminium for GCSE Chemistry. Revise Electrolysis of Aluminium in Electrolysis for GCSE Chemistry with 21 exam-style questions and 14 flashcards. Use this page as part of a wider topic revision path rather than treating it as an isolated fact. It is section 7 of 13 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 7 of 13

Practice

21 questions

Recall

14 flashcards

📌 Key Facts to Memorise

Bauxite is the ore containing aluminium oxide (Al₂O₃)
Cryolite (Na₃AlF₆) lowers melting point from 2072°C to ~950°C — saves huge amounts of energy!
Cathode half equation: Al³⁺ + 3e⁻ → Al (reduction — aluminium ions gain electrons)
Anode half equation: 2O²⁻ → O₂ + 4e⁻ (oxidation — oxide ions lose electrons)
Carbon anodes burn away because O₂ reacts with hot carbon: C + O₂ → CO₂
Anodes need regular replacement — this is an ongoing cost of the process
Electrolysis uses HUGE amounts of electricity — very expensive!
Recycling aluminium saves 95% of the energy vs extracting from ore
Aluminium is used in aircraft, drinks cans, power cables (low density + good electrical conductor)
The cathode is made of steel (lined with carbon), the anodes are carbon/graphite

Quick Check: Why is cryolite added to the aluminium oxide in the Hall-Héroult process?

Keep building this topic

Read this section alongside the surrounding pages in Electrolysis of Aluminium. That gives you the full topic sequence instead of a single isolated revision point.

Key Definitions Common Misconceptions The Metal That Changed History The Hall-Heroult Cell — Click to Explore

Practice Questions for Electrolysis of Aluminium

Why is aluminium extracted by electrolysis rather than by reduction with carbon?

A. Aluminium is less reactive than carbon
B. Aluminium is more reactive than carbon
C. Aluminium does not form ions
D. Carbon reacts with aluminium to form carbides

1 markfoundation

Explain why aluminium is extracted by electrolysis rather than by reduction with carbon.

2 marksstandard

Quick Recall Flashcards

What does OIL RIG stand for?

Oxidation Is Loss (of electrons), Reduction Is Gain (of electrons). At the Anode = Oxidation (loss). At the Cathode = Reduction (gain).

Why do the carbon anodes need replacing regularly?

At 950°C, the oxygen produced at the anode reacts with the hot carbon: C + O₂ → CO₂. The carbon is gradually burned away, so the anodes must be replaced periodically.

21 questions on Electrolysis of Aluminium — practise free

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Key Definitions

Common Misconceptions