Loading…
Loading…
GCSE Chemistry · key term
A substance added to dissolve aluminium oxide and lower the temperature needed for electrolysis.
Used by AQA and OCR
Specification 4.4.3.3 · Paper 1
Revise: Electrolysis of AluminiumAluminium oxide is dissolved in molten cryolite. The resulting molten mixture is the electrolyte: its ions can move and carry charge. Cryolite lowers the temperature needed to keep the mixture liquid, reducing the energy needed for heating.
Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Higher), Paper 4 (Higher)
A substance used as a molten solvent for aluminium oxide so that electrolysis can take place at a lower temperature.
Distinguish the roles of the materials: aluminium oxide supplies the aluminium ions; cryolite lowers the temperature needed for a molten electrolyte.
Create a free account to read GCSE Chemistry revision notes for your exam board and track your progress.
In the extraction cell it is dissolved in molten cryolite, which allows electrolysis to take place at a lower temperature than melting pure aluminium oxide. The liquid mixture is the electrolyte: it contains aluminium and oxide ions that can move. The cell still needs substantial energy, both to keep it hot and to supply electricity.