Electrolysis of Molten Ionic Compounds (AQA GCSE Chemistry Combined Science): Revision Notes
📚 Revision Notes
4.3.2 Electrolysis of Molten Ionic Compounds
Electrolysis can also be carried out on molten ionic compounds. When an ionic compound is heated until it melts, the ions are free to move, allowing electrolysis to occur.
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This process is used to extract pure elements, such as metals, from their ores.
Key Points in Electrolysis of Molten Compounds:
- Ionic Compounds: These are compounds made of positive and negative ions, such as metal oxides or salts. In their solid state, the ions are fixed in place and cannot move. When molten, these ions become free to move, making electrolysis possible.
- Molten State: The ionic compound must be heated to a high temperature to become molten. In this state, the ions are mobile and can conduct electricity.
In electrolysis of molten ionic compounds:
- Positive metal ions are reduced at the cathode to form pure metals.
- Negative non-metal ions are oxidised at the anode to form gases or non-metallic elements.