Electrolysis of molten salts
I can explain why salts can be electrolysed when in their liquid state, and describe the reactions taking place.
Electrolysis of molten salts
I can explain why salts can be electrolysed when in their liquid state, and describe the reactions taking place.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- A solid ionic compound cannot conduct electricity.
- Salts are ionic compounds which can be electrolysed when they are in the molten state.
- Gases may be formed at the electrodes.
- Freely moving ions can reach the electrodes and undergo oxidation or reduction.
- A non-metal always forms at the positive electrode, and a metal forms at the negative electrode.
Keywords
Molten - the term used to describe a liquid substance formed by heating ionic compounds and metal ores.
Anode - A positively charged electrode, in an electrolysis cell, to which the anions are attracted.
Cathode - A negatively charged electrode, in an electrolysis cell, to which the cations are attracted.
Anion - A negatively charged ion
Cation - A positively charged ion
Common misconception
Students often think that during electrolysis the charge carriers are electrons and not ions.
Revisit the structure of ionic compounds in the solid and liquid states. Point out that there are no delocalised electrons. The electrons are associated with ions and so are unable to move through the electrolyte. Ions can move in the liquid state.
To help you plan your year 11 combined science lesson on: Electrolysis of molten salts, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 11 combined science lesson on: Electrolysis of molten salts, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
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The assessment exit quiz will test your pupils' understanding of the key learning points.
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Explore more key stage 4 combined science lessons from the Electrolysis unit, dive into the full secondary combined science curriculum, or learn more about lesson planning.
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