Study Hub

Study Guides

This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.

Back to Study HubBrowse Year 11 Science Guides

Year 11 - Science

Electrolysis of molten salts

Electrolysis

Unit Summary

This unit focuses on electrolysis, electrode reactions, and predicting products, including competing reactions in solutions. It explains metal extraction through electrolysis and writing ionic equations. It also covers tests for gases like oxygen, hydrogen, carbon dioxide, and chlorine.

Lesson Summary

You will learn to explain why salts can be electrolysed when in their liquid state, and describe the reactions taking place.

Key Notes

  • 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.

Vocabulary To Learn

  • 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 Mistakes To Avoid

  • Pupils often think that, during electrolysis, the charge carriers are electrons and not ions.

3 Quick Questions (With Answers)

1. Explain the scientific idea in this lesson using two key points.

A solid ionic compound cannot conduct electricity. Salts are ionic compounds which can be electrolysed when they are in the molten state.

2. Define this scientific word and use it in context. 'molten'

the term used to describe a liquid substance formed by heating ionic compounds and metal ores. Include the word in a full scientific explanation, not as a single label.

3. Correct this common scientific misunderstanding.

Mistake: Pupils often think that, during electrolysis, the charge carriers are electrons and not ions. Correction: 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.

More Lessons In This Unit

Browse all guides in the Year 11 Science guide library.