A student tests how well different substances conduct electricity.
The table shows the results.
| Substance | Type of substance | Conducts when solid? | Conducts when molten? | Conducts when dissolved in water? |
|---|---|---|---|---|
| potassium bromide | ionic | no | yes | yes |
| glucose | simple molecular | no | no | no |
| lead bromide | ionic | no | yes | does not dissolve |
| copper | metal | yes | yes | does not dissolve |
Give the name of the charged particles that carry the current in molten potassium bromide.
Molten potassium bromide is decomposed when it conducts. Predict the product at each electrode.
Suggest why lead bromide was not tested as a solution.
Explain the results in the table in terms of the particles in each substance.
52 exam-style questions on Edexcel GCSE Chemistry 4.2 Electrolytic processes, covering 4.2.1 Electrolytes and the process of electrolysis, 4.2.2 Products of electrolysis using inert electrodes, 4.2.3 Half equations, oxidation and reduction in electrolysis, and 4.2.4 Electrolysis of copper sulfate and purifying copper. Each one has a worked solution and a mark scheme showing where the marks go.