A student places a sample of calcium bromide between two electrodes connected to a direct current supply and an ammeter. The table shows the current readings.
| State of calcium bromide | Current reading |
|---|---|
| Solid | 0.00 mA |
| Molten | 12.4 mA |
Explain the difference between the readings and give a justified prediction of the reading if the calcium bromide were dissolved in water.
76 exam-style questions on AQA GCSE Chemistry 4.3 Electrolysis, covering 4.3.1a The process of electrolysis, 4.3.1b Half equations in electrolysis, 4.3.2 Electrolysis of molten ionic compounds, 4.3.3 Using electrolysis to extract metals, 4.3.4 Electrolysis of aqueous solutions, and 4.3.5 Representation of reactions at electrodes as half equations. Each one has a worked solution and a mark scheme showing where the marks go.