Aluminium sulfate is soluble in water.
Why can aluminium not be extracted by the electrolysis of aluminium sulfate solution?
Hydrogen is produced at the negative electrode instead, because aluminium is more reactive than hydrogen.
Aluminium is produced at the positive electrode instead, where it reacts with oxygen.
Sulfate ions are discharged at the negative electrode instead of aluminium ions.
The solution cannot conduct electricity, because the ions are not free to move.
61 exam-style questions on OCR GCSE Chemistry 6.1 Improving processes and products, covering 6.1.1 Extracting metals industrially and by electrolysis, 6.1.2 Life cycle assessment and recycling, 6.1.3 Biological methods of metal extraction, 6.1.4 The Haber process and the production of fertilisers, 6.1.5 Alloys and their uses, 6.1.6 Corrosion and its prevention, 6.1.7 Comparing and selecting materials, and 6.1.8 Industrial conditions, rate and position of equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.