The electrolysis of other molten substances
3 marks · EasyA student studies the electrolysis of three molten ionic compounds.
| Compound | Element at Cathode | Element at Anode |
|---|---|---|
| Magnesium fluoride | ? | Fluorine |
| Lead(II) bromide | Lead | ? |
| Potassium iodide | ? | Iodine |
(a)[1 mark]
Complete the table by naming the element formed at the cathode for magnesium fluoride.
(b)[1 mark]
Name the element formed at the anode for lead(II) bromide.
(c)[1 mark]
Name the element formed at the cathode for potassium iodide.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) Magnesium
(b) Bromine
(c) Potassium
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Gives 'magnesium' as the element at the cathode for magnesium fluoride.
B2 (b) · 1 mark · Gives 'bromine' as the element at the anode for lead(II) bromide.
B3 (c) · 1 mark · Gives 'potassium' as the element at the cathode for potassium iodide.
Worked solution
| Compound | Element at Cathode | Element at Anode |
|---|---|---|
| Magnesium fluoride | Magnesium | Fluorine |
| Lead(II) bromide | Lead | Bromine |
| Potassium iodide | Potassium | Iodine |