This question is about electrolysis.
A student investigated the following hypothesis:
'The electrolysis of an aqueous salt solution produces a solid metal at the negative electrode and a gas at the positive electrode.'
What observation would be made at each electrode if the hypothesis is correct?
- Observation for solid metal at the negative electrode
- Observation for gas at the positive electrode
Table 1 shows the student's results.
Table 1
| Aqueous Salt Solution | Product at the negative electrode | Product at the positive electrode |
|---|---|---|
| Silver nitrate | Silver | Oxygen |
| Magnesium sulfate | Hydrogen | Oxygen |
| Copper(II) chloride | Copper | Chlorine |
Which salt solution in Table 1 does not support the student's hypothesis? Give a reason for your answer.
- Salt solution
- Reason
The electrodes used in this experiment are made of graphite. State two properties of graphite that make it suitable for this use.
A different student investigated the movement of ions during electrolysis using the apparatus shown in Figure 1.
The purple crystal contains:
- colourless positive ions
- purple-coloured negative ions.
The purple crystal dissolves in the electrolyte solution.
State and explain where the purple colour moves when the current is switched on.
- Movement of the purple colour
- Reason
Electrolysis Questions
Practise AQA GCSE Chemistry Electrolysis with exam-style questions for Foundation and Higher tier. 23 questions covering The process of electrolysis, Electrolysis of molten ionic compounds, Using electrolysis to extract metals, Electrolysis of aqueous solutions, and Representation of reactions at electrodes as half equations (HT only), matched to the AQA GCSE Chemistry (8462) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.