GCSE Chemistry Required Practical: Electrolysis of a Solution
Contents
Key Stage 4
Meaning
Perform an electrolysis experiment to observe what happens when an aqueous solution is electrolysed.
Method
- Pour 50ml of Copper (II) Chloride solution into a 100ml beaker.
- Place two Carbon electrodes held apart from one another by an electrical insulator.
- Attach a direct current power pack to the electrodes using wires and crocodile clips.
- Set the potential difference to 4 Volts.
- Record your observations of changes at each electrode. You may also use a pH Indicator paper next to the anode but above the solution and note any colour change.
- After 5 minutes turn off the power pack and remove the cathode to observe whether any changes have taken place.
- Repeat this experiment for the following solutions; Copper (II) Sulphate, Sodium Chloride and Sodium Sulphate.
Copper Chloride Results
- Anode: Bubbles of gas form - Placing litmus paper next to the anode bleaches the paper, showing the presence of Chlorine gas.
- Cathode: A pink/brown solid forms. - This is copper.
Copper Sulphate Results
- Anode: Bubbles of gas form - Collecting the gas in a test tube it relights a glowing splint, showing the presence of Oxygen.
- Cathode: A pink/brown solid forms - This is copper.
Sodium Chloride Results
- Anode: Bubbles of gas form - Placing litmus paper next to the anode bleaches the paper, showing the presence of Chlorine gas.
- Cathode: Bubbles of gas form - Collecting the gas in a test tube a lit splint causes a squeaky pop sound, showing the presence of Hydrogen gas.