Experiment: Purification of copper using electrolysis

Aim: To investigate the process of refining copper using electrolysis

Materials: two strips of copper, sandpaper, copper sulphate solution, 12 volt dc supply/battery, beaker, ammeter/bulb

Method

1. Clean two strips of copper using sandpaper
2. Place them in a solution of copper sulphate in a beaker
3. Set up the circuit as shown in the diagram above
4. Connect the electrodes to a battery
5. Allow the current to flow for five minutes
6. Carefully remove the electrodes from the solution and examine them

Observations and results

Electrolysis of copper. Image credit 180daysofteaching.wordpress.com

• The cathode/negative electrode becomes thicker as copper is deposited onto it
• The positive/anode electrode becomes thinner copper dissolves from it
• The colour of the copper sulphate solution remains the same
• as the copper taken from the copper sulphate solution at the negative electrode
• is replaced by copper dissolving into the solution at the positive side
• Any impurities in the copper at the positive side are left behind and fall into the solution

Conclusion

• Copper can be purified using electrolytic purification

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