Purification of copper

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Purification of copper

• The use of electrolysis

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Why?

• Copper extraction is expensive

• Recycling is good for the environment

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The Apparatus
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What happens at the cathode?

• Positive copper ions are in solution

• The copper is attracted to the cathode

• The copper ions gain electrons at the cathode to
  become copper atoms

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The chemistry

• Cu2 2e- ---gt Cu

The copper ions have gained electrons
We say the copper has been reduced
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• O
• I
• L
• R
• I
• G

XIDATION
S
OSS
OF ELECTRONS
EDUCTION
S
AIN
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What happens at the anode?

• Cu ---gt Cu2 2e-

• The copper ions lose electrons

• The copper atoms are oxidised to ions

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The apparatus
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Conclusion

• The pure copper electrodes size increases

• The impure copper electrodes size decreases

The mass of the copper lost by the anode
The mass of the copper gained by the cathode