Metals & Alloys Flashcards
How do you get copper from its ore?
Heat it with carbon, process is called smelting.
The copper is reduced, what does this mean?
It is the removal of oxygen from a substance
How do you purify impure copper?
Electrolysis
Which is cheaper, making or recycling copper?
Recycling saves resources, uses less energy.
What are the electrodes called in electrolysis?
Positive Anode, negative cathode
What is the liquid called?
The electrolyte,
What are the advantages of copper recycling?
Makes un-mined copper resources last longer
Reduces costs of manufacture
Reduces landfill
Reduces environmental damage from copper mining Saves energy.
What are the disadvantages of copper recycling?
Copper is often stolen to sell for scrap, if cables are stolen this can cause problems with trains or electrical supply or motorway signalling.
In the purification of copper by electrolysis, what are the electrodes made of?
Both are made of copper, the anode is impure copper but the cathode is pure copper
What is the liquid/solution used?
Copper (II) sulphate solution is the electrolyte.
What happens at the anode?
The Anode loses mass as copper atoms dissolve and become ions. Anode Slime forms.
What happens at the cathode?
The cathode gains mass as the copper ions are deposited as copper atoms
Explain the changes at the anode
Copper atoms lose 2 electrons to the external circuit and become copper 2+ ions
Cu(s) – 2e –-> Cu2+
Oxidation because electrons are lost. OIL
Explain the changes at the cathode
Copper 2+ ions gain 2 electrons from the external circuit and become copper atoms
Cu2+ 2e– —>Cu(s)
Reduction because electrons are gained. RIG
What is Anode Slime?
When the copper atoms leave the anode the impurities fall to the bottom of the cell. Impurities like gold, silver and platinum!
