Getting Metals from Rocks 2 Flashcards
Metals more reactive than carbon =
Have to be extracted using electrolysis of molten compounds.
Give an example of a metal which has to be extracted by electrolysis?
Aluminium.
Why is the process of electrolysis expensive?
It uses a lot of energy.
How is extracted aluminium expensive?
A high temperature is needed to melt aluminium oxide so that aluminium can be extracted .
Requires a lot of energy- expensive.
What metal is purified by electrolysis?
Copper.
What can copper easily do?
Be extracted by reduction with carbon.
Where is copper heated?
In a furnace.
What is heating in a furnace called?
Smelting.
However, copper produced by smelting is what?
Impure.
What doesn’t impure copper do?
Conduct electricity very well.
Isn’t useful as copper is used to make electrical wiring.
What is used to purify impure metals?
Electrolysis.
Quite expensive.
What does electrolysis produce?
Very pure metal.
Eg copper and its a good conductor.
What does electrolysis mean?
Breaking down of a substance using electricity.
What does electrolysis require?
Liquid to conduct the electricity, called the electrolyte.
What is an electrolyte?
Metal salt solutions made from the ore or molten metal oxides.
What does the electrolyte have?
Free ions.
What does the electrolytes fee ions do?
Conduct electricity and allow the whole thing to work.
What happens to the electrons?
Taken away from the positive anode and given away by the negative cathode
What happens when ions gain or lose electrons?
They become atoms or molecules and are released.
How is electrolysis used to get copper?
Electrons are pulled off copper atoms at the anode, causing them to go into the solution as Cu2+ ions.
Cu2+ ions near the cathode gain electrons and turn back into copper atoms.
The impurities are dropped at the anode as a sludge, whilst pure copper atoms bond to the cathode.
COPPER;
What is released into the solution?
Cu2+.
COPPER;
What do the Cu2+ ions near the cathode do?
Gain electrons and turn back into copper atoms.
COPPER;
Where do the pure copper atoms go?
Bond to the cathode.
COPPER;
What does the cathode start as?
A think piece of pure copper.
More pure copper adds to it.
COPPER;
What is the anode?
Big lump of impure copper which will dissolve.
