extraction of aluminum Flashcards
1
Q
what is bauxite
A
(aluminium with impurities)
-> is purified by alkaline
-> into pure aluminium oxide (Al2O3)
2
Q
why is Al2O3 is mixed with molten cryolite before the extraction can occur
A
lower the melting point, without interfering with the reaction itself
-> save money
3
Q
how to extract aluminum
A
electrolysis
- cathode - graphite
- anode - graphite
4
Q
what happen at the cathode
A
Al(3+) + 3(e–) → Al
(reduction – gain electrons)
5
Q
why is anode get replace frequently
A
this oxygen reacts with the carbon of the positive electrodes, forming carbon dioxide, -> so they gradually burn away.
6
Q
what happen at the anode
A
2O(2–) → O2 + 4e(–)
(oxidation – lose electrons)
