C6.3 The extraction of aluminium Flashcards
1
Q
Why is aluminum useful?
A
It has a low density but is very strong
2
Q
Why can you not use carbon to displace aluminum?
A
As it is more reactive than carbon
3
Q
Where can you get aluminum from?
A
Bauxite ore
4
Q
How can we save energy in the electrolysis of aluminium?
A
Add cryolite to lower the melting point
5
Q
What is the half equation at the cathode of the electrolysis of aluminium oxide?
A
Al+3(l) + 3e- → Al
6
Q
What is the half equation at the anode of the electrolysis of aluminium oxide?
A
2O-2 → O(2) molecule + 4e-
7
Q
Why do the electrodes need to be replaced at the anode?
A
Carbon reacts with oxygen to produce carbon dioxide
So the carbon electrode gradually burn off and need to be placed regulary
