extraction of aluminium Flashcards
1
Q
what is bauxite
A
you get aluminium from the core of bauxite by open cast mining
2
Q
why does aluminium contain cryolite
A
aluminium oxide is dissolved in cryolite to lower its melting point. this saves money on energy costs
3
Q
what is graphite
A
electrodes r made from graphite (carbon) as graphite can conduct electricity
4
Q
why can graphite conduct electricity
A
because it has delocalised electrons between its layers.
5
Q
what happens when positive Al3+ ions move to the cathode
A
aluminium is produced by reduction
6
Q
whats the formula for aluminium reduction at the cathode
A
Al3+ + 3e -> Al
7
Q
what happens when negative O2- ions move to the anode
A
oxygen is formed by oxidation
8
Q
whats the formula for oxygen formed by oxidation
A
2O2- -> 02 + 4e-
