During electrolysis. an electric current is passed through an electrolyte. The ions move towards the electrodes, where they react, and the compound decomposes
The positive ions move towards the cathode and gain electrons (reduced)
Negative ions in the electrolyte will move towards the anode and 10 se electrons (oxidised)
As ions gain or lose electrons, they form the uncharged element and are discharged from the electrolyte
Electrolysis of molten ionic solids forms elements
An ionic solid can't be electrolysed because the ions are in fixed positions and can't move
Molten ionic compounds can be electrolyted because the ions can move freely and conduct electricity
Extracting metals from their ores
Using electrolysis
Aluminum
Extracted from the ore bauxite by electrolysis
Aluminum oxide
Has a very high melting temperature
Mixed with Cryolite to lower the Melting point
Molten mixture
Contains free ions so it'll conduct electricity
Electrolysis of molten aluminum oxide
1. Positive Al 3+ ions are attracted to the negative electrode
2. They pick up three electrons and turn into neutral aluminium atoms
3. Neutral aluminium atoms sink to the bottom of the electrolysis tank
Electrolysis of molten aluminum oxide
1. Negative 02- ions are attracted to the positive electrode
2. They lose two electrons
3. Neutral oxygen atoms combine to form 0-2 Molecules
