Metal Extraction
Chemistry: AQA GCSE Higher, topic 4.4.3
Electrolysis - Extracting Metals
Electrolysis is used to extract reactive metals from molten ores (melted materials containing metals). Electrolysis is used to extract metals such as aluminium, which are higher in the reactivity series than carbon.
What happens at the anode?
- Oxygen forms at the carbon anode. The carbon and oxygen react to give carbon dioxide.
- The anode is usually made of carbon because it is a good conductor and is cheap.
What happens at the cathode?
- The aluminium is formed at the cathode.
What are the disadvantages of electrolysis?
- Lots of energy is needed to:
- Melt the solid ionic compound to allow the ions to flow.
- Produce the electrical current.
- All this energy costs money, and a lot of it!
Test yourself on Metal Extraction
Why does electrolysis need such large amounts of energy?
Why does electrolysis cost a lot of money to carry out?
Why is the anode used in electrolysis usually made of carbon?
Why does carbon dioxide form at the anode during the electrolysis of aluminium ore?