11.1.2

Extracting Metals - Electrolysis

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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.

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Process

  • Powdered aluminium ore (Al2O3) is first mixed with another aluminium salt called cryolite.
  • This mixture has a lower melting point than pure Al2O3. This makes it cheaper as less energy is needed to melt the powder.
  • Once molten, a large voltage is applied.
Illustrative background for What happens at the cathode?Illustrative background for What happens at the cathode? ?? "content

What happens at the cathode?

  • The aluminium is formed at the cathode.
Illustrative background for What happens at the anode?Illustrative background for What happens at the anode? ?? "content

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.
Illustrative background for What are the disadvantages of electrolysis?Illustrative background for What are the disadvantages of electrolysis? ?? "content

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!

Jump to other topics

1States of Matter

2Elements, Compounds & Mixtures

3Atomic Structure

4The Periodic Table

5Chemical Formulae, Equations & Calculations

6Bonding

7Electrolysis

8Groups of the Periodic Table

9The Atmosphere

10Reactivity Series

11Metal Extraction

12Acids & Alkalis

13Chemical Tests

14Physical Chemistry

15Organic Chemistry

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