1. Do now! Can you read through the blast furnace equations?

2. Last lesson The reduction of copper oxide using carbon.

3. Extracting copper from copper oxide 2CuO + C 2Cu + CO 2

4. Today’s lesson The extraction of aluminium from aluminium oxide (Bauxite)

5. Reactivity Series

6. Electrolysis of aluminium oxide CO 2

7. Electrolysis of aluminium oxide Aluminium oxide has a high melting point (2054°C) (EXPENSIVE)

8. Electrolysis of aluminium oxide Aluminium oxide will dissolve in molten cryolite which melts at “only” 959°C (CHEAPER)

9. Electrolysis of aluminium oxide The molten liquid is put into a large chamber, the walls of which are connected to the negative side of a circuit (cathode). Large positive electrodes (anodes) made of graphite are lowered into the mixture.

10. Electrolysis of aluminium oxide Aluminum oxide is an ionic compound. The positive aluminium ions drift to the negative electrode (cathode) and the negative oxygen ions to the positive electrodes (anodes).

11. Electrolysis of aluminium oxide At the cathode the aluminium ions gain electrons and become aluminium atoms. 4Al 3+ + 12e - 4Al

12. Electrolysis of aluminium oxide At the anodes the oxygen ions lose electrons and become oxygen atoms. 6O 2- 3O 2 + 12e -

13. Electrolysis of aluminium oxide The oxygen immediately reacts with the hot graphite to form carbon dioxide. This means the graphite electrodes have to be replaced occasionally as they wear away.

14. Electrolysis of aluminium oxide Molten aluminium is tapped from the bottom of the chamber

15. Electrolysis of aluminium oxide This all requires LOTS of electricity so is an expensive process.

16. Electrolysis of Aluminium Aluminium oxide has a high melting point (2054°C) (EXPENSIVE) Aluminium oxide will dissolve in molten cryolite which melts at “only” 959°C (CHEAPER) The molten liquid is put into a large chamber, the walls of which are connected to the negative side of a circuit (cathode). Large positive electrodes (anodes) made of graphite are lowered into the mixture. Aluminum oxide is an ionic compound. The positive aluminium ions drift to the negative electrode (cathode) and the negative oxygen ions to the positive electrodes (anodes). At the cathode the aluminium ions gain electrons and become aluminium atoms. 4Al 3+ + 12e-4Al At the anodes the oxygen ions lose electrons and become oxygen atoms. 6O 2- 3O 2 + 12e- The oxygen immediately reacts with the hot graphite to form carbon dioxide. This means the graphite electrodes have to be replaced occasionally as they wear away. Molten aluminium is tapped from the bottom of the chamber Maximum two words per drawing - numbers allowed

17. Homework Can you complete the “Draw the sentence” exercise for Wednesday 23 rd September?