This document discusses the uses of electrolysis in industries, including the purification of metals, electroplating of metals, and extraction of metals. It provides examples of how electrolysis is used to purify copper, electroplate metals like tin onto cans, and extract reactive metals like aluminum from ores. The document also notes some of the potential pollution problems caused by electrolysis in industry, such as releasing heavy metals and altering the pH of water resources.

1. 4S4 08 July 2010
Electrolysis in industries
Purification of metals
Electroplating of metals
Extraction of metals

2. Learning outcomes
At the end of the lesson, you should able to:
• state uses of electrolysis in industries,
• explain the extraction, purification and
electroplating of metals involving electrolysis in
industries,
• write chemical equations to represent the
electrolysis process in industries,
• justify uses of electrolysis in industries,
• describe the problem of pollution from
electrolysis in industry.

3. 200 million yen ($1817,355)

4. Pure copper

5. Purification Of Copper

7. Electroplating of metals

9. References-Video clip
• Gold, Silver & Chrome Plating Before & After
Pics.
http://www.youtube.com/watch?v=GQS4Tg9
2WmM&feature=related

10. Electroplating of metals

11. Cu → Cu2+ + 2e- Cu2+ + 2e- → Cu

12. Tin Can
Sn
• Expensive
• Very thin coating (<0.0005 mm thick)

13. Extraction of metals
• Reactive metals : Al, Mg, Na
• Extracted from ores by electrolysis
• Electrolysis of Molten compounds /
concentrated solutions o salts / hydroxide
solutions
• Cathode: Metals formed

14. Extraction of ALUMINIUM
• Extracted from ores, ALUMINIUM OXIDE, Al2O3
• Electrolyte: Molten aluminium oxide, Al2O3
• + CRYOLITE, Na3AlF6
(to Lower the melting point)
• Cathode: Aluminium, Al Metals formed

15. Extraction of aluminium

16. Uses of ALUMINIUM
• kitchen utensils,
• exterior decorations
• thousands of industrial applications
• ALLOYS OF ALUMINUM
• = Duranium (Al+Cu+Mg+Mn)
-used in aircraft, bullet train.

17. Recycling ALUMINIUM
• Saves 91 % energy
• From extraction of Al
from bauxite

18. Effects of the uses of electrolysis
in industries
• Pollution
• Poisonous heavy metal ions , cyanide ions
• Eg.: aluminum, arsenic, cadmium, lead, and
mercury,…
• Effects? Nervous system
• Waste chemicals – alter pH of water
resources