7. 6. As electrolyte in car batteries 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
8. 7. Remove oxides from the surface of metals (metallurgy 冶金学) 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
9. CONTACT Process Manufacture of sulphuric acid 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
10. The Manufacture of H2SO4, through the Contact Process 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
11. Contact Process: Stage 1 In the furnace, molten sulphur is burnt in dry air to produce sulphur dioxide, SO2. The gas produced is purified and cooled. S(l) + O2(g) SO2(g) 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
12. Contact Process: Stage 2 In the converter, SO2 and excess oxygen gas, O2 are passed over a few plates of vanadium (V) oxide, V2O5 catalyst at 450oC to produce sulphur trioxide, SO3 2SO2(l) + O2(g) 2SO3(g) 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
13. Contact Process: Stage 2 About 99.5% of the sulphur dioxide, SO2 is converted into sulphur trioxide, SO3 through this reversible reaction. 2SO2(l) + O2(g) 2SO3(g) 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
14. Contact Process: Stage 3 In the absorber, the sulphur trioxide, SO3 is first reacted with concentrated sulphuric acid, H2SO4 to form a product called oleum, H2S2O7. SO3(g) + H2SO4(l) H2S2O7(l) 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
15. Contact Process: Stage 3 The oleum, H2S2O7 is then diluted with water to produce concentrated sulphuric acid, H2SO4 in large quantities. H2S2O7(l)+ H2O(l) 2H2SO4(l) 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
16.
17.
18. The mist is corrosive, pollutes the air and is difficult to condense17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
19. FAQ 2 Why don’t we increase the pressure in the converter? So we can produce more sulphur trioxide per day? 2SO2(l) + O2(g) 2SO3(g) Answer: Yes, high pressure increases the rate of reaction, but it cost very high also. So, the reaction is done at pressure close to atmospheric pressure. 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
21. Sulphur dioxide and environmental pollution 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
22. Sulphur dioxide, SO2 Source: By-products of the contact process Burning of fossil fuels containing sulphur 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
24. Ammonia nh3 and its salt 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
25. 1. Manufacture of fertilisers 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
26. 2. Manufacture of synthetic fibers 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
27. 3. Manufacture of explosives 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
28. Haber process Manufacture of Ammonia 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
29. The Manufacture of Ammonia, NH3 through the Haber Process Ratio 1:3 N2(g) + 3H2(g) 2NH3(g) 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
31. Metals are Ductile/Can be stretched (可延展的) The orderly arrangement of atoms in metals enables the layers of atoms to slide on another when force is applied 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
32. Metals are Malleable There are some inperfections in the orderly arrangement of atoms in metals that allow some empty space in between the atoms. When a metal is knocked, atoms slide. 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
33. Alloy Definition: A mixture of two or more elements with a certain fixed composition in which the major component is a metal. Properties of pure metals can be improved => stronger, harder, resistant to sorrosion, have a better furnish and lustre. 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)
34. GOLD (24K, 18K) Pure gold 24K (24-carat) 18K Gold has 18 parts of gold and 6 parts of other metals 17/5/2010 rebeccachoong@gmail.com 4S8 Chemistry, Catholic High School, PJ (2010)