2. Properties of metals

3. Chemical properties Form oxides when they react with oxygen Metal oxides are bases Form positive ions Transition metals have a variable valency, for example iron can form ions of Fe 2+ or Fe 3+

4. Reactivity Reactions are caused by electrons moving from one atom to another How much energy is needed to gain or lose and electron is what changes the reactivity between elements If it loses electrons very easily, it is more reactive than some which loses electrons less easily. The same applies to gaining electrons

5. Experiment time Look at the reactivity of zinc, copper, magnesium and iron in dilute hydrochloric acid Why do they react? What changes how vigorous the reaction is?

6. The Reactivity Series Some metals are more reactive than others As each metal has different reactivity, it's important to know which ones are more reactive than others to determine their uses Normally, it's the unreactive metals we use more But then what about aluminium????

8. Reactivity series The reactivity series acts as a ‘league table’ showing which metals are more reactive and therefore will displace another in a reaction.

9. Displacement Sulfate Copper During a displacement reaction the metal in a compound is replaced with a more reactive metal to form a new compound. Zinc

10. Model 1 Like people compounds find some partners more attractive than others, and will ‘ditch’ one metal for another.

11. Model 2 In this model the non-metal part of the compound is like a footballer leaving his club for one higher up the league. CHELSEA LIVERPOOL COPPER ZINC SULFATE

12. Experiment The displacement reaction of magnesium and copper sulfate can be written as word and symbol equations. Magnesium + Copper Sulfate  Magnesium Sulfate + Copper Mg + CuSO 4  MgSO 4 + Cu

13. FeCl 3 +Mg CuSO 4 +Fe AgNO 3 + Cu Initial colours Metal: Metal: Metal: Solution: Solution: Solution: Final colours Metal: Metal: Metal: Solution: Solution: Solution: Pour FeSO 4, CuSO 4 and AgNO 3 solutions in three test tubes (about 4 ml). Insert a cut of Mg ribbon to FeCl 3, piece of iron in CuSO 4 and a cut of copper wire to AgNO 3 solutions. Record the observation, write and balance equations and conclude what the differences in reactivities are.

14. Experiment MetalObservations with salt solutionDisplacement reaction (Yes/No) Magnesium Iron Copper

15. 1. Zinc oxide + calcium  2. Magnesium + iron oxide  3. Zinc + tin oxide  4. Magnesium sulphate + Zinc  5. Calcium + copper oxide  6. Magnesium + iron sulphate  7. Tin oxide + Copper  8. Gold + copper oxide  REACTION NO REACTION REACTION NO REACTION

16. Metals in competition: Carbon Carbon is included because it can reduce oxides of metals below it on the series Eg. Magnesium oxide heated with carbon doesn’t change, but lead oxide heated with carbon becomes carbon dioxide and lead metal

17. Carbon Carbon is more reactive than some metals. It will reduce their oxides to form the metal It is the reducing agent

18. Metals and metal oxide Metals do the same to oxides of less reactive metals They reduce metals lower on the series

19. REDOX!!!!! Reduction is GAINING electrons It can also be thought of as losing oxygen

20. Copper oxide and iron

21. Thermal decomposition Some compounds break down easily when you heat them Reactive metals make very stable compounds so these don’t breakdown so easily

22. Using the series Thermite process (http://www.youtube.com/watch?v=5uxsFglz2ig)http://www.youtube.com/watch?v=5uxsFglz2ig Simple cells Sacrificial protection Galvanising

24. Starter LO: understand how to extract metals from their ores Metals and their uses

25. Extracting metals Metals play a very important role in our society. Building, planes, trains, cars, electronics, furniture and miles of miles of wiring are all made out of metals. It is essential, therefore, that we are able to get a continuous supply of them. LO: understand how to extract metals from their ores

26. Ores Gold, silver and platinum are the only metals that can be found in the ground in their native state. All other metals are found combined with other chemical elements, commonly oxygen. The metals have to extracted from these compounds before they can be used LO: understand how to extract metals from their ores

27. Extracting metals So you have your ore. Now what? How do you go about getting the nice, pure metal that is locked inside it? To extract the metal, you must use an element that is higher up the reactivity series. This will kick out the metal that YOU WANT, leaving you free to sell it on or use it. (Reduction of the metal!) LO: understand how to extract metals from their ores

28. For some, this means electrolysis Extracting metals

29. Extracting Iron Iron is an EXTREMELY important metal. It was a vital part of the industrial revolution that happened in Britain in the 1700s and 1800s, which allowed Britain to become the dominant superpower at the time. It is still widely used today to make buildings and bridges. What elements could we use to extract iron from its ore? LO: understand how to extract metals from their ores

30. Extracting Iron LO: understand how to extract metals from their ores

31. Extracting Iron

32. TASK Assemble the information around the room into the correct order. Make sure you write down any word equations that you see and leave space to write down the symbol equations. LO: understand how to extract metals from their ores

33. Extracting Iron Iron is usually found in an ore called Haematite. This is mainly Iron Oxide (Fe 2 O 3 ) and Silicon Dioxide (SiO 3 ). Silicon dioxide is better known as sand! LO: understand how to extract metals from their ores

34. Extracting Iron To extract iron from its ore, we use carbon. The carbon is in the form of a substance called coke, which is made from coal. It is almost pure carbon. LO: understand how to extract metals from their ores

35. Extracting Iron Limestone is also used when extracting iron to get rid of impurities from the iron ore. LO: understand how to extract metals from their ores

36. The Blast Furnace Iron ore (Haematite), Coke and Limestone are put into the top of the blast furnace. (Charge) Hot air blasted in at the bottom. LO: understand how to extract metals from their ores

37. The Blast Furnace The hot air causes the coke to oxidise and form carbon dioxide Carbon + oxygen  Carbon dioxide This is exothermic which helps to heat the furnace LO: understand how to extract metals from their ores

38. The Blast Furnace The carbon dioxide reacts with more carbon to form Carbon monoxide. The carbon dioxide is reduced This stage is endothermic LO: understand how to extract metals from their ores Carbon dioxide +Carbon  monoxide

39. Carbon monoxide reduces the iron oxide to iron and carbon dioxide The Blast Furnace

40. Removing impurities The limestone is heated up in the blast furnace and decomposes into calcium oxide. The calcium oxide is needed to remove the sand from the ore LO: understand how to extract metals from their ores Calcium Carbonate  Calcium Oxide Carbon dioxide +

41. Removing impurities The calcium oxide reacts with the silicon dioxide impurities to make calcium silicate. LO: understand how to extract metals from their ores  Calcium Oxide Silicon Dioxide + Calcium Silicate Calcium silicate is better known as slag and is used to surface roads.

42. The Blast Furnace The ‘slag’ and the molten iron collect at the bottom, which can then be tapped off. LO: understand how to extract metals from their ores

43. Write out any equations you find! Round the class in pairs to put the process in the correct order

44. Task: Match the sentences LO: understand how to extract metals from their ores

45. Aluminium LO: understand the extraction of copper Aluminium is a very useful metal. It is light, easily shaped and does not react easily. However, it is above carbon in the reactivity series? Can aluminium be extracted using carbon?

46. Aluminium LO: understand the extraction of copper As aluminium is ABOVE carbon in the reactivity series, it can’t be extracted using carbon as iron is. Another process called electrolysis must be used. In electrolysis, electricity is passed through molten aluminium oxide and it separates into aluminium and oxygen. Why do you think this is more expensive than using carbon?

47. Aluminium's main ore is bauxite Aluminium

48. Step 1 – testing to see if there is enough aluminium for the extraction to be worthwhile Step 2 – After the ore is mined, the impurities are removed, leaving aluminium oxide Step 3 – The alumina is then sent away for electrolysis Step 4 – The metal is made into sheets and blocks Aluminium

50. Aluminium is released at the cathode. Aluminium ions are reduced by gaining 3 electrons. Al 3+ (l)+ 3e - Al (l) (reduction) Aluminium

51. Oxygen is produced initially at the anode. 2O 2- (l) 3O 2 (g) + 4e - (oxidation) Aluminium

52. Overall: 2Al 2 O 3 (l) 4Al (l) + 3O 2

53. As the oxygen gas bubbles of, it reacts with the carbon from the anode to release carbon dioxide This means the anode has to be changed regularly as it gets eaten away C (s) + O 2(g) CO 2(g) Aluminium

54. Zinc blende is mostly zinc sulfide and must be roasted in air to form ZnO and sulfur dioxide Then the oxide can be reduced in one of two ways 1. Using carbon monoxide 2. Using electrolysis Zinc Extraction

55. Carbon monoxide – after the reaction carbon dioxide is given off leaving zinc with some impurities. These are seperated using fractional distillation Using electrolysis – It’s dissolved in sulphuric acid (metal oxide + acid), leaving a salt that can be separated by electrolysis Zinc Extraction

56. Remembering the series

57. Task LO: understand the extraction of copper Re-using and recycling aluminium

58. Using metals The properties of the metal dictate it’s uses Eg. Copper, aluminium, gold etc.

60. What is an alloy?

61. Most pure metals are not very useful. They must be mixed with other substances before they can be used to their full extent! A metal that contains another element is called an alloy. One of the most commonly used alloys is steel. Steel is a mixture of Iron and Carbon. LO: understand the structure and uses of alloys

62. What is an alloy? LO: understand the structure and uses of alloys

63. What is an alloy? LO: understand the structure and uses of alloys

64. Alloys Alloys are metals consisting of more than 1 element A mixture of two elements where one of which is a metal! Alloys contain atoms of different sizes, which distorts the regular arrangements of atoms. This makes it more difficult for the layers to slide over each other, so alloys are harder than the pure metal.

65. Different Alloys Brass – Copper and zinc Bronze – Copper and tin Solder – lead and tin

67. Steel Steel is stronger than pure iron Mild steel – 99.7% iron, 0.3% carbon Stainless steel 70% iron, 20% chromium, 10% nickel