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Reactivity and the_reactions_of_metals
- 1. © Boardworks Ltd20081 of 53
- 2. © Boardworks Ltd20082 of 53
- 3. © Boardworks Ltd20083 of 53 Reacting metals with oxygen Most metals react with oxygen. Some metals react quickly and some only react very slowly. Magnesium, for example, burns in oxygen with a bright flame. When a metal reacts with oxygen, the product is a metal oxide. This is called an oxidation reaction. metal oxygen metal oxide+
- 4. © Boardworks Ltd20084 of 53 Investigating reactivity with oxygen
- 5. © Boardworks Ltd20085 of 53 Order of reactivity with oxygen
- 6. © Boardworks Ltd20086 of 53 Equations: reactions of metals with oxygen What is the balanced symbol equation for each reaction? 4Fe O2 2Fe2O3+ iron oxygen iron oxide+ 2Cu O2 2CuO+ + oxygen copper oxidecopper 2Mg O2 2MgO+ magnesium oxygen magnesium oxide+
- 7. © Boardworks Ltd20087 of 53 What happens to the mass?
- 8. © Boardworks Ltd20088 of 53 Metals and oxygen: true or false?
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- 10. © Boardworks Ltd200810 of 53 Metals and water The Romans used lead to make water pipes but didn’t know that lead reacts slowly with water and makes it poisonous! Some metals react vigorously with water, some metals react slowly and some do not react at all. Which is the best type of metal to use for water pipes?
- 11. © Boardworks Ltd200811 of 53 Using unreactive metals The words ‘plumber’ and ‘plumbing’ come from plumbum (the Latin word for lead) because the ancient Romans used lead for their water pipes. Why is lead no longer used in plumbing? Copper is a much better metal for water pipes because it does not react at all with water – perhaps plumbers should be renamed coppers!
- 12. © Boardworks Ltd200812 of 53 Reacting metals with water When any metal reacts with water, the products are a metal hydroxide and hydrogen gas. What tests could you do to show that hydrogen and a hydroxide have been produced? metal water metal hydroxide hydrogen+ + This is the general equation for the reaction of a metal with water:
- 13. © Boardworks Ltd200813 of 53 Investigating reactivity with water (I)
- 14. © Boardworks Ltd200814 of 53 Equations: reactions of metals with water What is the balanced symbol equation for each reaction? 2Na 2H2O 2NaOH H2+ + sodium water sodium hydroxide hydrogen+ + 2Li 2H2O 2LiOH H2+ + + water lithium hydroxide hydrogenlithium + 2K 2H2O 2KOH H2+ + potassium water potassium hydroxide hydrogen+ +
- 15. © Boardworks Ltd200815 of 53 Investigating reactivity with water (II) James investigated how reactive some metals were with water. He made these observations: reacts slowly with cold water but reacts quickly with steamgold metal reaction with water calcium no reaction no reactionsilver zinc no reaction Copper is used in plumbing and silver and gold in jewellery. Why are these unreactive metals suitable for such uses?
- 16. © Boardworks Ltd200816 of 53 Order of reactivity with water
- 17. © Boardworks Ltd200817 of 53 Odd one out
- 18. © Boardworks Ltd200818 of 53
- 19. © Boardworks Ltd200819 of 53 Corrosion of metals Metals corrode when they are left in contact with air or water. Which metals corrode quickly and which corrode slowly? When iron corrodes, it is called rusting. Rusting is the oxidation reaction of iron with oxygen in the presence of water. oxygen iron oxideiron + 3O2 Fe2O32Fe +
- 20. © Boardworks Ltd200820 of 53 Does salt make iron rust faster? People who live by the seaside often claim that their cars go rusty faster. Does salt speed up the rate of the rusting reaction?
- 21. © Boardworks Ltd200821 of 53 What is needed for iron to rust?
- 22. © Boardworks Ltd200822 of 53 Preventing rust Rusting destroys a huge amount of iron and steel every day. People spend a lot of money making sure that their iron and steel buildings, engines, lorries and ships do not rust. What methods could you use to prevent things rusting? painting plastic coating oilinggalvanising
- 23. © Boardworks Ltd200823 of 53 Rusting: sacrificial protection Sacrificial protection is another way of preventing rust. This involves attaching big blocks of magnesium or zinc to the iron hull of a ship or water pipe. Because magnesium is more reactive than iron, it corrodes first, leaving the iron intact. Eventually the magnesium blocks have to be replaced because they have corroded completely away. iron reactive metal
- 24. © Boardworks Ltd200824 of 53 Rusting: true or false?
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- 26. © Boardworks Ltd200826 of 53 Reacting metals with acid
- 27. © Boardworks Ltd200827 of 53 Order of reactivity with acid
- 28. © Boardworks Ltd200828 of 53 This list is called the reactivity series. The more reactive the metal, the more vigorous the reaction. Metals can be listed in order of how reactive they are. A metal that is below hydrogen will not react with dilute acids. increasingreactivity Reactivity of metals calcium sodium copper hydrogen lead iron zinc aluminium magnesium
- 29. © Boardworks Ltd200829 of 53 Products of metal reacting with acid When metals react with acid, bubbles of gas are produced. The ‘squeaky pop’ test shows that this gas is hydrogen. When a metal reacts with acid, the products are hydrogen gas and a metal salt. What is the general equation for the reaction of a metal with acid? metal acid metal salt hydrogen+ +
- 30. © Boardworks Ltd200830 of 53 Metals and hydrochloric acid – equations What is the balanced symbol equation for each reaction? hydrochloric acid magnesium chloride magnesium hydrogen+ + Mg 2HCl MgCl2 H2+ + aluminium hydrochloric acid aluminium chloride hydrogen+ + 2Al 6HCl 2AlCl3 3H2+ + zinc hydrochloric acid zinc chloride hydrogen+ + Zn 2HCl ZnCl2 H2+ +
- 31. © Boardworks Ltd200831 of 53 Reaction of metals with acids When a metal reacts with an acid, the products are a salt and hydrogen gas. metal acid salt hydrogen+ + The salt produced depends on the metal and type of acid involved in the reaction: When a metal reacts with hydrochloric acid, the salt produced is a metal chloride. When a metal reacts with sulfuric acid, the salt produced is a metal sulfate. When a metal reacts with nitric acid, the salt produced is a metal nitrate.
- 32. © Boardworks Ltd200832 of 53 What is the equation?
- 33. © Boardworks Ltd200833 of 53 Word equations for metals and acids
- 34. © Boardworks Ltd200834 of 53 Balancing equations for metals and acids
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- 36. © Boardworks Ltd200836 of 53 Comparing reactivity The orders of reactivity of metals with water, oxygen and air can be compared. with water lithium copper gold sodium magnesium silver potassium with oxygen zinc lead magnesium iron copper calcium with acid aluminium iron copper magnesium zinc lead calcium What patterns can you see in these lists?
- 37. © Boardworks Ltd200837 of 53 The reactivity series Combining the information from all the reactions gives an overall order of reactivity called the reactivity series. One way to remember this order is to learn this silly sentence: please send charlie’s monkeys and zebras in large cages securely guarded!
- 38. © Boardworks Ltd200838 of 53 What is the order of reactivity?
- 39. © Boardworks Ltd200839 of 53 Using the reactivity series The reactivity series can be used to make predictions about the reactions of metals. Predictions can be made about simple reactions of metals with oxygen, water and acids. Predictions can also be made about more complex reactions where one metal is competing with another. potassium sodium calcium magnesium aluminium zinc iron lead copper silver gold increasingreactivity
- 40. © Boardworks Ltd200840 of 53 Predicting simple reactions Use the reactivity series to predict if a reaction will take place and how intense the reaction will be: acidgold metal reacts with calcium sodium oxygen oxygen oxygensilver prediction zinc water no reaction fizzing burns vigorously very slow reaction burns moderately
- 41. © Boardworks Ltd200841 of 53 oxygen in the atmosphere coating of oxygen atoms aluminium atoms Aluminium According to the reactivity series, aluminium should be a fairly reactive metal, but in reality it often appears unreactive. Why? This is because a protective layer of aluminium oxide quickly forms on its surface, which stops it reacting. This means aluminium can be used to build aeroplanes and saucepans. However, if the protective layer is removed, the aluminium reacts more quickly.
- 42. © Boardworks Ltd200842 of 53 The reactivity series: summary
- 43. © Boardworks Ltd200843 of 53 What is a displacement reaction? The Thermit reaction is an example of a displacement reaction. The more reactive aluminium takes the oxygen from the less reactive iron. The reaction gets so hot that the iron melts! It is used to weld railway tracks. aluminium iron oxide iron+ aluminium oxide + In this reaction, aluminium reacts with iron oxide to make aluminium oxide and iron.
- 44. © Boardworks Ltd200844 of 53 Displacement in action What happens when magnesium reacts with copper sulfate? magnesium copper sulfate copper+ magnesium sulfate + Magnesium is a more reactive metal than copper and so the magnesium displaces the copper from the copper sulfate solution. This is why the blue colour disappears. Why does the blue colour of the copper sulfate solution gradually disappear during this reaction? before after
- 45. © Boardworks Ltd200845 of 53 Explaining displacement reactions The reactivity series can be used to predict if a metal will react with a metal compound. If the metal is more reactive than the metal in the compound, it pushes out, or displaces, the less reactive metal from its compound. If the metal is less reactive than the metal in the compound, it will not compete and so there is no reaction. more reactive metal less reactive metal compound more reactive metal compound less reactive metal + + less reactive metal more reactive metal compound no reaction +
- 46. © Boardworks Ltd200846 of 53 Displacement reactions – examples Will magnesium react with copper chloride? Magnesium is a more reactive metal than copper, so magnesium displaces the copper from its compound. Will silver react with magnesium chloride? Silver is a less reactive metal than magnesium, so silver does not displace the magnesium from its compound. magnesium copper chloride copper+ magnesium chloride + magnesium chloride + no reactionsilver
- 47. © Boardworks Ltd200847 of 53 Displacement in extracting metals Displacement reactions can be used to extract metals from their ores. For example, iron and copper are extracted from their oxides by reacting the ores with carbon: iron oxide carbon carbon dioxide iron+ + copper oxide carbon carbon dioxide copper+ +
- 48. © Boardworks Ltd200848 of 53 Displacement reactions – activity
- 49. © Boardworks Ltd200849 of 53 Displacement reactions Use the reactivity series to predict if each mixture will react and complete the word equation. magnesium aluminium oxide + magnesium oxide aluminium+ iron chloride magnesium + magnesium chloride iron+ copper gold nitrate+ copper nitrate gold+ silver zinc oxide no reaction+
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- 51. © Boardworks Ltd200851 of 53 Glossary
- 52. © Boardworks Ltd200852 of 53 Anagrams
- 53. © Boardworks Ltd200853 of 53 Multiple-choice quiz