1. Reactions of Metals

2. Metal Oxides Salts and hydrogen React with oxygen to giveReact with acids to give

3. Example of Metal Reactions Iron Iron is moderately reactive. It will react with steam or acids to displace Hydrogen Fe + 2HCl FeCl 2 + H 2 Copper Is one of the least reactive metals. Does not react with dilute acid If the metal is heated in air a black layer of copper oxide is formed. 2Cu + O 2 2CuO

4. Example of Metal Reactions Copper statues and roofs become coated with a green layer of copper (II) carbonate. Copper carbonate will decompose on heating to release carbon dioxide. CuCO 3 CuO + CO 2

5. Tests for Copper Compounds of copper give a blue green flame. Solutions of copper salts give a gelatinous precipitate of copper hydroxide if sodium hydroxide is added. If the precipitate is heated it will turn black as it is unstable and it is converted to copper oxide. Ammonia solutions will also produce the same precipitate but will re- dissolve on adding excess solution.

6. Example of Metal Reactions Zinc Zinc is a moderately reactive metal. It will displace hydrogen from steam or dilute acids. Zn + H 2 O ZnO H 2 Zn + 2HCl ZnCl 2 + H 2

7. Example of Metal Reactions Zinc carbonate decomposes on heating to give off carbon dioxide ZnCO 3 ZnO + CO 2

8. Reactivitly of Metals

9. Reactivity of Metals Most elements in the periodic table are metals. Reactivity changes in particular groups. Reactivity: Reactivity is determined by investigating the following for a metal; – Ease of extraction – Reaction with oxygen – Reaction with water – Reaction with dilute acids – Metal displacement in redox reactions – Heat stability

10. Reactivity Series Extraction Techniques Electrolysis of molten ores Reduction of oxides with carbon Occur native in the ground

12. Metal Displacement Reaction Use it to compare the reactivity of two metals. A more reactive metal displaces a less reactive metal. The metals are in direct competition.

13. Displacement Reaction Zinc displaces copper from solution so zinc is more reactive than copper. Zn + CuSO 4 ZnSO 4 + Cu

14. Redox Reactions Aluminium, the more reactive metal, removes oxygen from the less reactive iron. Fe 2 O 3 + 2Al Al 2 O 3 + 2Fe

15. Activity Questions of page 239 and 244 Exam style questions on page 246