Metals ppt

21,663 views
21,145 views

Published on

Published in: Education, Business, Technology
2 Comments
23 Likes
Statistics
Notes
No Downloads
Views
Total views
21,663
On SlideShare
0
From Embeds
0
Number of Embeds
106
Actions
Shares
0
Downloads
0
Comments
2
Likes
23
Embeds 0
No embeds

No notes for slide

Metals ppt

  1. 1. Metals W Richards Worthing High School
  2. 2. Periodic table Horizontal rows are called PERIODS Mendeleev The periodic table arranges all the elements in groups according to their properties. Vertical columns are called GROUPS
  3. 3. What does the periodic table tell you? The SYMBOL of the element The NAME of the element The PROTON NUMBER of the element Au Gold 79
  4. 4. Group 1 – The alkali metals Fr Cs Rb K Na Li
  5. 5. Group 1 – The alkali metals 1) These metals all have to be stored under ____ because they react with _______ Some facts… 2) Reactivity increases as you go _______ the group. This is because the electrons are further away from the _______ every time a _____ is added, so they are given up more easily. 3) They all react with water to form an alkali (hence their name) and __________, e.g: Words – down, oil, shell, hydrogen, nucleus, water Potassium + water potassium hydroxide + hydrogen
  6. 6. The Transition Metals 1) This section includes metals like gold, mercury, iron, copper Some facts… 2) They are all ______ and solid (except _________) 3) They are ____ reactive than the alkali metals Words – hard, coloured, mercury, less 4) They can form __________ compounds
  7. 7. Some common symbols… Lithium Li Sodium Na Potassium K Calcium Ca Magnesium Mg Iron Fe Oxygen O Nitrogen N Sulphur S Copper Cu Zinc Zn Aluminium Al Gold Au Mercury Hg Fluorine F Chlorine Cl Hydrogen H Helium He
  8. 8. Reactions of metals with oxygen When a metal reacts with oxygen it will form a METAL OXIDE. This is what happens when a metal rusts. We can make this reaction happen quicker by burning the metal. METAL + OXYGEN METAL OXIDE <ul><li>Copy and complete the following reactions: </li></ul><ul><li>Magnesium + oxygen </li></ul><ul><li>Copper + oxygen </li></ul><ul><li>Calcium + oxygen </li></ul><ul><li>Iron + oxygen </li></ul>
  9. 9. Reactions of metals with water When a metal reacts with water hydrogen is always given off. The other product will be either a metal hydroxide or a metal oxide. <ul><li>Copy and complete the following reactions: </li></ul><ul><li>Sodium + water </li></ul><ul><li>Potassium + water </li></ul><ul><li>Calcium + water </li></ul><ul><li>Iron + steam </li></ul>METAL + WATER METAL OXIDE + HYDROGEN METAL + WATER METAL HYDROXIDE + HYDROGEN
  10. 10. Reactions of metals with acids When a metal reacts with an acid it gives off hydrogen (which can be “popped” using a lit splint). The other product is a salt. <ul><li>Copy and complete the following reactions: </li></ul><ul><li>Calcium + hydrochloric acid </li></ul><ul><li>Zinc + hydrochloric acid </li></ul><ul><li>Iron + hydrochloric acid </li></ul><ul><li>Lithium + sulphuric acid </li></ul>METAL + ACID SALT + HYDROGEN e.g. magnesium + hydrochloric acid magnesium chloride + hydrogen
  11. 11. Complete the following reactions: <ul><li>Lithium + water </li></ul><ul><li>Lithium + hydrochloric acid </li></ul><ul><li>Silver + oxygen </li></ul><ul><li>Magnesium + sulphuric acid </li></ul><ul><li>Potassium + oxygen </li></ul><ul><li>Aluminium + oxygen </li></ul><ul><li>Manganese + water </li></ul><ul><li>Sodium + sulphuric acid </li></ul><ul><li>Lithium + oxygen </li></ul><ul><li>Nickel + hydrochloric acid </li></ul>Lithium hydroxide + hydrogen Lithium chloride + hydrogen Silver oxide Magnesium sulphate + hydrogen Potassium oxide Aluminium oxide Manganese oxide + hydrogen Sodium sulphate + hydrogen Lithium oxide Nickel chloride + hydrogen
  12. 12. An example question on reactivity Reacts slowly Reacts with steam only Reasonable reaction E Burns brightly Slow reaction Violent reaction D No reaction No reaction No reaction C Reacts slowly No reaction No reaction B Burns brightly Slow reaction Some reaction A Reaction with oxygen Reaction with water Reaction with dilute acid Metal
  13. 13. The Reactivity Series The Reactivity Series lists metals in order of reactivity: Potassium Sodium Calcium Magnesium Aluminium Carbon Zinc Iron Lead Copper Silver Gold Increasing reactivity
  14. 14. Displacement reactions A displacement reaction is one where a MORE REACTIVE metal will DISPLACE a LESS REACTIVE metal from a compound. Mg Magnesium SO 4 Cu Copper sulphate The magnesium DISPLACES the copper from copper sulphate SO 4 Mg Magnesium sulphate Cu Copper
  15. 15. Displacement reactions A displacement reaction is one where a MORE REACTIVE metal will DISPLACE a LESS REACTIVE metal from a compound. For example, if you drop some magnesium into copper sulphate a reaction will happen because magnesium is more reactive than copper, so the reaction is: Magnesium + copper sulphate copper + magnesium sulphate However, if you drop some copper into magnesium sulphate NOTHING will happen.
  16. 16. Some example reactions… Extension work – write down the equations for these reactions Copper + silver nitrate Copper + lead nitrate Zinc + lead nitrate Zinc + copper sulphate Observations Prediction Reaction
  17. 17. Some example reactions… Extension work – write down the equations for these reactions Reaction DID happen Copper + silver nitrate Reaction DID NOT happen Copper + lead nitrate Reaction DID happen Zinc + lead nitrate Reaction DID happen Zinc + copper sulphate Observations Prediction Reaction
  18. 18. Quiz on acids and alkalis <ul><li>This a pH of less than 7 </li></ul><ul><li>This could kill cells </li></ul><ul><li>A metal hydroxide (e.g. sodium hydroxide) would be an _____ </li></ul><ul><li>When this reacts with a metal hydrogen is released </li></ul><ul><li>A metal carbonate (e.g. calcium carbonate) would be an _____ </li></ul><ul><li>This would feel soapy on your skin </li></ul><ul><li>This could be a corrosive </li></ul><ul><li>This will turn universal indicator purple </li></ul><ul><li>This would taste sour </li></ul><ul><li>This means “a base that can be dissolved” </li></ul>Acid, alkali or both???
  19. 19. Neutralisation reactions When acids and alkalis react together they will NEUTRALISE each other. Neutralisation is an example of a displacement reaction: OH Na Sodium hydroxide Cl H Hydrochloric acid The sodium DISPLACES the hydrogen from HCl Cl Na Sodium chloride H 2 O Water
  20. 20. Neutralisation experiment <ul><li>In this experiment we mixed sodium hydroxide (an _____) and hydrochloric acid together and they ________ each other. The equation for this reaction is… </li></ul><ul><li>Sodium hydroxide + hydrochloric acid sodium chloride + water </li></ul><ul><li>A ____ was formed during the reaction, and we could have separated this by __________ the solution. The salt that we formed depended on the acid: </li></ul><ul><ul><li>Hydrochloric acid will make a CHLORIDE </li></ul></ul><ul><ul><li>Nitric acid will make a _________ </li></ul></ul><ul><ul><li>Sulphuric acid will make a _________ </li></ul></ul>Words to use – nitrate, neutralised, alkali, sulphate, salt, evaporating
  21. 21. Making salts Whenever an acid and alkali neutralise each other we are left with a salt, like a chloride or a sulphate. Complete the following table: Calcium nitrate + water Calcium hydroxide Potassium sulphate + water Potassium hydroxide Sodium chloride + water Sodium hydroxide Nitric acid Sulphuric acid Hydrochloric acid
  22. 22. Salts of transition metals These are the TRANSITION METALS – if we make a salt using a base made from one of these metals the procedure is different… 1) Drop the base into the acid… 2) Filter it to remove any leftover base 3) Evaporate it to get the salt
  23. 23. Extracting Metals Some definitions: A METAL ORE is a mineral or mixture of minerals from which it is “economically viable” to extract some metal. Most ores contain METAL OXIDES (e.g. rust = iron oxide). To “extract” a metal from a metal oxide we need to REDUCE the oxygen. This is called a REDUCTION reaction.
  24. 24. How do we do it? Potassium Sodium Calcium Magnesium Aluminium Carbon Zinc Iron Tin Lead Copper Silver Gold Platinum Increasing reactivity Metals ABOVE CARBON, because of their high reactivity, are extracted by ELECTROLYSIS Metals BELOW CARBON are extracted by heating them with carbon in a BLAST FURNACE These LOW REACTIVITY metals blatantly won’t need to be extracted because they are SO unreactive you’ll find them on their own, not in a metal oxide
  25. 25. Extracting metals <ul><li>What is an ore? </li></ul><ul><li>In what form are metals usually found in the Earth? </li></ul><ul><li>How do you get a metal out of a metal oxide? </li></ul><ul><li>What is this type of reaction called? </li></ul>Low reactivity Middle reactivity (i.e. anything below carbon) High reactivity (i.e anything above carbon) Examples Extraction process Type of metal
  26. 26. The Blast Furnace 1) HAEMATITE (iron ore), limestone and coke (carbon) are fed in here 2) Hot air is blasted in here 3) The carbon reacts with oxygen from the air to form carbon dioxide. 4) The carbon dioxide reacts with more carbon to form carbon monoxide 6) Molten slag (waste) is tapped off here 5) Carbon monoxide reduces iron oxide to iron. The molten iron is tapped off here Iron oxide + carbon monoxide iron + carbon dioxide
  27. 27. Electrolysis Molecule of solid copper chloride Molecule of solid copper chloride after being dissolved Chloride ion Copper ion
  28. 28. Electrolysis Electrolysis is used to extract a HIGHLY REACTIVE metal. When we electrolysed copper chloride the negative chloride ions moved to the positive electrode and the positive copper ions moved to the negative electrode – OPPOSITES ATTRACT!!! = chloride ion = copper ion
  29. 29. Redox reactions These happen during electrolysis: These two processes are called REDOX REACTIONS OILRIG – O xidation I s L oss of electrons R eduction I s G ain of electrons At the positive electrode the negative ions LOSE electrons to become neutral – this is OXIDATION At the negative electrode the positive ions GAIN electrons to become neutral – this is REDUCTION
  30. 30. Purifying Aluminium Aluminium has to be extracted from its ore (called ________) by electrolysis. This is because aluminium is very ___________. The ore is mixed with cryolite to lower its ________ ________. The ore is then melted so that the ions can ______. The positively charged aluminium ions gather at the ___________ electrode. Oxygen forms at the positive electrode and causes it to wear away, which means that they have to be __________ frequently. Words – melting point, replaced, negative, bauxite, reactive, move
  31. 31. Rusting Experiment RUST NO RUST – no water NO RUST – no oxygen
  32. 32. Rusting <ul><li>Rust is formed when iron reacts with water AND oxygen. It’s an example of an oxidation reaction which can be sped up using salt. There are several ways of dealing with rust: </li></ul><ul><li>Regular painting or oiling </li></ul><ul><li>Galvanising – this is when iron objects are coated with zinc </li></ul><ul><li>Making objects out of a non-rusting metal, such as stainless steel </li></ul><ul><li>Attaching zinc bars to ships – the water will react with the zinc before it reacts with the iron, because zinc is more reactive </li></ul>

×