reactions of metals and the reactivity series

90 elements that occur naturally
1. 70 of these are metals
  1. only a few are in common use
Making salts- acid plus base
1. a base is any compound that can neutralise an acid
  1. Examples: metal oxide - copper oxide metal hydroxide - sodium hydroxide metal carbonates - magnesium carbonate metal hydrogen - calcium hydrogen ammonia
2. Acid + base -------- salt + water
  1. sulphuric acid + copper oxide -------- copper sulphate + water
    1. warm the acid + base then when it is cool, filter the mixture. boil the filtrate and leave the remaining solution in a petri dish the water will evaporate and leave salt crystals behind
Making salts - acid plus carbonate
1. acid + carbonate -------- salt + carbon dioxide + water
  1. nitric acid + magnesium carbonate -------- magnesium nitrate + carbon dioxide + water
    1. keep adding the magnesium carbonate until no more fizzing occurs. filter out the remaining powder that has not reacted, pour it into a petri dish and leave it to evaporate. long thin salt crystals of will form and be left in the petri dish.
Action of Acid on metals
1. to test the effect of hydrochloric acid and sulphuric acid on 4 different metals
  1. Iron Copper Zinc Magnesium
  2. Sulphuric acid
    1. created more hydrogen than the hydrochloric acid.
    2. produced heat with magnesium
  3. Hydrochloric acid
    1. produced heat with magnesium
  4. the most reactive metals produce hydrogen
  5. with this information we can make a reactive series
    1. magnesium (Mg) - produced hydrogen with acid
    2. Zinc (Zn) - slow fizzing reaction with acid
    3. Iron (Fe) - very slow fizzing reaction with acid
    4. Copper (Cu) - no reaction with acid
Making Salts - acid plus metals
1. acid + metal -------- salt + hydrogen
  1. hydrochloric acid + zinc -------- zinc chloride + hydrogen
    1. leave the metal in a test tube full of the acid until a further reaction has finished. when it is heated gently (bunsen flame) salt crystals will form and give off the gas hydrogen
all acids react in the same way when they are tested in these ways
1. action with magnesium: fizzing, turning milky
2. action with copper oxide: strong fizzing, turned blue
3. action with magnesium carbonate: fizzing, turning milky
4. pH: red (1)
Rusting of Iron
1. rusting is the oxidation of iron to form iron oxide
  1. this reaction occurs slowly in damp air
    1. iron + oxygen + water vapour -------- iron oxide (rust)
      1. when water and oxygen are present rusting occurs
      2. when oxygen and/or water is removed, the rusting is reduced
Extraction of Copper
1. all of the copper on the earths crust is found as copper compounds or ores.
  1. one of the copper ores is malachite. there are three stages in extracting the copper from malachite.
    1. STAGE 1
      1. turn the malachite into copper oxide
        THERMAL DECOMPOSITION
        copper carbonate --heat-- copper oxide + carbon dioxide
        when it is heated, carbon dioxide will be let out - keep reacting until no more carbon dioxide is produced
        black copper oxide and carbon dioxide gas were formed.
    2. STAGE 2
      1. change the copper oxide into copper sulphate
        copper oxide is a base. it dissolves in an acid to make a neutral solution that contains a salt.
        acid + base -------- salt + water
        sulphuric acid + copper oxide -------- copper sulphate + water
        heat the mixture of copper oxide and sulphuric acid until it reaches 70 oC and then filter off the unreacted copper oxide and keep the copper sulphate solution to use in stage 3.
        heating the copper oxide withe the sulphuric acid formed the blue copper sulphate solution. the excess copper oxide was removed by filtration
    3. STAGE 3
      1. remove the copper from the copper sulphate
        compounds can be broken down using electricity (electrolysis)
        when copper sulphate is electrolysed, it breaks down to form copper metal, sulphuric acid and oxygen
        copper sulphate + water --electrolysis-- copper + sulphuric acid + oxygen
        when an electric current is passed through the solution for about 5 minutes the compound decomposes
        therefore electrolysis can be used to extract metals from their ores.
Reactivity of metals
1. Some metals are more reactive than others.
  1. The alkali metals (group 1) are highly reactive.
    1. when reacted with water, they produce hydrogen gas.
      1. metal + water -------- alkali + hydrogen
        more reactive metals displace less reactive metals from their compounds.
        for example, iron is more reactive than copper.
        Iron + copper sulphate -------- iron sulphate + copper
        THIS IS CALLED A DISPLACEMENT REACTION
2. potassium sodium lithium calcium magnesium aluminium carbon (C) zinc (Zn) iron (Fe) copper silver(Ag) gold
  1. This is a Reactive Series
  2. the elements below carbon can be isolated by heating their ore with carbon. The carbon displaces the metal from its ore.

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reactions of metals and the reactivity series

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	Criado por spencerwinn quase 11 anos atrás