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Thursday, 11 July 2013

The reaction between acids and metals
when metals reacts with an acid they produce hydrogen and a salt e.g. sulfate, nitrate, chloride and ethanoate. in our experiments we used the same metal (magnesium) and reacted it with four different acids.
  • ·        Metal + acid = salt + hydrogen
  • ·        Metals like copper and salt do not react with dilute acids
  • ·        Reactive metals like lithium, sodium, potassium and calcium react violently with dilute acids
  • ·        (H2) hydrogen is colourless and odourless. You may be able to hear a squeaky pop sound when a burning splint is held over a test tube which has hydrogen gas present.
  • ·        Nitrate, chloride, ethanoate and sulfate are all types of salts

  • ·        Ethanoic acid + magnesium strip = magnesium ethanoate + hydrogen

You know that a reaction has occurred due to violent fizzing, a release of heat, the substance becomes cloudy, the magnesium strip begins to corrode before disappearing, changes to an orange colour.
  • ·        Sulphuric acid + magnesium strip = magnesium sulphate + hydrogen  

Reaction has occurred when magnesium is floating at the top of the substance, it begins to bubble and become cloudy, changes colour to a pink rather than red, magnesium strip may disappear
  • ·        Hydrochloric acid + magnesium strip = magnesium chloride + hydrogen

Reaction has occurred when the substance begins to bubble and turn cloudy, magnesium floats to the surface before gradually disappearing, less violent than ethanoic reaction, the substance heats up as the hydrogen gas levels increase, changes colour to red
  • ·        Nitric acid + magnesium strip = magnesium nitrate + hydrogen

Reaction has occurred when the substance begins to fizz and bubble, turns a red colour before going yellow, goes cloudy, mixture begins to warm, magnesium sinks to the bottom before disappearing
Mg(s) + 2CH3COOH(aq) --> Mg(CH3COO)2(aq) + H2 (g)
H2SO4 + Mg = MgSO4 + H2
2HCl + Mg = MgCl2 + H2
2HNO3 + Mg = Mg(NO3) + H2

Magnesium fizzing in hydrochloric acid

The final results of the reactions listed above


Acids used in the experiments above

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