CHEMICAL REACTIONS

• metal + water --> metal hydroxide + hydrogen gas
• metal oxide + acid --> salt + water
• acid + metal --> salt + hydrogen gas
• acid + base --> salt + water
• acid + metal carbonate --> salt + water + carbon dioxide
• detecting chemical reactions

  colour change

  a gas is given off

  heat is produced

  change in pH

  precipitate is formed
• reactivity series - most reactive to least reactive -

  K potassium

  Na sodium

  Ca calcium

  Mg magnesium

  Al aluminium

  Zn zinc

  Fe iron

  Pb lead

  Cu copper

  Hg mercury

  Ag silver

  Au gold
• reduction is the removal of oxygen
• oxidation is the addition of oxygen
• a redox reaction is when reduction and oxidation occur simultaneously in a reaction
• combustion is when an element is reacted with oxygen to form an oxide by burning

  eg ; calcium + oxygen --> calcium oxide
• displacement is when a more reactive element displaces a less reactive element from a compound which contains a less reactive element

  eg ; copper oxide / black / + calcium / silver / --> calcium oxide / white / + copper / brown /