1. Nitrogen
    1. fractional distillation of air
    2. uses
      1. inert gas
        1. unreactive
      2. food packaging
        1. protective atmosphere
        2. no oxygen
          1. no oxidation
          2. preserved
    3. diatomic element
  2. aqueous ammonia
    1. ammonia + water ----> ammonium ion + hydroxide ion
    2. NH3 (g) + H2O (l) ---> NH4+ (aq) + OH- (aq)
    3. solution
      1. alkaline
      2. UI paper & red litmus paper
        1. blue
        2. not a test for ammonia!
        3. any alkaline solution
    4. test for ammonium ion
      1. Ammonium ion solution + dilute sodium hydroxide solution
        1. heat
          1. red litmus paper = blue in ammonia gas
  3. Ammonia
    1. fertilisers
    2. Haber Process
      1. industrial manufacture
    3. only common alkaline gas
    4. Lab Preparation
      1. ammonium chloride + calcium hydroxide ---> ammonia + water + calcium chloride
      2. 2NH4Cl + Ca(OH)2 ---> 2NH3 + 2H2O + CaCl2
    5. Properties
      1. colourless gas
      2. less dense than air
        1. lighter
      3. very soluble in water
      4. common alkaline gas
  4. Ammonium Salts
    1. react with acids
      1. salts
        1. react with base
          1. ammonia gas
          2. ammonia chloride + calcium hydroxide ---> ammonia
      2. 2NH3 (aq) + H2SO4 (aq) ---> (NH4)2SO4 (aq)
      3. ammonia solution + dilute sulphuric acid ---> ammonium, sulphate
      4. +nitric acid
        1. =ammonium nitrate