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