is obtained from water gas and nitrogen from fractional distillation of liquid air. Properties Ammonia is a pungent smelling gas and is lighter than air. It can be readily liquefied by at about atmospheric pressure. The liquid boils at - .
°C and freezes at - ° C. Liquid ammonia resembles water in its physical properties. i.e. it is highly associated through strong hydrogen bonding.
Ammonia is extremely soluble in water ( Volume in Volume of water) at °C and 760mm pressure. At low temperatures two soluble hydrate NH .H O and 2NH .H O are isolated. In these molecules ammonia and water are linked by hydrogen bonds. In aqueous solutions also ammonia may be hydrated in a similar manner and we call the same as (NH .H O) NH H O NH OH ⇀ ↽ The dielectric constant of ammonia is considerably high to make it a fairly good ionising solvent like water.
⇀ ↽ 2NH NH NH K [NH ][NH C 2H O H O OH K H O OH C ⇀ ↽ ][ Chemical Properties Action of heat: Above °C ammonia decomposes into its elements. The decomposition may be accelerated by metallic catalysts like Nickel, Iron. Almost complete dissociation occurs on continuous sparking. 2NH N 3H > → C Reaction with air/oxygen: Ammonia does not burn in air but burns freely in free oxygen with a yellowish flame to give nitrogen and steam.
4NH 2N 6H O ⇀ ↽ In presence of catalyst like platinum, it burns to produce nitric oxide. This process is used for the manufacture of nitric acid and is known as ostwalds process. 4NH 4NO 6H O ⇀ ↽ Reducing property: Ammonia acts as a reducing agent. It reduces the metal oxides to metal when passed over heated metallic oxide.
XII XII - - - - 3PbO + 2NH 3Pb + N 3H O Reaction with acids: When treated with acids it forms ammonium salts. This reaction shows that the affinity of ammonia for