Ammonia

Question 1

Physical properties of NH3

Answer 1

• less dense than air
• non electrical conductor as air
• highly soluble in water
• once dissovled in water, becomes an electrical conductor due to the presence of free moving ions.
• low mp/bp, pungent gas at rtp

Question 2

chemical properties of NH3

Answer 2

• dissociates in water to form weak alkali (NH3+H2O–>NH4+OH-)
• precipitate metal hydroxides from their aq. solutions (2NH3+2H2O+ZnSO4–>(NH4)2SO4+Zn(OH)2)
• displaced by strong alkali from its salts (NaOH+NH4CL–>NaCl+H2O+NH3)

Question 3

Raw materials for Haber Process

Answer 3

• Nitrogen from fractional distillation of liquified air
• hydrogen from cracking of crude oil

Question 4

Conditions for Haber’s process

Answer 4

• 200 atm
• 450 degree celsius
• finely divided iron catalyst

Question 5

Description of Haber Process

Answer 5

• mixture of 3 parts hydrogen and 1 part nitrogen is compressed to 200 atm
• mixture is passed into a catalytic chamber containing iron catalyst heated to temperature of around 450 degree celsius
• under high pressure and temp, H2 react with N2 to form NH3 (3H2+N2⇌ 2NH3)
• The ammonia formed is condensed into a liquid and collected
• since the reaction is reversible, the reaction does not go to 100% completion; hence unreacted H2 and N2 gases are pumped back into the reaction chamber to be reused