Question

(a) Name the substance used for drying ammonia.
(b) Write an equation to illustrate the reducing nature of ammonia.
(c) With reference to Haber's process for the preparation of ammonia, write the equation and the conditions required.

Answer 1

1. The substance used for drying ammonia is quick lime.
2. The equation that illustrates the reducing nature of ammonia is: $8{\mathrm{NH}}_3+3{\mathrm{Cl}}_2\to {\mathrm{N}}_2+6{\mathrm{NH}}_4\mathrm{Cl}$
3. The equation for Haber's process is: ${\mathrm{N}}_2+3{\mathrm{H}}_2$⇌ $2{\mathrm{NH}}_3+\mathrm{Heat}$

Required conditions for the formation of ammonia under Haber's process:

• The reaction is favoured by low temperature. To achieve an optimal balance between reaction yield and kinetics, a temperature of about 450^oC–500^oC is maintained.
• The reaction is accompanied by the reduction in the volume of ammonia. So, a high pressure of 200–900 atmospheres is used.
• Finely divided iron is used as a catalyst and molybdenum is used as a promoter.