Question

1. Name the process used to manufacture ammonia from its elements.
2. Under what conditions do the reactants combine to form ammonia? Give a balanced equation for the reaction.
3. In what ratio by volume, are the above reactants used.
4. State one possible source of each reactant used in the process.
5. What is the function of:
   1. finely divided iron,
   2. molybdenum in the above process.
6. Mention two possible ways by which ammonia produced is removed from unchanged gases.

Answer 1

1. Haber’s process
2. Nitrogen reacts with hydrogen under specific conditions, liberating ammonia.
   \[\ce{N2 + 3H2 <=> 2NH3 + \Delta}\]
   The required conditions are temperature, pressure, a catalyst, and a promoter.
3. According to the above equation, nitrogen and hydrogen combines in 1 : 3 ratio by volume.
4. Nitrogen is obtained by fractional distillation of liquid air. Hydrogen is obtained from the water gas (Bosch process) or from natural gas.
5. 1. Finely divided iron increases the reaction rate.
   2. Molybdenum acts as a promoter, increasing the catalyst’s efficiency.
6. 1. By liquefaction: Ammonia liquefies more easily than nitrogen and hydrogen.
   2. By absorbing in water: Because ammonia is highly soluble in water, whereas hydrogen and nitrogen are very slightly soluble.