Friday, October 14, 2011

Chemistry Form 4: Chapter 9 - Haber Process

  1. The physical properties of ammonia are:
    • Colourless and alkaline gas
    • Strong pungent smell
    • Highly soluble in water
  1. Ammonia usually produces white fumes of ammonium chloride when reacted with hydrogen chloride.
  1. The main uses of ammonia are:
    • Manufacturing nitrogen fertilizers
    • Manufacturing nitric acid through Ostwald process.
    • To make explosives, dyes, household cleaners and nylon
    • As a cooling agent.
Making of Ammonia
Ammonia is manufactured by combining nitrogen and hydrogen in an important industrial process called the Haber process. The reaction is reversible and the production of ammonia is exothermic.

  • Nitrogen gas is obtained from the fractional distillation of liquid air.
  • Hydrogen gas is obtained through the reaction between natural gas and steam.
  • Nitrogen and hydrogen are mixed in the ratio of 1 : 3

Click on the diagram below to play!

How to separate ammonia
When the gases leave the reactor they are hot and at a very high pressure. Ammonia is easily liquefied under pressure as long as it isn't too hot, and so the temperature of the mixture is lowered enough for the ammonia to turn to a liquid. The nitrogen and hydrogen remain as gases even under these high pressures, and can be recycled.

 An ammonia production plant. Photo courtesy of WMC Resources Ltd

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