Reverse Haber process

An example of a zero-order reaction is the reverse Haber process ... 

Although the atmosphere is 78% nitrogen gas (N2), it is not available (i.e., able to be used) to plants or animals except after it has been fixed. Thus, the development of the process for making ammonia from hydrogen and atmospheric nitrogen by Haber was extremely important. The first reaction (1) in Figure 1.4 shows the reaction carried out in the Haber process. This reaction is reversible so ammonia is compressed and cooled, and liquid ammonia is removed from the reaction mixture to drive the reaction to the right. 

The Haber Process Ammonia (NH3) is used in the production of fertilizer, refrigerants, dyes, and plastics. The Haber process is a method of producing ammonia through a reaction of molecular nitrogen and hydrogen. The equation for the reversible reaction is ... 

Let us look again at the Haber process. The reverse reaction of the Haber process is favored by adding heat. Thus we place the word Heat on the right side of Equation 11.22. 

The production by this method was developed originally by Haber after whom the process is now named. Since the reaction is reversible... 

Nj -h SHj = = > 2NH3 The process is reversible and exothermic. The process operates at high temperatures because at low temperature the rate of reaction would be too slow for equilibrium to be reached in a reasonable time. Thus, high temperature, 450 degC, and high pressure, 250 atmospheres, is used to increase the yield. An iron catalyst is used. The process was invented by the German chemist, Fritz Haber in I909AD. 

Briefly, the Haber-Bosch process is a reaction that is reversible and exothermic ... 

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