The Haber Process :: essays research papers

1. The Haber transitionDuring the first decade of the twentieth century the world-wide demand for ammonia for call in fertilisers (in the form of nit ordinates) and in the production of explosives for use in archeological site and warfare could only be satisfied on a too large scale from deposits of guano in Chile (2). Though this deposit was of huge coat (approximately five feet thick and 385 kilometres long) it represented a rapidly depleting resource when compared to world-wide demand. As a result of this there was much research into how ammonia could be produced from atmospheric nitrogen. The problem was eventually solved by Fritz Haber (1868 - 1934) in a process which came to be known as the "Haber surgery" or the "Haber - Bosch Process".Haber developed a method for synthesising ammonia utilising atmospheric nitrogen and had accomplished the conditions for large scale synthesis of ammonia by 1909 and the process was pass over to Carl Bosch for industrial development (1). the reception is a simple balance response which occurs in gaseous state as followsN2 (g) + 3H2 (g) = 2NH3 (g) heat of henry = -92.6 kJ/molIn predicting how to obtain the highest yield from this reaction we must denote to Le Chatliers Principle. This states that for an equilibrium reaction the equilibrium will work in the opposite direction to the conditions forced upon it. The conditions most pertinent to the in a higher place reaction are temperature and pressing.The pressure exerted by any gas or mixing of gasses in an enclosed space is directly proportional to the number of atoms or molecules of gas regardless of their size or molecular mass. Reference to the above reaction shows that, as the reaction moves to the right the number of molecules and hence the pressure decreases. Therefore the reaction moving to the right (i.e. towards the product required) is favoured by an increase in pressure.With regard to temperature, the reaction moving to the right i s exothermic i.e. it gives eat up naught (in the form of heat). Therefore reference to Le Chatliers Principle shows that the reaction to the right is favoured by low temperatures.However, when Haber placed the reactants together under these conditions it was shown that the rate of reaction was so slow as to render the process unworkable as an industrial process. This is because of an unusually high activation energy.The activation energy of a reaction is the energy required by the reactants to achieve an mediate state required before they form the products.