Ammonia synthesis free energy change

The production of ammonia is of historical interest because it represents the first important application of thermodynamics to an industrial process. Considering the synthesis reaction of ammonia from its elements, the calculated reaction heat (AH) and free energy change (AG) at room temperature are approximately -46 and -16.5 KJ/mol, respectively. Although the calculated equilibrium constant = 3.6 X 108 at room temperature is substantially high, no reaction occurs under these conditions, and the rate is practically zero. The ammonia synthesis reaction could be represented as follows ... 

Because the free-energy change for any process at constant temperature and pressure is AG = AH — TAS, we can calculate the standard free-energy change AG° for a reaction from the standard enthalpy change AH0 and the standard entropy change AS°. Consider again the Haber synthesis of ammonia ... 

Calculate the free-energy change for ammonia synthesis at 25°C (298 K) given the following sets of partial pressures ... 

For chemical reactions we are often interested in the standard free energy change (AG°), the change in free energy that occurs if the reactants in their standard states are converted to the products in their standard states, For example, for the ammonia synthesis reaction at 25°C,... 

To see how the change in free energy for a reaction depends on pressure, we will consider the ammonia synthesis reaction... 

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