DESCRIBE THE FAVOURABLE CONDITIONS FOR THE MANUFRACTURE OF :
1. NH3 BY HABER PROCESS.
2. H2SO4 BY CONTACT PROCESS.
According to Le Chateliar's principle the low temperature and high pressure is favourable. Increasing the pressure will shift the equilibrium in right as number of moles of reactant is more than product.Since the reaction is exothermic lowering of temperature is favourable.
The pressure and temperature use in manufacure of NH3 in haber process is shown in orange box in diagram above.
Synthesis of H2SO4 in contact process involves 2 steps.
1)synthesis of SO3
2)Reaction of SO3 with H2SO4 followed by reaction of product with water:
Since only first step involves equilibrium we will discuss the condition according to it.
According to Le Chateliar's principle the low temperature and high pressure is favourable. Increasing the pressure will shift the equilibrium in right as the number of moles of reactant is more than product.Since the reaction is exothermic lowering of temperature is favourable. But the condition used in industries are shown below:
According to the Le Chateliar's principle high pressure is favourable for the formation of ammonia.The optimum conditions for the production of ammonia through Haber's process are a pressure of 200 atm, a temperature approximately of about 700 K and use of catalyst such as iron oxide with small amounts of K2O and Al2O3 toincrease the rate of attainment of equilibrium.
low temperature and high pressure are favourable conditions for maximum yield of sulphuric acid. because the reaction is exothermic, reversible, and the forward reaction leads to decrease in volume for the below reaction
2SO2 +O2 in presence of V2O5 catalyst gives 2SO3
but very low temperature slows downn the rate of the reaction.
In the contact process the plant is operated at a pressure of 2 bar and a temperature of 720 K.