In the Ostwald process, ammonia is converted to nitric acid when ammonia is burn
ID: 966386 • Letter: I
Question
In the Ostwald process, ammonia is converted to nitric acid when ammonia is burned in air at 900 degrees C in the presence of a platinum-rhodium catalyst.
In the Ostwald process, ammonia is converted to nitric acid when ammonia is burned in air at 900degree C in the presence of a platinum-rhodium catalyst. 4NH_3(g) + 5O_2(g) 4NO(g) + 6H_2O(g) Assuming that the reaction is at equilibrium, what will happen if more nitrogen monoxide is added to the reaction vessel? Fill in the blanks to complete the sentence below. The equilibrium will shift to the because the of a productExplanation / Answer
We write down the equilibrium constant KC for the reaction
4 NH3 (g) +5O2 (g) <======> 4 NO (g) + 6H2O (g)
as KC = [NO]4[H2O]6/[NH3]4[O2]5 where the terms within square braces indicate molar concentrations at equilibrium.
Now, when more nitrogen monoxide, NO is added to the vessel at equilibrium, the numerator of the KC expression increases. Kc is the equilibrium constant and is only dependent on the temperature. This means that at a constant temperature, the value of Kc will remain constant. Hence, when the numerator of the expression increases, to keep KC constant, the denominator must also increase. This is possible only when the molar concentrations of the reactant NH3 and O2 increase, i.e, there will be more formation of reactants. In other words, the reaction will shift to the left hand side (backward reaction favoured).
Ans: The equilibrium will shift to the left/backward direction because the concentration/amount of a product increases.