Final answer:
In the commercial production of ammonia, conditions of high temperature, high pressure, and the presence of a catalyst are used to optimize the rate, yield, and cost effectiveness of the process.
Step-by-step explanation:
In the commercial production of ammonia, conditions of about 500 °C, 150-900 atm, and the presence of a catalyst are used to give the best compromise among rate, yield, and the cost of the equipment necessary to produce and contain high-pressure gases at high temperatures (Figure 17.20).
High pressures of reactants (~150-250 atm) are used to shift the equilibrium right, favoring product formation. Ammonia is continually removed from the equilibrium mixture during the process, lowering its concentration and also shifting the equilibrium right.
Although low temperatures favor product formation, a catalyst is used to accelerate the reaction to reasonable rates at relatively moderate temperatures (400-500 °C). One way to increase the yield of ammonia is to increase the pressure on the system in which N2, H2, and NH3 are at equilibrium or are coming to equilibrium.