Choosing Reaction Conditions Flashcards
All 4 cards in this deck
What is the trade-off that decides the temperature used in the Haber process?
A lower temperature gives a higher yield of ammonia but a slower rate, so about C is a compromise between yield and rate.
Why is a pressure of about atmospheres used in the Haber process rather than a much higher pressure?
Higher pressure gives a higher yield, but high-pressure equipment and the energy to compress the gases are very expensive (and less safe).
True or false? Using the iron catalyst increases the percentage yield of ammonia.
False. The catalyst speeds up the reaction (equilibrium is reached sooner) but does not change the position of equilibrium or the yield.
On a graph of percentage yield of ammonia against temperature at constant pressure, what does the line do?
The yield falls as the temperature increases.