Which graph shows how pressure and temperature affect the yield of ammonia produced by the Haber process? (A) - HSC - SSCE Chemistry - Question 12 - 2006 - Paper 1

In the Haber process for the synthesis of ammonia, the yield is influenced by both temperature and pressure. Generally, increasing the pressure favors the formation of ammonia since there are fewer moles of gas on the product side. Meanwhile, lower temperatures typically increase the yield due to the exothermic nature of the reaction, but they also slow down the reaction rate. Therefore, you'll often find that graphs representing this relationship will show curves denoting higher yields at certain combinations of pressure and temperature.

Given these considerations, the graph that clearly illustrates how the yield increases with pressure and shows different yield levels at various temperatures is the correct one.

From the options provided in the question, option (A) represents this relationship accurately.