Haber's process is used for the synthesis of ammonia. The optimum temperature for the Haber process is:

Explanation

Option C is correct. The optimum temperature for the Haber process is 400-450°C. This temperature range strikes a balance between reaction rate and yield. While lower temperatures favor the formation of ammonia, they slow the reaction significantly, making production inefficient. Conversely, higher temperatures increase the reaction rate but diminish the yield due to the equilibrium of the reaction shifting away from ammonia production. At 400-450°C, the reaction is fast enough to be practical, and the yield is high enough to ensure that the process remains economically viable. The Haber process is typically conducted at high pressures (200-400 atm) with an iron catalyst to further enhance ammonia production.