A chemical engineer for a fertilizer company is determining the most efficient way to produce ammonia. the engineer carries out the haber reaction under four different conditions. according to these data, which procedure gave the greatest percent yield?

Haber's process is used for the industrial production of ammonia. The process conditions at which maximum yield can be obtained, include 15-20mPa pressure, 400-500 degrees Celsius of the temperature, use of methane as a source of hydrogen, use of iron-based catalysts and combined with K2O, CaO, SiO2, and Al2O3. Reuse of unreacted gases can lead to the achievement of 97% yield.