The correct answer
is B. Molybdenum (Mo) is a promoter for iron in the Haber process. It increases the activity of the iron catalyst and lowers the temperature required for the reaction to occur.The Haber process is a chemical reaction that is used to produce ammonia from nitrogen and hydrogen. The reaction is exothermic, meaning that it releases heat. The reaction is also reversible, meaning that it can go in both directions. The Haber process is carried out at high temperatures and pressures.
The iron catalyst is used to speed up the reaction. However, the iron catalyst is not very active at high temperatures. Molybdenum is added to the iron catalyst to increase its activity. Molybdenum also helps to prevent the iron catalyst from being poisoned by impurities in the reactants.
The Haber process is an important industrial process. Ammonia is used to produce fertilizers, explosives, and other chemicals. The Haber process is also used to produce nitric acid, which is used to produce explosives, dyes, and other chemicals.