In the synthesis of ammonia from its constituent elements, what is the coefficient of hydrogen in the stoichiometric equation?
Well, I would write
This is a high pressure process, which could also be represented as,
The reaction is normally carried out at 200 atm and high temperatures, and catalyzed on metal or metal oxide surfaces. It is one of the most important industrial reactions, in that without such a reaction we would not be able to grow nitrogenous fertilizer with which to grow food.
Given the bond energy of the