Ammonia is produced by the Haber process, in which nitrogen and hydrogen are reacted directly using an iron mesh impregnated with oxides as a catalyst. For the reaction
N2(g) + 3H2(g) <=> 2NH3(g)
equilibrium constants (Kp values) as a function of temperature are
300 degrees C, 4.34x10^-3
500 degrees C, 1.45x10^-5
600 degrees C, 2.25x10^-6
Is the reaction exothermic or endothermic?