In the Haber process for the industrial manufacturing of ammonia involving the reaction, ${\mathrm{N}}_2\left(\mathrm{g}\right)+3\mathrm{H}2\left(\mathrm{g}\right)\rightleftarrows 2{\mathrm{NH}}_3\left(\mathrm{g}\right)$ at 200 atm pressure in the presence of a catalyst, a temperature of about ${500}^o\mathrm{C}$ is used. This is considered as optimum temperature for the process because :

yield is maximum at this temperature

catalyst is active only at this temperature

energy needed for the reaction is easily obtained at this temperature

rate of the catalytic reaction is fast enough while the yield is also appreciable for this exothermic reaction at this temperature