N2 (g)+3H2 (g) ⇋ 2NH3 (g) ΔH=-92kJmol-1 (this is the equation for the above question)
According to Le Chatelier's principle, the position of equilibrium will shift to minimise the change made to the conditions. In this case, to shift the equilibrium to the right hand side, the optimum conditions would be high pressure and low temperature. High pressure means that, the system will shift to minimise the pressure change, by favouring the side that produces the least amount of moles, which is the right side. Also, because the reaction is exothermic, the decrease in temperature will cause the system to shift to favour the exothermic reaction, which, is also the desired product.
However, these conditions will not be the best to use in industry. Even though high pressure will also increase the rate of reaction, it can be very hazardous and hard to control, and will also require a large amount of energy. With low temperature, the rate of reaction will be lower than at higher temperatures, because less collisions will happen in a given time. Due to these problems, in industry the conditions are more likely to be a higher temperature and a lower pressure than what is optimum for the system.