Explain how the Haber process for producing ammonia is a good example of Le Châtelier's principle.

The Le Chatelier principle says that when an external disturbance is imposed on a chemical system in equilibrium, this equilibrium is displaced in order to minimize such perturbation.

the increase in temperature displaces the equilibrium towards the endothermic reaction, and the reduction of the temperature shifts the equilibrium towards the exothermic reaction.

N2 (g) + 3 H2 (g) ↔ 2 NH3 (g) ∆H = - 22 kcal

The value of ΔH (enthalpy change) is negative, which means that the direct reaction is exothermic, with release of heat. And the reverse reaction is endothermic, with absorption of heat.

Therefore, if we increase the temperature of this reaction, there would be a shift towards the endothermic reaction, which is the inverse, in the left (←) direction. With this, the heat will be absorbed to reduce the disturbance caused in the system. A consequence of this temperature increase is that the equilibrium constant (Kc) will increase. If we do the opposite, lowering the system temperature, the direct reaction, the ammonia production, will be favored. This is because it is exothermic and will release heat to the system that is at the lowest temperature.