Le Chatelier's Principle and Industrial Processes

Once a system reaches equilibrium, it will stay there unless something disturbs it. Le Chatelier's principle predicts the direction in which a system responds to such disturbances. It states that if a change is imposed on a system at equilibrium, the position of equilibrium shifts in the direction that tends to counteract, or partially oppose, that change. This principle lets us predict qualitatively how concentration, pressure, and temperature changes affect a reaction, and it underpins the design of major industrial processes.

Consider first a change in concentration. Take the equilibrium $Fe^{3+}(aq) + SCN^-(aq) \rightleftharpoons FeSCN^{2+}(aq)$, where the product is deep red. If we add more $SCN^-$, the system opposes the increase by consuming some of it, shifting to the right and dee