Final answer:
Le Chatelier's principle predicts that a system at equilibrium will react to changes in pressure, temperature, and concentration by shifting to minimize those changes, although adding a catalyst does not shift the equilibrium.
Step-by-step explanation:
Le Chatelier's principle can be used to predict how a chemical system at equilibrium will respond to changes in pressure, temperature, and concentration. This principle states that if a stress is applied to a system at equilibrium, the system will adjust in such a way to minimize the stress. This could involve a shift in the direction of the forward or reverse reaction. Changes in pressure and volume will affect the system if there is a different number of moles of gases on the reactant and product sides. However, the addition of a catalyst does not change the equilibrium but helps the reaction reach equilibrium more quickly.