Le-Chatlier’s principle is a fundamental concept in chemical equilibrium. It states that if a stress is applied to a system at equilibrium, the position of the equilibrium will shift in a way that tends to counteract the applied stress and re-establish equilibrium. This principle allows us to predict how a chemical equilibrium will respond to changes in various factors:
- Pressure: If pressure is increased, the equilibrium will shift towards the side with fewer gas molecules to reduce the overall pressure. Conversely, decreasing pressure will favor the side with more gas molecules.
- Temperature: The effect of temperature depends on whether the reaction is exothermic (releases heat) or endothermic (absorbs heat). Increasing temperature favors the endothermic reaction (to consume the added heat), while decreasing temperature favors the exothermic reaction (to release heat).
- Concentration: If the concentration of a reactant is increased, the equilibrium will shift to consume the added reactant, favoring the product side. Conversely, decreasing the concentration of a reactant will favor the reactant side. Similarly, changes in product concentration will also affect the equilibrium position in the opposite direction.
Therefore, Le-Chatlier’s principle helps us predict the effect of changes in pressure, temperature, and concentration on a chemical equilibrium.
