Introduction to Le Chatelier's Principle

• Definition: Le Chatelier's Principle states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium moves to counteract the change.

• Purpose: This principle helps predict how a change in conditions (concentration, temperature, pressure) will affect the position of an equilibrium in a chemical reaction.

Key Concepts of Le Chatelier's Principle

• Change in Concentration:

  • Adding more reactant or removing product shifts the equilibrium to the right (towards products).

  • Adding more product or removing reactant shifts the equilibrium to the left (towards reactants).

• Change in Temperature:

  • For exothermic reactions: Increasing temperature shifts equilibrium to the left; decreasing temperature shifts it to the right.

  • For endothermic reactions: Increasing temperature shifts equilibrium to the right; decreasing temperature shifts it to the left.

• Change in Pressure:

  • Increasing pressure favors the side of the reaction with fewer moles of gas.

  • Decreasing pressure favors the side with more moles of gas.

• Catalysts: Speed up both the forward and reverse reactions equally, thus not affecting the position of equilibrium, but reaching it faster.