le chataliers principle

• Dynamic equilibrium


  Equilibrium in terms of concentrations and rate
• Equilibrium Constant


  1. Write

  2. Calculate

  3. Manipulate
• Le Chatelier's Principle


  • Changes in concentration, pressure, or temperature can disturb the equilibrium and lead to a shift in the equilibrium position
• Position of equilibrium


  Relative amounts of reactants and products present at equilibrium
• Equilibrium doesn't mean that there are 50% reactants and 50% products
• Equilibrium shift to the right


  Favors the forward reaction, more products are made
• Equilibrium shift to the left


  Favors the backward reaction, more reactants are made
• Changes made to a reaction at equilibrium

  1. Changes to the concentrations of reactants and products

  2. Changes to the pressure of a system involving gaseous reactants and products

  3. Changes to the temperature
• If more of a reactant is added to an equilibrium mixture


  The system will respond to use up the added reactant
• If a product is removed from an equilibrium mixture


  The system will respond to replace it
• Endothermic reaction


  Reaction that absorbs heat
• Exothermic reaction


  Reaction that releases heat
• If temperature is increased


  Equilibrium position will shift in the endothermic direction
• If temperature is decreased


  Equilibrium position will shift in the exothermic direction
• A catalyst increases the rate of a chemical reaction by providing an alternative reaction pathway with a lower activation energy
• The presence of a catalyst has no effect on the equilibrium position because a catalyst increases the rate of both the forward and reverse reactions by the same amount
• The advantage of using a catalyst is that the equilibrium is established more quickly, which is an economic benefit
• Changes and their effects on equilibrium

  • Concentration of SO2 increased
  • Concentration of O2 decreased
  • Concentration of SO3 decreased
  • Pressure increased
  • Temperature increased