Le Chatelier’s Principle

• What is Le Chatelier's principle?

  Changing conditions affects equilibrium reactions
• How does a system respond to changes according to Le Chatelier's principle?

  The system will try to counteract the change
• What happens to a reversible reaction at equilibrium when conditions change?

  • The system responds to counteract the change
  • It tries to restore equilibrium
• What does a reversible reaction involve according to Le Chatelier's principle?

  It involves changes in conditions affecting equilibrium
• What can be predicted using Le Chatelier's principle?

  The effect of changes on a reaction system
• How does temperature change affect a reaction at equilibrium?

  1. Increase in temperature shifts equilibrium
  2. Decrease in temperature shifts equilibrium
  3. Direction depends on exothermic or endothermic nature
• What direction do reactions proceed in when temperature is increased?

  Depends on whether the reaction is exothermic
• What happens to products when temperature is decreased in an exothermic reaction?

  More products are formed
• How do reactions behave in terms of direction when pressure is changed?

  Reactions shift towards fewer gas molecules
• What happens when pressure is increased in a gas-phase reaction?

  The equilibrium shifts to reduce pressure
• What is the effect of increasing pressure on a reaction with more moles of gas on one side?

  • Equilibrium shifts towards the side with fewer moles
  • This reduces the total gas volume
• What is the effect of decreasing pressure on a reaction with fewer moles of gas?

  Equilibrium shifts towards more moles of gas
• How does changing concentration affect equilibrium?

  The system shifts to counteract the concentration change
• What happens if the concentration of reactants is increased?

  Equilibrium shifts towards products
• What is the result of decreasing the concentration of products?

  Equilibrium shifts towards products
• What are the effects of changing concentration, pressure, and temperature on equilibrium?

  • Concentration: shifts to counteract change
  • Pressure: shifts towards fewer gas moles
  • Temperature: shifts based on reaction type (exothermic/endothermic)
• What is the balanced equation used for in reactions?

  To determine which side has more gas molecules
• How does changing the concentration of reactants affect equilibrium?

  The system will no longer be at equilibrium
• What happens when the concentration of products is increased?

  The system shifts to restore equilibrium
• What happens if you change the concentration of reactants or products in a system?

  The system will no longer be at equilibrium
• How does the system respond to bring itself back to equilibrium?

  It responds by adjusting concentrations
• What happens if you increase the concentration of reactants?

  The system tries to increase product formation
• What occurs if you decrease the concentration of products?

  The system tries to increase product concentration
• What is an equilibrium in a chemical reaction?

  • A state where reactants and products are in balance
  • The rates of the forward and reverse reactions are equal
  • Concentrations of reactants and products remain constant
• How is an equilibrium similar to a particular type of molecule?

  It is like a particularly stubborn mule
• What does the reaction do when you increase the temperature?

  The equilibrium shifts towards the endothermic reaction
• What is the effect of increasing pressure on a reaction with more gas molecules on one side?

  The equilibrium shifts towards the side with fewer gas molecules
• How many molecules of gas are on the left side of the reaction CO(g) + H₂O(g) ⇌ H₂(g) + CO₂(g)?

  2 molecules
• How many molecules of gas are on the right side of the reaction 2CO(g) + O₂(g) ⇌ 2CO₂(g)?

  2 molecules
• What happens to the equilibrium if you increase the pressure in the reaction N₂ + 3H₂ ⇌ 2NH₃?

  The equilibrium shifts towards the right side
• What is the effect of increasing the concentration of NH₃ on the equilibrium?

  The equilibrium shifts towards the left side
• What is the effect of increasing the concentration of N₂ on the equilibrium?

  The equilibrium shifts towards the right side
• What are the factors affecting chemical equilibrium?

  • Concentration changes of reactants or products
  • Temperature changes
  • Pressure changes (for gaseous reactions)
• What is the equilibrium constant expression for the reaction aA + bB ⇌ cC + dD?

  K = [C]^c [D]^d / [A]^a [B]^b
• What does a large equilibrium constant indicate?

  Products are favored at equilibrium
• What does a small equilibrium constant indicate?

  Reactants are favored at equilibrium
• What is the relationship between temperature and equilibrium constant?

  • The equilibrium constant changes with temperature
  • For exothermic reactions, K decreases with increasing temperature
  • For endothermic reactions, K increases with increasing temperature
• What is the effect of a catalyst on equilibrium?

  A catalyst speeds up the attainment of equilibrium
• What is the significance of Le Chatelier's principle?

  It predicts how a system at equilibrium responds to changes
• What are the applications of chemical equilibrium in industry?

  • Optimization of product yields
  • Control of reaction conditions
  • Design of chemical processes