6.2 Reversible reactions and dynamic equilibrium

• What are reversible reactions?


  Reactions where products can form reactants
• How can the direction of a reversible reaction be changed?


  By changing the conditions of the reaction
• What symbol is used to represent a reversible reaction?


  ⇌
• In the Haber Process, what is the reaction represented as?


  Hydrogen + Nitrogen ⇌ Ammonia
• What happens if a reversible reaction is endothermic one way?


  It is exothermic in the opposite direction
• What is transferred in a reversible reaction?


  The same amount of energy each way
• When is equilibrium reached in a reversible reaction?


  When reactions occur at the same rate in both directions
• What does the relative amounts of substances at equilibrium depend on?


  The conditions of the reaction
• What does Le Chatelier's principle state?

  The system responds to counteract changes
• What happens if the concentration of a reactant is increased?


  Equilibrium shifts towards the products
• What occurs if the concentration of a product is increased?


  Equilibrium shifts towards the reactants
• How does an increase in temperature affect equilibrium?


  Equilibrium moves towards the endothermic reaction
• What happens to equilibrium if temperature is decreased?


  Equilibrium moves towards the exothermic reaction
• How does temperature affect yield in exothermic and endothermic reactions?


  • Increase in temperature: Decreases yield of exothermic reaction, Increases yield of endothermic reaction
  • Decrease in temperature: Increases yield of exothermic reaction, Decreases yield of endothermic reaction
• What effect does an increase in pressure have on gaseous reactions?


  It favors the reaction with fewer molecules
• What happens to equilibrium if pressure is increased?


  Equilibrium shifts to the side with fewer moles
• What occurs if pressure is decreased in a reaction?


  Equilibrium shifts to the side with more moles
• How does pressure affect yield in reactions producing different volumes of gas?


  • Increase in pressure: Decreases yield if larger volume of gas produced, Increases yield if smaller volume of gas produced
  • Decrease in pressure: Increases yield if larger volume of gas produced, Decreases yield if smaller volume of gas produced