Reversible reactions

• What is a reversible reaction?

  A reaction that can proceed in both directions
• What is equilibrium in a reversible reaction?

  When forward and reverse reactions occur at the same rate
• What happens to energy in an endothermic reaction?

  Energy is absorbed from the surroundings
• What happens to energy in an exothermic reaction?

  Energy is released into the surroundings
• What is the effect of heating on the reaction of ammonium chloride?

  It produces ammonia and hydrogen chloride
• How does cooling affect the reaction of ammonia and hydrogen chloride?

  It reforms ammonium chloride from the products
• What color is hydrated copper sulfate?

  Blue
• What color is anhydrous copper sulfate?

  White
• What happens when hydrated copper sulfate is heated?

  It forms anhydrous copper sulfate and water
• What is the energy change in the forward reaction of hydrated copper sulfate?

  The forward reaction is endothermic
• What is the energy change in the reverse reaction of anhydrous copper sulfate?

  The reverse reaction is exothermic
• What is the relationship between endothermic and exothermic reactions in reversible reactions?

  • Exothermic in one direction
  • Endothermic in the opposite direction
  • Same amount of energy is transferred
• Why is the copper sulfate reaction important for exams?

  It is often asked in exams
• What happens in a sealed container during a reversible reaction?

  Forward and reverse reactions reach equilibrium
• What is the definition of equilibrium in chemistry?

  Point where forward and reverse reactions occur at the same rate
• What are the key facts about energy changes in reversible reactions?

  • Exothermic in one direction
  • Endothermic in the opposite direction
  • Same energy amount transferred in both directions