Reversible Reactions

• What is a reversible reaction?


  A reaction that can go backwards and forwards
• What does this show?

  A and B can react to produce C and D

  C and D can react to produce A and B

  
• What does ⇌ represent in a reaction?


  A reversible reaction
• How can the direction of reversible reactions be changed?


  By changing conditions
• What happens in a reversible reaction?


  The products can react to produce the original reactants.
• What happens when solid ammonium chloride is heated?


  It decomposes to produce ammonia and hydrogen chloride gas.
• What occurs when ammonia reacts with hydrogen chloride gas?


  It produces clouds of white ammonium chloride.
• What is the chemical equation for the decomposition of ammonium chloride?


  NH₄Cl(s) ⇌ NH₃(g) + HCl(g).
• How can the direction of reversible reactions be changed?


  By changing the conditions.
• What is the relationship between exothermic and endothermic reactions in reversible reactions?


  If a reversible reaction is exothermic in one direction, it is endothermic in the opposite direction.
• What can be said about the energy in exothermic and endothermic reactions?


  The amount of energy given out in the exothermic reaction is the same as the amount of energy taken in during the endothermic reaction.
• What are the key characteristics of reversible reactions?


  • Can proceed in both forward and backward directions
  • Products can revert to original reactants
  • Represented by a double arrow (⇌)
  • Direction can be changed by altering conditions
  • Energy changes are equal in exothermic and endothermic processes