Reversible reactions and Equilibrium

• What are reversible reactions?

  Reactions that can proceed in both directions
• What does the term equilibrium refer to in reversible reactions?

  It is the state where reactants and products' concentrations remain constant
• What symbol indicates a one-way reaction?

  An arrow pointing to the right
• What does a double arrow in a reaction signify?

  The reaction is reversible
• What is the forward reaction in the context of ammonium chloride?

  Ammonium chloride breaks down into ammonia and hydrogen chloride
• What is the backward reaction in the context of ammonium chloride?

  Ammonia and hydrogen chloride combine to reform ammonium chloride
• How do the rates of forward and backward reactions change over time?

  The forward reaction slows down while the backward speeds up
• What happens when the forward and backward reactions reach the same speed?

  The reaction is at equilibrium
• What does it mean when a reaction is at equilibrium?

  Concentrations of reactants and products remain constant
• Can the concentrations of reactants and products be the same at equilibrium?

  No, they can be different
• What does it mean if the equilibrium lies to the right?

  There are more products than reactants
• What does it mean if the equilibrium lies to the left?

  There are more reactants than products
• How can the position of equilibrium change?

  By altering the conditions of the reaction
• What effect does adding heat have on the position of equilibrium?

  It encourages the forward reaction
• What happens to the position of equilibrium when the reaction is cooled?

  It shifts back to the left
• What is required for equilibrium to be reached in a reversible reaction?

  A closed system where reactants and products cannot escape
• What is the nature of reversible reactions in terms of energy?

  One direction is exothermic, the other is endothermic
• What does hydrated mean in chemistry?

  Water is present in the compound
• What does anhydrous mean in chemistry?

  No water is present in the compound
• What happens when hydrated copper sulfate is heated?

  It drives the reaction to form anhydrous copper sulfate
• What occurs when water is added to anhydrous copper sulfate?

  It drives the backward reaction to reform blue crystals
• What energy change occurs during the backward reaction of hydrated copper sulfate?

  It re-releases the energy absorbed in the forward reaction
• What are the key characteristics of reversible reactions?

  • Indicated by a double arrow
  • Can proceed in both forward and backward directions
  • One direction is exothermic, the other is endothermic
  • Equilibrium is reached when rates are equal
  • Concentrations of reactants and products remain constant
• What factors can affect the position of equilibrium?


  • Temperature changes
  • Concentration of reactants or products
  • Pressure changes in gaseous reactions
• What is the significance of a closed system in reversible reactions?

  • Prevents escape of reactants and products
  • Allows equilibrium to be reached
  • Ensures consistent reaction conditions
• Reversible reactions definition

  In a reversible reaction the amount of Energy given off in the reaction will exactly equal the amount of energy taken in by the reverse reaction. This is due to the conservation of energy.
• what is a dynamic equilibrium?

  a state of balance between continuing processes
• concentration and equilibrium

  if you disturb a reaction at equilibrium, the equilibrium will shift to minimize the disturbnace.
• dynamic equilibrium and temperature

  increasing temperature will speed up the rate of the backwards reaction a lot more than the forward reaction as it is endothermic and needs more energy to get going