Concentration and reversible reactions

• What should you be able to describe by the end of the video?

  The effect of concentration on equilibrium
• What happens at equilibrium in a reversible reaction?

  Forward and reverse reactions occur at the same rate
• What is the term for the point where reactions occur at the same rate?

  Equilibrium
• What does a system at equilibrium do when conditions change?

  It responds to counteract the change
• What principle describes the response of a system at equilibrium to changes?

  Le Chatelier's principle
• What happens when the concentration of a reactant is increased in a reversible reaction at equilibrium?

  • The system is no longer at equilibrium
  • More product is formed until equilibrium is restored
• What happens if we increase the concentration of $NO_2$ in the reaction forming $N_2O_4$?


  More $N_2O_4$ will be formed
• What occurs when the concentration of $N_2O_4$ is decreased?


  More $NO_2$ will react to form $N_2O_4$
• What happens if we increase the concentration of $N_2O_4$ again?


  More $NO_2$ will be formed
• What are the effects of changing concentration on reversible reactions at equilibrium?

  • Increasing reactant concentration shifts equilibrium to products
  • Decreasing product concentration shifts equilibrium to reactants
  • Changes cause the system to adjust until equilibrium is restored
• Where can students find more questions on the effect of concentration on reversible reactions?

  In the revision world walk
• What should students be able to describe after watching the video?

  The effect of changing concentration on equilibrium