Chanteliers Principle

• What is Le Chatelier's principle about?

  It describes how the position of equilibrium in a reversible reaction is affected by changes in temperature, pressure, and concentration.
• What does the position of equilibrium refer to?

  It refers to the ratio of reactant particles to product particles when a reaction is at equilibrium.
• How do we describe the position of equilibrium if there are more reactants than products?

  We say that the equilibrium lies to the left.
• How do we describe the position of equilibrium if there are more products than reactants?

  We say that the equilibrium lies to the right.
• What happens to the position of equilibrium when conditions of a reversible reaction change?

  The position of equilibrium shifts to counteract the change.
• How does a decrease in temperature affect the position of equilibrium in an exothermic reaction?


  • The equilibrium shifts in the exothermic direction.
  • This results in more product formation.
• What is the overall energy change of the forward reaction in the production of ammonia from nitrogen and hydrogen?

  The overall energy change is -92 kilojoules per mole.
• What does a negative energy change indicate about a reaction?

  It indicates that the forward reaction is exothermic and releases energy.
• What happens to the position of equilibrium when the temperature is increased in an exothermic reaction?

  • The equilibrium shifts to the left.
  • This results in more reactant formation.
• How does an increase in pressure affect the position of equilibrium in a reaction?

  • The equilibrium shifts to the side with fewer molecules.
  • This reduces the pressure in the system.
• What happens to the position of equilibrium if the pressure is decreased?

  The equilibrium shifts to the side with more molecules to increase pressure.
• How does adding more nitrogen to a sealed container affect the equilibrium position?

  • The equilibrium shifts to the right.
  • This results in the formation of more ammonia.
• What is the effect of increasing the concentration of a reactant on the position of equilibrium?

  The equilibrium shifts to the opposite side to counteract the change.