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• Reversible Reaction - the products can react with each other to produce the original reactants
• Dynamic Equilibrium - the forward/backward reactions are happening at the same time/rate and concentrations of reactants/products have reached an unchangeable balance

  This can only happen if a reversible reaction happens in a closed system
• The Haber Process - nitrogen and hydrogen react to form ammonia:

  • nitrogen from the air (78%)
  • hydrogen from natural hydrocarbons (natural gas and crude oil)
  • conditions include: 450 'C, 200 atmospheres pressure and an iron catalyst
• Le Chatelier's Principle - if there is a change in concentration, pressure or temperature then the equilibrium position will move to counteract the change
• Temperature - exothermic in one direction (ammonia) and endothermic in the other (reactants)

  • decreasing temperature will make the equilibrium favour the exothermic direction to produce heat (ideal for Haber Process)
  • increasing temperature will make the equilibrium favour the endothermic direction to absorb heat
• Pressure - only effects equilibria involving gases (ammonia gas)

  • increasing pressure will make the equilibrium favour the side with fewer moles to reduce pressure (ideal for Haber Process)
  • decreasing pressure will make the equilibrium favour the side with more moles to increase pressure
• Concentration

  • increasing reactant concentration will create more product to use up reactants (ideal for Haber Process)
  • increasing product concentration will create more reactants
  • decreasing concentration has the opposite effect