1.6 Equilibria, Kc

• Dynamic equilibrium

  forward and backwards reaction happens at the same rate

  conc of reactants and products stays constant

  (happens in a closed system)
• Le Chatalier's principle

  if a reaction at equilibrium is subjected to change, the position of equilibrium will move to counteract the change
• position of equilibrium moves left

  backwards reaction is faster -> more reactants
• position of equilibrium moves right

  forwards reaction is favoured -> more products
• effect of changing temp on equilibrium

  increasing temp -> favours endothermic reaction

  decreasing temp -> favours exothermic reaction
• effect of changing conc on equilibrium

  increasing conc of reactants -> favours forwards reaction - making more products

  increasing conc of products -> favours backwards reaction - more reactants
• effect of changing pressure on equilibrium

  increasing -> moves to side with fewer molecules

  decreasing -> moves to side with more molecules
• effect of catalyst on equilibrium position


  doesnt affect the position but allows equilibrium to be reached faster
• Kc represents the equilibrium constant in reversible reactions
• only a change in temp affects Kc - change in equilibrium position results in diff concs of reactants and products