Equilibrium

• When both forward and reverse reactions occurring simultaneously have the same rate of reaction. There is no change in the amount of products or reactants​

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Equilibrium constant (Kc)​

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Change in conditions affecting equilibrium constant and position

• Increase in concentration of reactants

  • Position:​ favours the RHS

  • Equilibrium constant: No change

• Increase in concentration of products

  • Position:​ favours the LHS

  • Equilibrium constant: No change

• Increase in pressure

  • Position:​  favours the side with least volume

  • Equilibrium constant: No change

• Decrease in pressure

  • Position:​ favours the side with most volume

  • Equilibrium constant: No change

• Increase in temperature

  • Position:​ favours the endothermic reaction

  • Equilibrium constant: May change

• Decrease in temperature

  • Position:​ favours the exothermic reaction

  • Equilibrium constant: May change

• Addition of catalyst

  • Position:​ No change, the system will reach equilibrium faster; as both reates increase equally

  • Equilibrium constant: No change

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Reaction quotient (Q)

Definition: ratio of concentration of products to reactants

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Q=Kc

• The system is at equilibrium

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Q>Kc

• Concentration of products is greater than reactants

• Reverse reaction is favoured until equilibrium

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Q<Kc

• Concentration of reactants is greater than products

• Forward reaction is favoured until equilibrium

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