Catalysts (Oxford AQA IGCSE Chemistry)

Revision Note

Catalysts

  • Catalysts provide the reactants with a different pathway for a chemical reaction that has a lower activation energy

  • By lowering the activation energy, Eagreater proportion of molecules in the reaction mixture have sufficient energy for an effective collision

  • As a result of this, the rate of the catalysed reaction is increased compared to the uncatalysed reaction

Energy level diagram for an exothermic reaction with and without a catalyst

exo-reaction-profile-with-catalyst

A catalyst lowers the activation energy

Examiner Tips and Tricks

You are expected to be able to draw a curve for the activation energy with a catalyst on a provided energy level diagram.

Make sure that the curve starts and finishes in the same place as the original curve but is lower.

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