Specification Point 3.21C (Paper 2C Only):
Understand why a catalyst does not affect the position of equilibrium in a reversible reaction
Catalyst: A substance that increases the rate of a reaction, but is chemically unchanged at the end of the reaction.
Position of equilibrium: the concentration of reactant and products at the equilibrium state.
- When the position of equilibrium shifts to the left, it means the concentration of reactant increases.
- When the position of equilibrium shifts to right, this means the concentration of product increases.
Effect of Catalyst on Equilibrium Position
Effect of catalyst on equilibrium position:
- A catalyst will not affect the position of equilibrium
- This is because the catalyst increases the rate of both the forward and backward reactions by the same amount (by providing an alternative pathway requiring lower activation energy)
- As a result, the concentration of reactants and products is nevertheless the same at equilibrium as it would be without the catalyst
The effect of catalyst on equilibrium position
Aiming for a Level 9?
See if you’ve got what it takes. Test yourself with our topic questions.
Jamie got a First class degree in Chemistry from Oxford University before going on to teach chemistry full time as a professional tutor. He’s put together these handy revision notes to match the Edexcel IGCSE Chemistry specification so you can learn exactly what you need to know for your exams.
More Edexcel IGCSE (9-1) Chemistry Revision Resources