Catalysts
- Catalysts are substances which speed up the rate of a reaction without themselves being altered or consumed in the reaction
- The mass of a catalyst at the beginning and end of a reaction is the same and they do not form part of the equation
- Normally only small amounts of catalysts are needed to have an effect on a reaction
- Different processes require different types of catalysts but they all work on the same principle of providing an alternate route for the reaction to occur
- They do this by lowering the activation energy required, hence providing a reaction pathway requiring less energy
- Catalysis is a very important branch of chemistry in commercial terms as catalysts increase the rate of reaction (hence the production rate) and they reduce energy costs
A catalyst lowers the activation energy of a reaction by providing an alternative reaction pathway
Exam Tip
Although catalysts are not part of the overall reaction, you may see them written over the arrow in reaction equations in the same way you can add reaction conditions above or below the arrow.
