Rates of reaction - (CCEA)Effect of catalysts

The rate of a reaction can be increased by adding a suitable catalyst. A catalyst is a substance which increases the rate of a chemical reaction but it is not used up (remains chemically unchanged at the end).

Only a very small amount of catalyst is needed to increase the rate of reaction between large amounts of reactants.

A catalyst is specific to a particular reaction:

• different catalysts catalyse different reactions
• not all reactions have suitable catalysts