1. For a chemical reaction, the catalyst is needed in very small quantities. Generally, a pinch of catalyst is enough for a reaction in bulk.
2. There may be some physical changes, but the catalyst remains unchanged in mass and chemical composition in a chemical reaction.
3. A catalyst itself can not initiate a reaction. It means it can not start a reaction that is not taking place. But, if the reaction is taking place at a slow rate it can increase its rate.
4. A solid catalyst will be more effective if it is taken in a finely divided form.
5. A catalyst can catalyse a particular type of reaction, hence they are said to be specific in nature.
6. In an equilibrium reaction, the presence of catalyst reduces the time for attainment of equilibrium and here it does not affect the position of equilibrium and the value of the equilibrium constant.
7. A catalyst is highly effective at a particular temperature called as optimum temperature.
8. The presence of a catalyst generally does not change the nature of products
eg: 2SO2 + O2 → 2SO3
This reaction is slow in the absence of a catalyst, but fast in the presence if Pt catalyst.
