Explain in detail what do you understand by catalyst, what makes them so useful and give two example of catalytic processes including the name catalyst used.

Catalyst are chemical or biological substances that speeds up the rate of reaction without being used up in the overall process. It provides an alternative route for a reaction occur with a lower activation energy and this property is highly valued by industries. It is because the same reaction requiring high operating temperature and pressure can be carried out at lower temperature and pressure in the presence of catalyst. This ensures a safe working environment and lower operating cost for a industry. Iron catalyst is in Haber process and a yeast called Saccharomyces cerevisiae is used in production of ethanol (beer).