Catalyst

[Jerryt12]

How do scientists know which catalyst to use in different reactions?

 

For example, how do scientists know to use acid for esterification?

[jdurg]

Because many, many, many, MANY scientists have done the reactions before and the key part of scientific research is documenting everything you do. Therefore, all they have to do is look it up in a book (if it's not something that they've already memorized) and they have the proper catalyst to use?

 

Now how did that particular catalyst get discovered in the first place? Experimenting. For millenia scientists have tried using different chemicals to speed up the rates of reactions. Early on, it wasn't exactly safe or wise, but they would just take a random chemical and throw it into a mixture to see if it had any effect. Nowadays, the structure of the chemicals in use, the reaction pathways, and various other characteristics about the reaction itself are used to determine beforehand if a catalyst exists for that reaction and if it would work well.

[Mr Skeptic]

A few of the catalysts can be predicted, especially the acid or base catalysts, from the reaction you are trying to do. Oftentimes the catalysts just seem random, although I suppose a supercomputer and a physical model might predict them. Anyhow, looking it up is probably the best method.

[Horza2002]

The simple ones like using acids and bases can be epeccted if you look at the mechanism. Others have been designed to work (e.g. Wilkinsons catalyst)