What are the different ways (variations) of driving and controlling an esterification reaction and how do they drive the reaction? What have chemists discovered to tweak, drive, and control it?

Answer 1

Esterifications are generally endothermic reactions. This means they require heat. Heating an esterification reaction (as predicted by Le Chatelier's Principle) will push the equilibrium position toward the products. It will also reduce the amount of time it takes for the reaction to reach equilibrium.

Because esterification is, indeed, an equilibrium process, you can also push the reaction to the right by increasing the concentrations of either the carboxylic acid or the alcohol. (Note: Adding more of the acid catalyst will not shift the equilibrium position. It will only effect how quickly the reaction reaches equilibrium). Alternatively, you can remove water from the reaction through the use of a Dean-Stark trap, or something of the like.

In certain esterification reactions, the carboxylic acid and alcohol may not mix very well. For instance, if you wanted to make cyclohexyl benzoate, you'd react benzoic acid (white powder) and cyclohexanol (viscous liquid). Benzoic acid does not disolve in cyclohexanol very well, so a co-solvent might be used to help facilitate the reaction.

Hope this helped.