How does sulfuric acid catalyze the preparation of esters?

1 Answer
Nov 17, 2015

Because it is very hygroscopic.

Explanation:

It litterally tears out #H_2O# combinations out of substances that do not even contain water, as long as it contains #H#'s and #O#'s. That's why sulfuric acid is so dangerous, as it rips away these #H#'s and #O#'s from all organic material, like skin...
As you might know, esterization is the combination of a alkanoic acid (#R_1-COOH#) with an alcohol (#R_2-OH#), where the #R#'s are the stuff that's attached to it.

It goes like this:

#R_1-COOH+R_2-OHrightleftharpoonsR_1-COO-R_2+H_2O#

This is an equilibrium reaction. If you remove one of the reaction products (in this case water) the reaction will shift to the right.

Note: in this view, sulfuric acid is not really a catalyst, because it changes (becomes more diluted) in the process.