Which property of sulfuric acid makes it suitable to use as a catalyst for the preparation of esters?

Esterification is the reaction of an alcohol with an acid to produce an ester and water. When the acid used in the reaction is carboxylic acid, the reaction is sometimes called a Fischer-Speier esterification.

An ester has a functional group similar to carboxylic acid, except that the H in the –COOH group is replaced by a hydrocarbon.

Normally esterification is slow and reversible, making the production of significant amounts of ester difficult.

The addition of sulfuric acid (`~H_2SO_4` ) as a catalyst, increases the rate of the reaction. Sulfuric acid is a catalyst because it is regenerated and not used up in the reaction.

Sulfuric acid is a good catalyst for this reaction because it is a strong proton donor. It is also a good dehydrating agent which is helpful in sequestering some of the water produced in the reaction.