Theory
Esters can be made by a variety of reactions. The n-butyl acetate synthesis performed in this lab illustrates the most fundamental method of preparing esters, the Fischer esterification, corresponding to the general equation:
When a carboxylic acid and an alcohol are reacted together in this manner, a strong mineral acid (for example, H2SO4) is usually added to catalyze the reaction. R1 and R2 can be any organic group (alkyl, alkenyl, alkynyl, aryl) and they do not have to be the same. n-Butyl acetate is added to a variety of commercial products to create fruit flavours, especially apple, pear, and banana. This ester can also be used as a solvent for laquers, enamels, plastics, leather finishing, rubber and camphor.
The "Competition Experiment" section of this lab provides an example of another method of making esters - the reaction of alcohols with carboxylic acid chlorides.