Question

Word equation of ethanol + butanoic acid.

Answer 1

Esterification is an example of a nucleophilic addition mechanism where the ester is formed when the alcohol molecule attaches itself to the carboxy acid. Moreover, this nucleophilic addition mechanism will be easy when the alkyl group of the alcohol is smaller because the larger alkyl groups would create problems in the nucleophilic addition of the alcohol to the carboxyl group.

Complete answer:
Usually carboxylic acids react with alcohol in the presence of an acid catalyst producing an ester along with water as a side product. In this mechanism ${H^ + }$ion from the acid, catalyst protonated the carbonyl oxygen because of which the carbon atom becomes positively charged, and therefore, it undergoes nucleophilic attack by the alcohol molecule thereby leading to the formation of ester. This mechanism is called Fisher esterification or simply esterification.
Therefore, when Ethanol with chemical formula ${C_2}{H_6}O$ having alcohol as a functional group is treated with butanoic acid with chemical formula ${C_4}{H_8}{O_2}$ with carboxylic acid as a functional group in presence of an acid catalyst produces ethyl butanoate with chemical formula ${C_6}{H_{12}}{O_2}$ and water.
Hence, the word equation for the reaction of ethanol with butanoic acid is as follows:
Ethanol + Butanoic acid $\to$ Ethyl butanoate + water

Note:
Esters can be prepared by the method of Fisher esterification where alcohol reacts with a carboxylic acid in the presence of an acid catalyst to produce ester along with water. The process of esterification is reversible in nature. Moreover, esterification involves the cleavage of the O-H bond present in the alcohols and the C-OH bonds of the carboxylic acid.