A type of chemical reaction in which ester molecules are broken to create a functional group of carboxylic acid and alcohol is called:

Saponification is a chemical reaction which involves the breaking down of ester molecules in order to create a functional group of carboxylic acid and alcohol.
A saponification reaction produces alcohol and a carboxylic acid salt when acidic or necessary conditions exist. In most cases, "saponification" involves consuming fat or grease with a metallic base to form soap. When ethanol and alcohol are combined, esters are formed. There is sulphuric acid present in the solution. $C{H}_{3}C{H}_2\mathit{OH}+C{H}_3\mathit{COOH }+\mathit{conc}. H_2{\mathit{SO}}_4\to \mathit{ C}{H}_3\mathit{COO}{C}_2{H}_5+H_{2}O$