CBSE Class 10 Science 2017 · Paper 31/2 · Question 10

Esterification: a carboxylic acid reacts with an alcohol in the presence of an acid catalyst (a few drops of concentrated sulphuric acid) to form a sweet-smelling compound called an ester, and water. For ethanoic acid and ethanol: ${\text{CH}}_3\text{COOH}+{\text{CH}}_3{\text{CH}}_2\text{OH}\stackrel{\text{conc. }{\text{H}}_2{\text{SO}}_4}{\to }{\text{CH}}_3{\text{COOCH}}_2{\text{CH}}_3+{\text{H}}_2\text{O}$ — ethanoic acid and ethanol give ethyl ethanoate and water. Activity: take $1$ mL of ethanol (absolute alcohol) and $1$ mL of glacial acetic acid in a test tube and add a few drops of concentrated sulphuric acid. Warm the test tube in a water bath for at least five minutes. Pour the contents into a beaker containing $20$–$50$ mL of water and smell the mixture. A sweet, fruity smell shows that an ester has been formed.