Question

Write a balanced equation for: Acetic acid is warmed with ethanol in the presence of conc.${{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}$.

Answer 1

Hint: Esterification is the reaction of alcohol with acid forms an ester by loss of a water molecule. It is a condensation reaction.

Complete step by step answer:
When acetic acid is warmed with ethanol in the presence of conc.${{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}$,ethyl acetate is formed by losing a molecule of water. Ethyl acetate, \[{\text{C}}{{\text{H}}_{\text{3}}}{\text{COO}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}\] is an ester. This reaction to form an ester is called Fischer esterification which happens through acid catalysis. This reaction is also used as a test for ethanoic acid. The resultant compound has a sweet smell.
\[{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{\text{OH + C}}{{\text{H}}_{\text{3}}}{\text{COOH}}\xrightarrow{{{{\text{H}}^{\text{ + }}}}}{\text{C}}{{\text{H}}_{\text{3}}}{\text{COO}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}} + {{\text{H}}_{\text{2}}}{\text{O}}\]
The above reaction is a chemically balanced equation.
The above reaction can take place even in the presence of base which is called a saponification reaction. This reaction is used in industries to manufacture soaps.

Additional information:
Due to the fragrance of esters they are used in perfumes, food flavourings, and cosmetics. Few naturally occurring esters are found in the backbone of DNA and in pheromones. The polymerisation of esters leads to polyesters that are used in the production of plastics. Since the esterification reaction is reversible, a 1:1 mixture of the carboxylic acid and the alcohol will reach equilibrium with about 70% yield of the ester. However, as with any equilibrium process, the reaction can be driven in one direction by changing the concentration, pressure, temperature, or volume of the reagents. This change causes the reaction to adjust to a new equilibrium to counteract the change, which is the basis of Le Chatelier’s principle.

Note:
The reversible reaction of forming alcohol and acid from ester is known as alkaline or acid hydrolysis of ester.
\[{\text{C}}{{\text{H}}_{\text{3}}}{\text{COO}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}} + {{\text{H}}_{\text{2}}}{\text{O}}\xrightarrow{{{{\text{H}}^{\text{ + }}}}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{\text{OH + C}}{{\text{H}}_{\text{3}}}{\text{COOH}}\]