Explanation

• Among the given options, the process of tautomerism is exemplified by the first reaction: CH3COOH + C2H5OH ⇌ CH3COOC2H5 + H2O.
• Tautomerism involves the rearrangement of bonds within a molecule, resulting in the formation of structural isomers called tautomers, which readily interconvert.
• In this reaction, the acetic acid (CH3COOH) and ethanol (C2H5OH) undergo tautomerism to form ethyl acetate (CH3COOC2H5) and water (H2O).