Organic Chemistry MCAT Practice Exam

What occurs during the saponification process of ester hydrolysis?

1. Formation of a carboxylate anion

2. Formation of an ether

3. Elimination of an alcohol

4. Reduction of an aldehyde

The correct answer is: Formation of a carboxylate anion

During the saponification process of ester hydrolysis, a carboxylate anion is indeed formed. Saponification typically involves the reaction of an ester with a strong base, such as sodium hydroxide (NaOH). In this reaction, the ester undergoes hydrolysis, which results in the cleavage of the ester bond. As the ester is hydrolyzed, it reacts with the hydroxide ions from the base. This leads to the formation of an alcohol and a carboxylate salt. The carboxylic acid part of the ester is converted into its dissociated form, which is the carboxylate anion. This process is a key reaction in the production of soap from fats and oils, which are esters of fatty acids and glycerol. The formation of the carboxylate anion is crucial as it is the salt that constitutes the soap, providing the surfactant properties that enable the cleaning action.