Final answer:
In Fischer esterification, the ester oxygen atom bonded to the carbonyl carbon and the alkyl group always originates from the alcohol. The correct answer is 1) The alcohol.
Step-by-step explanation:
In Fischer esterification, the ester oxygen atom bonded to the carbonyl carbon and the alkyl group always originates from the alcohol. During Fischer esterification, a carboxylic acid and an alcohol react in the presence of an acid catalyst. The alcohol donates the alkyl group, while the carboxylic acid provides the carbonyl carbon and the oxygen atom that becomes part of the ester.
For example, in the reaction between acetic acid and ethanol, the ethyl group (-CH2CH3) originates from ethanol, while the carbonyl carbon and the oxygen come from acetic acid, resulting in the formation of ethyl acetate. Naming of the ester also reflects this origin, with the alkyl group (from the alcohol) name coming first, followed by the carboxylate portion of the name (from the acid). Therefore, the correct answer is 1) The alcohol.