WAEC Chemistry 2024 Paper

Concept:Alkanoic acids are carboxylic acids, and their characteristic functional group is the carboxyl group.Explanation:An alkanoic acid contains the carboxyl functional group, written as $-\mathrm{COOH}$.This group consists of a carbonyl group, $\mathrm{C=O}$, and a hydroxyl group, $-\mathrm{OH}$, attached to the same carbon atom.The presence of $-\mathrm{COOH}$ is what makes a compound an alkanoic acid.Option B, $-\mathrm{OH}$, is an alcohol group.Option C, $-\mathrm{COOR}$, is an ester group.Option D, $-\mathrm{CHO}$, is an aldehyde group.Hence, the functional group present in alkanoic acid is $-\mathrm{COOH}$.Answer:A. $-\mathrm{COOH}$