Step 1: Understand what a functional group is. A functional group is a specific group of atoms within a molecule that is responsible for the characteristic chemical reactions of that molecule.
Step 2: Identify the specific functional group for carboxylic acids. Carboxylic acids have a unique group called the carboxyl group.
Step 3: Recognize the structure of the carboxyl group. The carboxyl group is written as -COOH.
Step 4: Conclude that the functional group of carboxylic acids is the carboxyl group (-COOH).
