What is the functional group of carboxylic acids?

The functional group of carboxylic acids is the carboxyl group, represented as -COOH.

Carboxylic acids are organic compounds that contain a carboxyl group. This functional group consists of a carbon atom double-bonded to an oxygen atom and also bonded to a hydroxyl group, hence the notation -COOH. The carbon atom is also attached to a hydrogen atom or a carbon chain. This unique structure is what gives carboxylic acids their specific properties.

The carboxyl group is polar due to the presence of the electronegative oxygen atoms. This polarity allows carboxylic acids to form hydrogen bonds with other molecules, making them generally more soluble in water than similar-sized hydrocarbons. The hydrogen in the -COOH group can also be donated as a proton (H+), making carboxylic acids acidic. This is where the name 'carboxylic acid' comes from.

Examples of carboxylic acids include acetic acid (found in vinegar), citric acid (found in citrus fruits), and lactic acid (found in sour milk and produced in our muscles during intense exercise). These compounds all share the common feature of the carboxyl functional group, which is responsible for their acidic properties.

In summary, the functional group of carboxylic acids is the carboxyl group, -COOH. This group is responsible for the characteristic properties of carboxylic acids, including their acidity and ability to form hydrogen bonds.