Carboxyl Group Definition and Examples

What Is the Carboxyl Group in Chemistry?

The formula for the carboxyl functional group is RCOOH.
The formula for the carboxyl functional group is RCOOH. De.Nobelium

Carboxyl Group Definition

The carboxyl group is an organic functional group consisting of a carbon atom double bonded to an oxygen atom and single bonded to a hydroxyl group. Another way to view it is as a carbonyl group (C=O)
that has a hydroxyl group (O-H) attached to the carbon atom.

The carboxyl group is commonly written as -C(=O)OH or -COOH.

Carboxyl groups ionize by releasing the hydrogen atom from the -OH group.

The H+, which is a free proton, is released. Thus, carboxyl groups make good acids. When hydrogen leaves, the oxygen atom has a negative charge, which it shares with the second oxygen atom on the group, allowing the carboxyl to remain stable even when oxidized.

Also Known As: The carboxyl group is sometimes referred to as the carboxy group, carboxyl functional group or carboxyl radical.

Carboxyl Group Example

Probably the best known example of a molecule with a carboxyl group is carboxylic acid. The general formula of carboxylic acid is R-C(O)OH, where R is any number chemical species. Carboxylic acids are found in acetic acid and the amino acids that are used to build proteins.

Because the hydrogen ion detaches so readily, the molecule is most commonly found as a carboxylate anion, R-COO-. The anion is named using the suffix -ate. For example, acetic acid (a carboxylic acid) becomes the acetate ion.

Format
mla apa chicago
Your Citation
Helmenstine, Anne Marie, Ph.D. "Carboxyl Group Definition and Examples." ThoughtCo, Sep. 3, 2017, thoughtco.com/definition-of-carboxyl-group-and-examples-604879. Helmenstine, Anne Marie, Ph.D. (2017, September 3). Carboxyl Group Definition and Examples. Retrieved from https://www.thoughtco.com/definition-of-carboxyl-group-and-examples-604879 Helmenstine, Anne Marie, Ph.D. "Carboxyl Group Definition and Examples." ThoughtCo. https://www.thoughtco.com/definition-of-carboxyl-group-and-examples-604879 (accessed April 20, 2018).