Chapter 11 Introduction to Organic Chemistry: Alkanes 11.5 Functional Groups

Elements in Organic Compounds In organic molecules, C atoms form bonds mostly with H and other C atoms sometimes with atoms of O, S, N, P, and halogens F, Cl, and Br

Functional Groups Functional groups are a characteristic feature of organic molecules that behave in a predictable way are composed of an atom or group of atoms are groups that replace a H in the corresponding alkane provide a way to classify families of organic compounds

Some Functional Groups

Alkenes and Alkynes Alkenes contain a double bond between adjacent carbon atoms. Alkynes contain a triple bond. Aromatic compounds contain a benzene ring.

Alcohols and Ethers An alcohol contains the hydroxyl (–OH) functional group. In an ether, an oxygen atom is bonded to two carbon atoms (–C–O–C–).

Thiols In a thiol, the functional group –SH is bonded to a carbon atom.

Aldehydes and Ketones An aldehyde contains a carbonyl group (C=O), which is a carbon atom with a double bond to an oxygen atom, attached to at least one hydrogen. In a ketone, the carbon of the carbonyl group is attached to two other carbon atoms.

Carboxylic Acids and Esters Carboxylic acids contain the carboxyl group, which is a carbonyl group attached to a hydroxyl group. An ester contains the carboxyl group between carbon atoms.

Amines and Amides In an amine, the functional group is a nitrogen atom. In an amide, the hydroxyl group of a carboxylic acid is replaced by a nitrogen group.

Learning Check Classify each of the following as alcohol, ether, aldehyde, ketone, carboxylic acid, ester, or amine.

Solution Classify each of the following as alcohol, ether, aldehyde, ketone, carboxylic acid, ester, or amine.