Final answer:
A functional group in an organic compound is a group of atoms responsible for the characteristic chemical reactions of the molecule. Functional groups are structural units that define the chemical behavior and reactions of compounds, indicated by specific prefixes or suffixes in nomenclature based on their hierarchy.
Step-by-step explanation:
A functional group in an organic compound is a specific group of atoms within a molecule that is responsible for certain characteristic chemical reactions. Functional groups are like the active sites that give the molecule its unique properties and tendencies to react in certain ways. Here are some examples of functional groups:
- Ketone: characterized by the -CO- group where two carbon groups are attached to the carbonyl carbon atom.
- Acid Anhydride: comes from two carboxylic acid groups losing water and is characterized by the anhydride bond, -OC(O)C(O)O-
- Aldehyde: contains the -CHO group, with at least one hydrogen atom attached to the carbonyl carbon atom.
- Amide: contains the -CONH2 group, featuring a carbonyl connected to a nitrogen atom.
- Alcohol: characterized by the -OH group, a covalently bonded oxygen and hydrogen atom.
The presence and position of functional groups within a molecule determine the molecular structure and the chemical reactivity under certain conditions. In the nomenclature of organic compounds, these groups are indicated by prefixes (for lower priority) or suffixes (for higher priority) relative to other functional groups present.