How do you identify the functional group in an organic molecule?

You identify the functional group in an organic molecule by examining its structure for specific atom arrangements.

Functional groups are specific groupings of atoms within molecules that have their own characteristic properties, regardless of the other atoms present in the molecule. They are the reactive parts of molecules and are primarily responsible for the chemical behaviour of organic compounds.

To identify a functional group, you need to look for specific arrangements of atoms. For example, an alcohol functional group consists of a hydrogen atom bonded to an oxygen atom, which is in turn bonded to a carbon atom. This is represented as -OH in structural formulas. Similarly, a carboxylic acid functional group is represented as -COOH, where a carbon atom is double-bonded to an oxygen atom and single-bonded to a hydroxyl group (-OH).

Other common functional groups include aldehydes (-CHO), ketones (-CO-), amines (-NH2), and ethers (-O-). Each of these groups has a unique structure that you can identify in the molecule.

It's important to remember that a molecule can have more than one functional group. For example, amino acids, the building blocks of proteins, contain both an amine (-NH2) and a carboxylic acid (-COOH) functional group.

In summary, identifying functional groups involves recognising specific patterns of atoms in the structure of an organic molecule. This is a key skill in organic chemistry, as the functional groups largely determine the properties and reactions of the molecule.