Functional groups: the part that gives a molecule its behaviour

0:00Organic molecules are built on carbon chains, so what gives each one its behaviour?

0:07Ethane is a hydrocarbon: it has only carbon and hydrogen atoms.

0:13Picture swapping one hydrogen for O H, an oxygen joined to a hydrogen. Ethane becomes ethanol.

0:22This O H, a hydroxyl group, is a functional group: a small group of atoms that sets how a molecule reacts.

0:30Ethanol is an alcohol. Alcohols have a hydroxyl group, and their names end in O L.

0:38Ethanoic acid, the acid in vinegar, has a carboxyl group, C O O H. Carboxylic acid names end in O I C acid.

0:49Methanal has an aldehyde group, C H O: a carbon double bonded to oxygen, with a hydrogen. Aldehyde names end in A L.

1:00Propanone, in many nail polish removers, has a carbon double bonded to oxygen between two carbons. It is a ketone, ending in O N E.

1:10Methyl ethanoate has a C O O group between two carbons, so it is an ester. Many esters smell fruity.

1:19An ether has an oxygen atom between two carbons, as in methoxymethane.

1:25Many amines, like methanamine, have an N H 2 group: a nitrogen with two hydrogens.

1:33A halide has a halogen atom, such as chlorine, in place of a hydrogen, as in chloromethane.

1:40Methanoic, ethanoic and propanoic acid all have a carboxyl group, so they react alike: each fizzes with baking soda.

1:50The functional group is the part of a molecule that sets its family, its reactions and its name ending.