Aldehydes and Ketones

Aldehydes definition: Are compounds containing a carbonyl group with at least one hydrogen attached to it.

Least organic compound: Methanal O=CH2

Ketones definition: Are compounds containing a carbonyl group with two hydrocarbons attached to it.

Least organic compound: Ethanone CH2-CH=O

Structure: They are organic compounds which incorporate a carbonyl group, that is functional, C=O. The carbon atom has two remaining bonds that may be occupied by hydrogen or arkyl or aryl substituents. If, at least one of these is hydrogen, it is an aldehyde. If neither is hydrogen, it is a ketone.

R1    .

 C = O

R2    .

Physical properties: They can H-bond with water, because they have an O atom. The small ones are freely soluble in water, but solubility falls with chain length. The reason for solubility is that although they can't H-bond with themselves, they can with water molecules.

IUPAC name	Molecular weight	Boiling point	Formula
Butane	58	0	CH3CH3CH2CH3
Propanol	60	97	CH3CH2CH2OH
Ethylmetherether	60	6	CH3-O-CH2CH3
Propanal	58	49	CH3CH2CH=O