- Aldehyde Group :
It consists of 1 carbon, 1 hydrogen and 1 oxygen atom joined together.
General formula --- CnC2nO
Methanal - HCHO --- formaldehyde
Ethanal - CH3CHO ---- acetaldehyde
Propanal – CH3CH2CHO --- propionaldehyde
Butanal - CH3CH2CH2CHO
- Ketone Group :
It consists of 1 carbon and 1 oxygen atom. A ketone group must contain at least 3 carbon atoms.
General formula -- CnC2nO
Propanone - CH3COCH3 ---- acetone ( simplest ketone)
Butanone - CH3COCH2CH3
Pentanone - CH3COCH2CH2CH3
- Carboxylic Acid Group :
It is present in Methanoic acid ( formic acid) - HCOOH
Ethanoic Acid ( acetic acid) - CH3−COOH
Propionic Acid - C2H5COOH or CH3CH2COOH
They are also called Organic acids and contain carbon , hydrogen and oxygen.
- Alkene Group :
It is a Carbon – carbon double bond.
Ethene - CH2 = CH2
Propene - CH3− CH = CH2
- Alkyne Group : −C≡C−
Ethyne - CH≡CH
Propyne - CH3−C≡CH