Functional groups

04 Carbon and its compound

  • Functional group is an ‘atom’ or ‘a group of atoms’ which makes a carbon compound (or organic compound) reactive and decides its properties (or functions).

Alcohol Group:-

  • Alcohol group is made up of one oxygen atom and one hydrogen atom joined together:
  • The examples of compounds containing alcohol group are : methanol, CH3OH, and ethanol, C2H5OH.

Aldehyde Group

  • It consists of one carbon atom , one hydrogen atom and one oxygen atom joined together:
  • The aldehyde group is sometimes called formyl group.

Ketone Group:

  • It consists of one carbon atom and one oxygen joined together:
  • Propanone is an example of ketone group


  • Haloalkane is obtained when one hydrogen atom of an alkane replaces a halogen atom. Haloalkane is also called halogenoalkane .
  • For example, when one hydrogen atom of methane is replaced by a chlorine atom, we get chloromethane:

Naming of Haloalkanes

  • CH3Cl – IUPAC name: Chloromethane           Common name = Methyl chloride
  • C2H5Cl- IUPAC name: Chloroethane             Common name = ethyl chloride.


  • Alcohol group is the hydroxyl group attached to a carbon atom.
  • For example, by replacing one hydrogen atom of methane by a hydroxyl group (OH) we get an alcohol called methyl alcohol or methanol:
CH4 Replace H by OHCH3OH

(Methane)                       (Methyl Alcohol)

Naming of Alcohols

  • CH3OH – IUPAC name: Methanol            Common name = methyl alcohol
  • C2H5OH – IUPAC name: Ethanol              Common name = ethyl alcohol


  • Aldehydes are the carbon compounds (or organic compounds) containing an aldehyde group (- CHO group) attached to a carbon atom.
  • The two simple aldehydes are formaldehyde, HCHO (which is also called methanol) and acetaldehyde, CH3CHO (which is also called ethanal).

Naming of Aldehydes

  • HCHO – IUPAC name: Methanal             Common name = formaldehyde.
  • CH3CHO – IUPAC name: Ethanal            Common name: acetaldehyde


  • Ketones are the carbon compounds (or organic compounds) containing the ketone group, – CO – group.

Naming of Ketones

  • CH3COCH3    : IUPAC name: Propanone         Common name: acetone.
  • CH3COCH2CH3  : IUPAC name: butanone  Common name: ethyl methyl ketone.


  • The carbon compounds (or organic compounds) containing carboxylic acid group (-COOH group) are called carboxylic acids.
  • They are commonly known as organic acids.

Naming of Carboxylic Acids (or Organic Acids)

  • HCOOH   : IUPAC name: Methanoic acid      Common name: formic acid.
  • CH3COOH I: UPAC name: Ethanoic acid      Common name: acetic acid.

Start your learning Journey !

Get SMS link to download the app