NEET General Organic Chemistry Functional Groups Notes

Functional Groups

Functional Groups Definition:

A functional group is defined as “an atom or group of atoms present in a molecule which decides the chemical properties of the organic compounds”. Double and triple bonds are also considered as functional groups.

The organic compounds are further classified into different classes depending upon the nature of functional group.

NEET organic chemistry functional groups notes

Classification of organic compounds based on functional group is summarised in the table.

Read And Learn More: NEET General Organic Chemistry Notes, Question And Answers

Homologous Series

A series of structurally related organic compounds with a same functional group can be represented by a general formula and differ by -CH₂ group is called homologous series. The individual members of such series is called homolouge and this phenomenon is known as homology.

Functional groups in organic chemistry for NEET

General organic chemistry functional groups NEET study material

Characteristics of a homologous series are as follows.

• Each homologues series can be represented by general molecular formula.
• Exp – General molecular formula of alkane is C_nH_2n+2. Molecular formula C_nH_2nO₂ represents alkanoic acids (carboxylic acids) and alkyl alkanoates (esters).
• All the members of a given homologous series (homologues) possess the same functional group.
• The successive members of a homologous series differ by a -CH₂– group or by mass units.
• Homologues of a homologous series can be prepared by general methods.
• The physical properties such as boiling point, melting point, density, etc., of the members of a homologues series show a regular gradation with increase in molecular mass.
• Chemical properties of the members of a homologous series are similar though the first homologue may vary considerably from the rest of the homologues.