What are homologous series

What are homologous series

In organic Chemistry, the role and importance of Homologous series can’t be over emphasized, as it plays a major role in identifying organic compounds.Homologous series is a series, family or group of organic compounds that have similar structures and similar chemical properties but it successive member differ by a -CH2 group.



In naming organic compound, you must be very careful and understand the role homologous series plays, after you might have determine or identified  which functional group is present

 

CHARACTERISTICS OF HOMOLOGOUS SERIES


1.   All members of the homologous series can be identified by a general formula. The general formula of Alkane is CnH2n+2  alkenes  CnH2n  and alkynes CnH2n-2
2.  All members have a general method of preparation for example, Methane can be prepared by the action of heat on a mixture of soda lime and appropriate sodium salt of alkanoate
3. They have similar chemical properties, for example, members belonging to the alkane family or series undergoes combustion reaction and substitution reaction. Alkene undergoes combustion reaction, addition reaction and polymerization reaction.
4.  Each member of the homologous series differ from the preceding of succeeding member  by  a –CH2 group  and has a relative formula mass of 14
5.  The physical properties of member changes gradually in the same direction as the number of carbon atoms increases or decrease.