Homologous series
In Organic Chemistry , Homologous series is defined as a series of compounds with identical functional groups.
Any two successive member of such a series differs by CH
2 in molecular formula and by 14 unit of mass in molecular weight.
Members of such a series have same general formula.
Such organic compounds that vary from one another by a repeating unit and have the same general formula form a series of compounds.
Examples:
Example1 :
Pentane.
and
Heptane Both have same general formula C
nH
2n+2 as well as fuctional group (alkane.)
Example2 :
2-Butene
and
2-Pentene
Both have same general formula C
nH
2n as well as fuctional group (alkene.)
Example3 :
Cyclobutene
and
Cyclohexene
Both have same general formula C
nH
2n-2 as well as fuctional group (Cycloalkene.)
Example4 :
Ethanol
and
2-Propanol
Both have same general formula C
nH
2n+2O as well as fuctional group (Alcohol).
Example5 :
Ethanoic Acid
and
Propanoic Acid
Both have same general formula C
nH
2nO
2 as well as fuctional group (Carboxylic Acid)