Analía Bellizzi – Chemistry Classes

Ronald Reagan Senior High School

HOMOLOGOUS SERIES

Describe the concept of homologous series as…
● A ‘family’ of similar compounds with similar chemical properties due to the
presence of the same functional group

(Extended only) Describe the general characteristics of a homologous series
● Similar chemical properties – undergo the same chemical reactions
o E.g. alkenes decolourise bromine water (orange to colourless) due to the
C=C, whereas alkanes do not due to the lack of C=C
(Extended only) Recall that the compounds in a homologous series have…
● The same general formula
o General formulae = a type of empirical formula that represents the
composition of any member of an entire class of compounds (e.g. for
ALCOHOLS = CnH(2n+1)OH
(Extended only) Describe and identify structural isomerism
● Structural isomerism = compounds with the same molecular formula exist in
different forms due to different arrangements of atoms
● Can be positional isomers due to different placement of functional groups:

positional-1

Can be functional isomers due to different functional groups but with the exact same group of atoms:

Can be structural isomers due to branched or unbranched chains