Introduction to Organic
Chemistry
What are organic compounds?
All organic compounds contain the element carbon.
Most organic compounds also contain hydrogen.
Organic compounds that contain
only hydrogen and carbon are
called hydrocarbons.
Most natural substances are organic compounds.
Plastics and many medicines are also organic compounds.
Not all carbon-containing compounds are organic.
For example, carbon dioxide, carbon monoxide and
carbonates are not organic compounds.
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Homologous Series
There are millions of possible organic compounds.
Chemists group related organic compounds into
families or homologous series.
A homologous series is a family of organic compounds with
the same functional group and similar chemical properties.
Examples of homologous series are the alkanes
and the alkenes
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What is a functional group?
A functional group is an atom or a group of atoms that
gives a molecule its characteristic properties.
Organic compounds in the same homologous series
have similar chemical properties because they have the
same functional group.
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Homologous Series - Alkanes
Alkanes do not have any
functional groups.
There are only C – C and C – H
bonds.
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Homologous Series - Alkenes
The functional group of alkenes is the
carbon-carbon double bond.
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What are the general characteristics
of a homologous series?
Organic compounds in the same homologous
series have the following properties in common:
a) They have the same functional group.
b) They have similar chemical properties.
c) There is a gradual change in their physical
properties.
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Naming Organic Compounds
The name of an organic compound is divided into
2 parts:
a) 1st part (prefix) tells us the number of carbon atoms
in each molecule.
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Naming Organic Compounds
The name of an organic compound is divided into 2
parts:
b) The 2nd part (suffix) of the name tells us the
homologous series of the compound.
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Naming Organic Compounds
Propene is an alkene with 3 carbon atoms
per molecule.
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