1.7 L2 Functional groups and the
naming of organic compounds
Outcomes - To be able to:
• identify the functional groups present in an organic molecule.
• apply the IUPAC nomenclature to organic compounds and be able
to draw their structures.
Connector
Explain the difference between “hazard” and “risk”.
Suggest ways that risk can be reduced so hat
reactions can be carried out safely
Crowe2008
Functional groups & homologous series
Functional groups - a single atom or group of atoms that
are largely responsible for determining the chemical
properties of organic compounds.
Homologous series –
• A family of organic compounds containing the same
functional group.
• They can be represented by a general formula, and each
member of the series differs from the next by a single
CH2 group.
• The members of a particular homologous series show
similar chemical properties, but gradually changing
physical properties.
Resource sheet 1/ Class sheet 1
Naming organic compounds
1. Identify the functional group(s) present – this gives
you the type of compound
2. Find the longest carbon chain – this gives you the
parent compound
Meth = 1
But = 4
Eth = 2
pent = 5
Prop =3
hex = 6
etc.
3. Name, with numbered position, the groups attached to
the longest carbon chain – always do this so that the
lowest numbers are used.
Note:
A methyl group is CH3A propyl group is CH3CH2CH2-
An ethyl group is CH3CH2etc.
Examples
2-methylpentane
2,2-dimethylbutane
2,3-dimethylbutane
3-ethyl-2-methylhexane.
Examples 2
propene.
cyclohexane
CH3-CH=CH-CH3
but-1-ene
but-2-ene
3-methylhex-2-ene
Examples 3
1,1,1-trichloroethane.
2-bromo-2-methylpropane.
1-iodo-3-methylpent-2-ene.
Examples 4
2-methylpropan-1-ol.
ethane-1,2-diol.
Class sheet 2
Worksheets 1 & 2