Summary Notes 3.3.1 - Introduction to organic chemistry

Taylor’s Notes Introduction to Organic

Homologous Series
 Consecutive members differ by CH2
 Similar chemical properties
 Trends in physical properties
 Same functional group

The functional group is the part of the molecule which determines which homologous series it is part of

Nomenclature
The first part of the name is given based on the number of carbon atoms in the molecule

Number of C atoms Name Number of C atoms Name Number of C atoms Name
1 Meth- 4 But- 7 Hept-
2 Eth- 5 Pent- 8 Oct-
3 Prop- 6 Hex- 9 Non-

The second part of the name is given according to which homologous series they belong

Functional Name of Suffix/Prefix Functional Name of Suffix/Prefix
Group Functional Group Group Functional Group

Alkene -ene Alcohol -ol


chloro- Aldehyde -al


Halogenoalkane bromo- Ketone -one


Iodo- Carboxylic Acid -oic acid


If a molecule contains an OH group it will end with the name -ol However, if it contains another group,
such as a carboxylic acid, the alcohol is named as hydroy- in front on the name, and the -oic acid at the end

Types of Formulae
Empirical and Molecular
Empirical formula is the lowest whole number ratio of atoms

Molecular formula is the actual ratio of atoms

IUPAC Name Molecular Formula Empirical Formula
Methane CH4 CH4
Propene C3 H 6 CH2
Butane C4H10 C2H5