IB CHEMISTRY:
TOPIC 10 ORGANIC CHEMISTRY NOTES
10.1 Fundamentals of organic chemistry
Homologous series
• Homologous series: A series of compounds of the same family, with the same general
formula, which differ from each other by a common structural
# C atoms Prefix
unit
• The main features of a homologous series are: 1 meth-
o Members of a homologous series show a gradation in
their physical properties due to the gradual increase of 2 eth-
sizes and weight (example: boiling points increase)
3 prop-
o Members of a homologous series show similar
chemical properties as all compounds in the series 4 but-
have the same functional group (functional groups are
5 pent-
the reactive part)
o Successive members of a homologous series differ by
6 hex-
a –CH2— group
• Members of a homologous series are represented by same formula. They are named by:
o Prefix: # Of carbon atoms in the longest chain
Homologous Description Formula Suffix
Series
Alkanes Saturated hydrocarbons containing carbon-carbon single bonds 𝐶! 𝐻"!#" -ane
Alkenes Unsaturated hydrocarbons containing carbon-carbon double bonds 𝐶! 𝐻"! -ene
Alkynes Unsaturated hydrocarbons containing carbon-carbon triple bonds 𝐶! 𝐻"!$" -yne
o Suffix: Homologous series to which the compound belongs
, Organic compound classes
• Each class name contains a specific functional group which is a chemical group (small
molecule) that determines the specific chemical properties of a compound, which in turn
determines the type of chemical reactions it undergoes
• This means that different compounds/classes in organic chemistry undergo characteristic
reactions depending on the functional groups they contain
o Functional groups are specific groups of atoms or bonds within molecules that
are responsible for the characteristic chemical reaction of those molecules
o A functional group is either named as a prefix or a suffix
• Example classes and functional groups include:
Class:
Alkane Alkenes Alkynes
Functional Group: −𝐶 − 𝐶 − −𝐶 = 𝐶 − −𝐶 ≡ 𝐶 −
Suffix - ane - ene - yne
Class: Alcohols Aldehyde
Functional Group: −𝑂𝐻
Name/Suffix Hydroxyl - ol Aldehyde - al
Class: Amine Amide
Functional Group:
Name Amines Carboxyamide
Class: Ether Ester Nitrile
Functional Group: 𝐶−𝑂−𝐶 −𝐶 ≡ 𝑁
Name Ether Ester Nitrile
Class Ketones Carboxylic Acid Arenes
TOPIC 10 ORGANIC CHEMISTRY NOTES
10.1 Fundamentals of organic chemistry
Homologous series
• Homologous series: A series of compounds of the same family, with the same general
formula, which differ from each other by a common structural
# C atoms Prefix
unit
• The main features of a homologous series are: 1 meth-
o Members of a homologous series show a gradation in
their physical properties due to the gradual increase of 2 eth-
sizes and weight (example: boiling points increase)
3 prop-
o Members of a homologous series show similar
chemical properties as all compounds in the series 4 but-
have the same functional group (functional groups are
5 pent-
the reactive part)
o Successive members of a homologous series differ by
6 hex-
a –CH2— group
• Members of a homologous series are represented by same formula. They are named by:
o Prefix: # Of carbon atoms in the longest chain
Homologous Description Formula Suffix
Series
Alkanes Saturated hydrocarbons containing carbon-carbon single bonds 𝐶! 𝐻"!#" -ane
Alkenes Unsaturated hydrocarbons containing carbon-carbon double bonds 𝐶! 𝐻"! -ene
Alkynes Unsaturated hydrocarbons containing carbon-carbon triple bonds 𝐶! 𝐻"!$" -yne
o Suffix: Homologous series to which the compound belongs
, Organic compound classes
• Each class name contains a specific functional group which is a chemical group (small
molecule) that determines the specific chemical properties of a compound, which in turn
determines the type of chemical reactions it undergoes
• This means that different compounds/classes in organic chemistry undergo characteristic
reactions depending on the functional groups they contain
o Functional groups are specific groups of atoms or bonds within molecules that
are responsible for the characteristic chemical reaction of those molecules
o A functional group is either named as a prefix or a suffix
• Example classes and functional groups include:
Class:
Alkane Alkenes Alkynes
Functional Group: −𝐶 − 𝐶 − −𝐶 = 𝐶 − −𝐶 ≡ 𝐶 −
Suffix - ane - ene - yne
Class: Alcohols Aldehyde
Functional Group: −𝑂𝐻
Name/Suffix Hydroxyl - ol Aldehyde - al
Class: Amine Amide
Functional Group:
Name Amines Carboxyamide
Class: Ether Ester Nitrile
Functional Group: 𝐶−𝑂−𝐶 −𝐶 ≡ 𝑁
Name Ether Ester Nitrile
Class Ketones Carboxylic Acid Arenes
