Homologous series

• A homologous series is a group of organic compounds that have the same functional group, but each successive member differs by CH2

Ethanol and propanol belong to the same homologous series

Homologous Series of Alkanes

• Things we can say about a?homologous series:
  • Each member has the same?functional group
  • Each member has the same?general formula
  • Each member has?similar?chemical properties
  • Each successive member differs by? -CH2?–
  • Members have gradually changing physical properties, for example, boiling point, melting point and density
• As a homologous series is ascended, the size of the molecule increases
• This has an effect on the physical properties, such as boiling point and density

Functional Groups

• Functional groups determine the physical and chemical properties of molecules
• The table below shows a summary of common functional groups found in compounds
• R is any other atom or group of atoms (except for hydrogen)

Functional Groups found in Compounds Table