Edexcel A Level Chemistry:复习笔记3.1.2 Homologous Series & Functional Groups

Homologous Series & Functional Groups


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