ASChemistryCIERevision Notes13. An Introduction to AS Level Organic Chemistry13.1 Formulas, Functional Groups & the Naming of Organic CompoundsFunctional Groups & their Formulae

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Functional Groups & their Formulae (CIE AS Chemistry)

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Functional Groups of Organic Compounds

  • 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

An Introduction to AS Level Organic Chemistry Functional Groups, downloadable AS & A Level Chemistry revision notes

Formulae of Organic Compounds

  • The general formula is a formula that represents a homologous series of compounds using letters and numbers
    • Eg. the general formula of alkanes is CnH2n+2
    • A homologous series is a group of organic compounds that have the same functional group, the same general formula and the same chemical properties

  • The structural formula is a formula that shows how the atoms are bonded to each carbon atom in a molecule
  • The displayed formula is a 2D representation of an organic molecule showing all its atoms (by their symbols) and their bonds (by single, double or triple bonds)
  • The skeletal formula is a simplified displayed formula with all the carbon and hydrogen (C-H) bonds removed

Overview of the formulae of organic compounds table

formulae-of-organic-compounds-1

Worked example

Draw the skeletal formula of the following molecules:

  1. CH3(CH2)3OH
  2. (CH3)2CHCH2OH
  3. CH3CH2OCH2CH3

Answer:An Introduction to AS Level Organic Chemistry Answer Worked example - Drawing skeletal formulae of molecules, downloadable AS & A Level Chemistry revision notes

Worked example

Draw the fully displayed formula of the following molecules:

3-1-an-introduction-to-as-level

Answer:

An Introduction to AS Level Organic Chemistry Answer Worked example - Drawing displayed formulae of molecules, downloadable AS & A Level Chemistry revision notes

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    Philippa

    Author: Philippa

    Expertise: Chemistry

    Philippa has worked as a GCSE and A level chemistry teacher and tutor for over thirteen years. She studied chemistry and sport science at Loughborough University graduating in 2007 having also completed her PGCE in science. Throughout her time as a teacher she was incharge of a boarding house for five years and coached many teams in a variety of sports. When not producing resources with the chemistry team, Philippa enjoys being active outside with her young family and is a very keen gardener.