The Basics

• The general forumula is an algebraic formula that can describe any member of a family of compounds.
• The empirical formula is the simplist ratio of atoms of each element in a copound (cancel the numbers down where possible).
• The moleclar formula is the acual number of atoms of each element in a molecule.
• The structural formula shows the atoms carbon by carbon, with the attached hydrogens and functional groups.
• The skeletal formula shows the bonds of the carbon skeleton only, with any functional goups. The hyrdogen and carbon atoms aren't shown.
• The displayed formula shows how all the atoms are arranged, and all the bonds between them.
• Homologous compounds have the same general formula. They contain the same functional group.

  You can use a general formula to work out the molecular forumla of any member of a homologous series.

  Each successive member of a homologous series differs by a CH2 group.
• Homologous series: Alkanes

  Prefix/Suffix: -ane

  Example: propane [CH3CH2CH3]
• Homologous series: Branched alkanes

  Prefix/Suffix: alkyl-

  Example: methylpropane [CH3CH(CH3)CH3]
• Homologous series: Alkenes

  Prefix/Suffix: -ene

  Example: propene [CH3CH=CH2]
• Homologous series: Halogenoalkanes

  Prefix/Suffix: fluoro- / chloro- / bromo- / iodo-

  Example: chloroethane [CH3CH2Cl]
• Homologous series: Alcohols

  Prefix/Suffix: -ol

  Example: ethanol [CH3CH2OH]
• Homologous series: Aldehydes

  Prefix/Suffix: -al

  Example: ethanal [CH3CHO]
• Homologous series: Ketones

  Prefix/Suffix: -one

  Example: propanone [CH3COCH3]
• Homologous series: Carboxylic acid

  Prefix/Suffix: -oic acid

  Example: ethanoic acid [CH3COOH]
• Homologous series: Esters

  Prefix/Suffix: alkyl- -otae

  Example: ethyl ethanoate [CH3COOCH2CH3]
• Homologous series: Amines

  Prefix/Suffix: -amine

  Example: methylamine [CH3NH2]
• Homologous series: Amides

  Prefix/Suffix: -amide

  Example: ethanamide [CH3CONH2]
• Homologous series: Acyl chlorides

  Prefix/Suffix: -oyl chloride

  Example: ethanoyl chloride [CH3COCl]
• Homologous series: Cycloalkanes

  Prefix/Suffix: cyclo- -ane

  Example: cyclohexane [C6H12]
• Homologous series: Arenes

  Prefix/Suffix: -benzene (or phenyl-)

  Example: methylbenzene [C6H5CH3]
• Nomenclature is the naming of organic compounds.

  Rules:

  • Count the longes continuous chain that contains the functional group (this gives you the stem).
  • The main funcional group gives you the end of the name (suffix).
  • The number of carbons in the longest carbon chain (so that the carbon with the main functional group has the lowest possible number).
  • Any side-chains or less important functional groups are added as prefixes.
  • If there is more than one identical side chain / funtional group use di- / tri- etc.
• Carbon number = stem:

  • 1 = meth-
  • 2 = eth-
  • 3 = prop-
  • 4 = but-
  • 5 = pent
  • 6 = hex-
• A mechanism breaks down a reaction into individual stages.

  They show how molecules react together by using curly arrows to show which bonds are made / broken. They show how electron pairs move around.