Intro to organic chem

• Define empirical formula

  simplest whole number ratio of atoms of each element in a compund
• Molecular formula


  actual numbers of each element in a compound
• structural formula shows

  how the atoms in a molecule are arranged, CH3CH2CH2CH3
• Displayed formula shows

  all the atoms and bonds in a molecule
• skeletal formula shows

  the shape of the carbon skeleton
• homologous series

  compounds containing the same functional group and having the same general formula but having different carbon chain length. Each successive member has an extra CH2. They are also chemically similar
• functional group


  an atom or group of atoms which gives an organic compound its particular chemical properties
• hydrocarbon

  compounds containing carbon and hydrogen atoms only
• saturated hydrocarbons

  contains single carbon bonds only
• unsaturated hydrocarbons

  contains one or more carbon-carbon double bonds
• aliphatic hydrocarbons


  has a chain of C atoms
• alicyclic 


  has a ring of C atoms
• aromatic

  contains a benzene ring, C6H6
• Nomenclature

  1. the stem: tells us how many carbons there are in the longest chain bearing the functional group
  2. the prefix: added before the stem, tells us the position of the side chains, R, often an alkyl group
  3. the suffix: added after stem, tells us the functional group, e.g. alkanes ANE
• 1


  meth
• 2


  eth
• 3

  prop
• 4

  but
• 5

  pent
• 6


  hex
• 7

  hept
• 8

  oct
• 9

  non
• 10

  dec
• methyl- 1c, ethyl- 2c, propyl- 3c
• aliphatic alkanes general formula

  CnH2n+2
• How to name branched alkanes

  1. find the longest chain and name stem
  2. identify the alkyl groups as side chains, added as a prefix
  3. give the position of the side chain by numbering the main chain starting from the end which gives lowest number
  4. name alkyl groups in alphabetical order (if more than 1), number main chain from end which gives lowest combo. if alkyl groups are same: di-, tri-, tetra-, each alkyl group is given its own number, numbers are separated from names by hyphens, and numbers are separated from other numbers by comma
• naming cyclic alkanes

  CnH2n

  stem is cyclo
• structural isomers


  compounds with same molecular formula but a different structural formula
• chain isomers


  the hydrocarbon chain is arranged differently
• position isomers

  same functional group in a different position, e.g propan-1-ol, propan-2-ol
• functional group isomers


  different functional group, e.g ketones and aldehydes, cyclic alkanes and alkenes
• stereoisomers

  compounds with the same structural formula but a different arrangement of atoms in space

  e/z or optical