Module 2

• Lewis-Dot Formula

  • Electron-dot representation for organic molecules.
• Lewia Dot Formula

  1. Determine the number of valence electrons for each atom.
  2. From the chemical formula, determine how the atoms connect to each other. Identify the Central Atom: The least electronegative atom is usually the central atom.
  3. Count the number of electrons
  4. Arrange the electrons around the atoms.
• Shared pairs of electron – bonding pairs.

  Unshared pairs of electron – nonbonding pairs/ lone pairs.
• Line Bond (Kekulé) Formula

  • Bonding electrons in covalent bonds are drawn as lines and lone pair electrons are left out. Each of the atoms (C and H) is still shown in the structure.
• Condensed Formula

  • A condensed structural formula is a system of writing organic structures in a single line of text.
• Condensed Formula

  • Covalent bonds and lone pairs are omitted.
  • Atoms bonded to C (or N or O) are listed next to it with a subscript to indicate the number of atoms
• Condensed Formula

  • Parentheses can be used to show that polyatomic groups within a formula are attached to the nearest non-hydrogen atom on the left.
  • We can also use parentheses to show that polyatomic groups at the beginning of a formula are attached to the atom on the right.
• Line Angle (Skeletal) Formula

  • A shorthand representation of a molecule's bonding using lines and chemical symbol of atoms other than C and H.
• Solid Wedge and Dash Structure

  • Solid wedge - comes forwards of the plane of the page; infront
  • dashed line - goes backward out of the plane of the page; behind