Intermolecular Bonds

Types of Bonds
- Intramolecular bonds
   - exist within a molecule
   - ionic, covalent
- Intermolecular bonds exist between molecules
   - The stronger the intermolecular bonds the higher the boiling point or melting point
   - Two types of Intermolecular : Van der Waals Bonds and Hydrogen bonds

Van der Waals Bonds
- Based on electron distribution
- Two categories
1) Dipole - Dipole bonds
    - If a molecule is polar the positive end of one molecule will be attracted to the negative end of another      molecule
2) London Dispersion Forces (LDF)
    - LDF is present in all molecules
    - creates weakest bonds
    - if a substance is non-polar dipole-dipole forces don't exist
    - Electrons are free to move around and will randomly be grouped on one side of the molecule
    - This creates a temporary dipole and can cause a weak bond to form
    - The more electrons in the molecule the stronger the LDF can be

Hydrogen Bonding
- If Hydrogen is bonded to certain elements (F, O, or N) the bond is highly polar
- This forms a very strong intermolecular bond

Effects of Bonds
- Melting and boiling points are a measure of intermolecular bond strength

- JanCarlo Paysan