1. Intermolecular Forces (Ch6)
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2. Intramolecular vs. Intermolecular
Hold atoms together within a molecule (chem. Bonding: ionic and covalent)
Intermolecular
Attractive forces between molecules
Responsible for many properties of matter (ex. MP and BP)

3. 3 Types of Intermolecular Forces
1. Van der Waals Forces – increase with increasing mass
Dipole-Dipole Forces (attraction)
Attractive forces between polar molecules
The larger the dipole, the greater the force of attraction

4. London Disperson Forces (dipole-induced dipole force)
Strength depends of polarizability, which increases as molecular mass increases (can be stronger than dipole-dipole)
Strength of LDF increases as number of electrons increases; this is proportional to the mass; therefore, as mass increases, so does LDF

5. 3 Types of Intermolecular Forces
2. Ion-Dipole Forces
Attraction between an ion and a polar molecule
As charge increases the ability to attract polar molecules increases

6. 3 Types of Intermolecular Forces
3. Hydrogen Bonding
Limited to compounds containing H bonded to N, O, or F
Bond occurs between the H of one molecule and the N, O or F of another molecule
Strongest intermolecular force (compare boiling pt of water to other similar compounds)
Is a very strong dipole-dipole force

7. Why is an H bond so unusually strong?
The great polarity of the bond
The close approach of dipoles allowed by the small size of the hydrogen atom

8. Network Solid/Covalent Solid