1. Liquids and Solids
Zumdahl, Ch. 10

2. Try to remember - KMT Volume of the particle is negligible
Particles are in constant random motion
Particles exert no forces between each other

3. Intermolecular Forces (IMF)
Also known as Van der Waals forces
Dipole-Dipole Force
Hydrogen Bonding
London Dispersion

4. Intramolecular Forces
Also known as bonds
Ionic bond: kJ/mol
Covalent bond: 150 – 1000 kJ/mol
Intermolecular forces significantly less
Importance of Intermolecular Forces (IMF)
Freezing point and boiling point
Vapor pressure

5. Dipole – Dipole Force Polar molecules attract each other
5 – 25 kJ/mol (decrease with distance)

7. Hydrogen “Bonding” Special case of dipole-dipole: 10-40 kJ/mol
H atom and N, O, F, (Cl)
Role in DNA structure
THE example: H2O

9. London Dispersion Force
Any molecule with positive nuclei and negative electrons has LDF.
So, EVERYTHING HAS LDF!
0.05 – 40 kJ/mol Why such a huge range?
As molar mass increases, LDF increases

10. LDF = Atomic-Sized Dipole

11. Summary of IMFs London Dispersion Dipole-Dipole Force Hydrogen Bonding
Typically weakest IMF
Dominates for large molecules
Dipole-Dipole Force
Found in polar molecules
Dominates as EN differences increase
Hydrogen Bonding
H and N, O, F, (Cl)
Typically the strongest IMF

12. IMFs Impact on Liquids As IMF increases, boiling point increases
As IMF increases, vapor pressure decreases
As IMF increases, surface tension increases
As IMF increase, viscosity increases
Capillary action