1. WARM UP 1.How do you determine if a bond is ionic, polar covalent, or nonpolar? 2.How do you determine if an entire molecule is polar or nonpolar? 3.Draw a water molecule, indicating the + and – ends.

2. Intermolecular Forces

3. Video Demonstration

4. IMF Overview Force of attraction between + and – in separate molecules –Weaker than actual bonds Coulomb’s Law –Larger charge or polarity, larger intermolecular force Charles Coulomb

5. IMF Overview Polarizability –Ability of a nonpolar atom or molecule to become polar Temporary and weak charge Induced by an outside charge –More e - = higher polarizability = more charge

6. IMF Overview Studied by –Johannes van der Waals Covalent forces (gases) –Fritz London Dispersion forces

7. Ion-Ion Ions in crystals –NaCl

8. Dipole-Dipole Opposite ends of polar molecules

9. Hydrogen Bonds Very strong dipole-dipole –H bonded to O, N, or F Adjacent H and O/N/F attract

10. Ion-Dipole Ion and polar molecule –Salt water

11. Ion – Induced Dipole Ion and nonpolar

12. Dipole – Induced Dipole Polar and nonpolar –O 2 in water

13. Dispersion / London (a.k.a. induced dipole – induced dipole) Two nonpolars –CO 2 Random e- movement creates temporary dipoles

14. WRAP UP Explain the term polarizability, using an example.

15. WARM UP List 5 different intermolecular forces, and write a 3-word description of each.

16. WRAP UP 1.Identify the intermolecular forces present in each of the following mixtures: -NH 3 and NH 3 -CaF 2 and H 2 O -NaCl and H 2 -O 2 and N 2