1. 1.7 Intermolecular Forces

2. H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl
Pour liquid between 2 beakers along with this slide.
Is this evaporating?
What does evaporating look like, in terms of these molecules?
Is this evaporating very fast?
Why? H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl

3. H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cld+ d- H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl

4. d+ d- H Cl H Cl H H Cl Cl H Cl H Cl H Cl H H Cl

5. d+ d- H Cl

6. d+ d- H Cl

7. Intermolecular Forces
Attraction forces between molecules

8. Intramolecular Force Intermolecular Force
Ionic bond
Covalent bond
Polar covalent bond
Hold together ATOMS
Breaking = chemical reaction
Dipole-dipole
London forces
Hydrogen bond
Hold together MOLECULES
Breaking = phase change, dissolving

9. Practice: Which of the following molecules are polar?
CH4
H2O
NH3 

10. C. Hydrogen Bonds
molecule contains an H atom bonded to a very electronegative atom (_____, _____, ____)
the H atom of one molecule is attracted to the F, O, or N on another molecule F O N

11. C. Hydrogen Bonds
molecule contains an H atom bonded to a very electronegative atom (_____, _____, ____)
the H atom of one molecule is attracted to the F, O, or N on another molecule
the strongest of the intermolecular forces
H has no e- to get in the way of its attraction to F, O, or N F O N

12. H – F
H – F
What would be something that would get in the way of intermolecular forces?

13. H – F
H – F

14. Example: Which of the following molecules can hydrogen bond?
HCN H2O H2S HF

15. Arrange water molecules to reflect the structure of ice.

19. Example: Which would you expect to have a higher melting point, CCl4 or CHCl3?