1. Announcements To join clicker to class today: – Turn on the Clicker (the red LED comes on). – Push “Join” button followed by “20” followed by the “Send” button (switches to flashing green LED if successful). ● Exam 4 scores available on D2L. ● Bring possible errors to Dr. Gutow's attention as soon as possible. ● Wear appropriate clothes to Lab!

2. Chapter 9 - Intermolecular Forces A. Ion-Ion interactions (Coulomb’s law, Lattice Energy) B. Dipole interactions (ion-dipole, dipole-dipole, dipole- induced dipole,induced dipole-induced dipole, Hydrogen bonding) C. Solubility(miscible & immiscible) D. Vapor Pressure (Raoult’s law E. Phase diagrams F. How this explains water’s unusual properties (surface tension, meniscus, capillary action, viscosity, structure of ice).

3. Ion-Ion interactions Coulomb’s Law (2 charged particles): E = 2.31 x 10 -19 Jnm(Q 1 Q 2 /d) Q i is charge on particle in coulomb d is distance between center of charges in nm Q1Q1 Q2Q2 d

4. Crystal Lattice

5. Lattice Energy Coulomb’s Law (2 charged particles): E = 2.31 x 10 -19 Jnm(Q 1 Q 2 /d) Lattice Energy U (crystal lattice of charged particles): U=k(Q 1 Q 2 /d) –U is energy per mole of formula units (e.g. mole of NaCl or CaCl 2, etc) –k = a constant that accounts for geometry and the factor of N A Definition: U = the energy given up when enough gaseous ions combine to form one mole of the solid.

6. Fig. 9.4 2