1. X-Ray Diffraction: Determining the distance between planes of atoms X-rays and atoms Orders of diffraction Bragg’s Law

2. Using X-Ray Diffraction: Bragg’s Law Platinum metal crystallizes in a face-centered cubic lattice with one atom per lattice point. Monochromatic X-radiation from a Mo target has a wavelength of 71.07 pm. If this radiation is used in a diffraction experiment with a platinum crystal, a second order diffracted beam is observed at a theta value of 10.43°. If the spacing between these planes corresponds to the unit cell length (d = a), what is the d-spacing between the planes that gave rise to this reflection?

3. Chapter 13: Mixtures: solutions, complex mixtures, colligative properties

4. Chapter 13: Colligative Properties : Properties of the solvent that change upon dissolution Vapor pressure Boiling point Freezing point Osmotic pressure ***Key #1: This all involves solute particles “blocking” molecules from leaving the liquid state: ***Key# 2: It does not matter what the solute is, just how many particles (molecules or ions are present)

5. Concentration Units Molarity Molality Mole Fraction Weight Percent ppm ppb

7. Colligative Propreties : Properties of the solvent that change upon dissolution Vapor Pressure of water at 20 o C is 20.1 mm Hg. What is the pressure of 100 g water mixed with 100 g ethylene glycol, C 2 H 4 (OH) 2 ?

8. Distillation: Changing the composition of a mixture of volatile liquids Vapor Pressures at 50 o C Water99 mm Hg Ethanol232 mmHg Distill a 10% alcohol solution.

9. Freezing and Boiling Point Changes & Phase Diagrams

10. Boiling Point Elevation: An extension of Vapor Pressure Lowering

11. Boiling Point Elevation

12. Freezing Point Depression

13. Effect of Ions:  T fp = K fp mi i = van’t Hoff factor Van’t Hoff factors: NH 3 KCl CaCl 2 FeBr 3

15. Which is better at melting ice, per gram, NaCl or CaCl 2 ?