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). No quiz today, just worksheet. Note that we are skipping parts of Chapter 5. See the reading assignment. Scores recorded for you (except for lab) are posted in D2L. Reminder: Grading scale in chemistry is different from high school.

2. Review How we quantify what is dissolved in solution –Mass solute/mass sol’n (mg/kg = ppm, etc) –Molarity (M) = mol solute/L sol’n Calculating amount of solution necessary to get a particular amount of solute. Converting between mass/mass and molarity units. – 1) convert mass solute––> moles solute – 2) use density to convert mass sol'n to L sol'n.

3. Concentration Unit Conversions What is the ppb of Cl - in a 0.050 M CaCl 2 solution? – Solution density = 0.995 g/mL – MM(Ca + ) = 40.08 g/mol – MM(Cl - ) = 35.45 g/mol

4. Effect of Osmosis on Blood Cells Mathematics of Osmosis: Π =MRT, M = molarity of solute particles, R = gas constant = 0.08206 Latmmol -1 K -1, T = temperature in K.