To Do Finish reading Chapter 4. Text homework for Chapter 4. Quiz #2 on Friday, February 12 Lon-Capa assignment #3. 1

Exam Tuesday, 2/16, 7:00-8:30 pm; rooms online. Conflict exam; 2/16, 5:00-6:30 pm; in 153 Mechanical Eng. Bldg. Sign up in 367 Noyes Lab Review sessions To be announced 2

Dissolving of an Ionic Compound 3

NaCl Dissolves 4

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Solubility Rules 7

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Precipitation Reactions  Know how to use the solubility rules (you will be given them on the exam).  Know how to write equations from reactants (ionic reactants).  Understand what solutions “look” like at a very magnified level.  Be able to do stoichiometry calculations. 9

Clicker Question When lead(II) nitrate and potassium iodide are mixed, which are the possible products? 1.PbI 2.PbI 2 3.K(NO 3 ) 2 4.KNO 3 a) 1 & 3b) 1 & 4c) 2 & 4d) 2 & 3 10

Solubility Rules Given: Pb(NO 3 ) 2 (aq) + 2KI(aq) → PbI 2 + 2KNO 3 PbI 2 must be the solid. Solubility Rules Most nitrate salts are soluble. Most salts of sodium, potassium, and ammonium cations are soluble.  Most chloride salts are soluble. Exceptions: Ag + and Pb 2+.  Most sulfate salts are soluble. Exceptions: Ca 2+, Ba 2+, and Pb 2+.  Most hydroxide salts are only slightly soluble. Soluble ones are: Na +, K +, and Ca 2+.  Most sulfide, carbonate, and phosphate salts are only slightly soluble. 11

Clicker Question Which solution is the most concentrated? (note: this is #90 from Chapter 4) 12

Practice Problems  You dissolve 10.0 g of NaCl in mL of solution. Determine the concentration in molarity.  Describe how to make mL of 0.100M NaOH from a stock solution of 8.00M NaOH. 13