<p> SI Chem 178 Ch 16, 17 Leader: Emily February 26, 2013</p><p>Review of Ch 16 16.75 Ephedrine (nasal sprays) is a weak organic base: (why!?) C10H15ON(aq) + H2O(l)  C10H15OH+(aq) + OH-(aq) A 0.035M solution has a pH of 11.33. What are the equilibrium concentrations of each of the species in solution? What is it’s Kb? What is it’s pOH?</p><p>16.86 An unknown salt is either: KBr, NH4Cl, KCN, or K2CO3. A 0.1M solution of this mysterious salt is neutral. Which salt is dissolved? </p><p>Review Acid Strength Patterns… ______New Stuff (Ch 17)</p><p>Use arrows (up/down) to compare the following concepts:</p><p>______Ionization of weak electrolyte ______Concentration of strong electrolyte with common ion</p><p>17.14 Given B(aq) + H2O(l)  HB+(aq) + OH-(aq) and using Le Chatelier’s principle, explain what the presence of a salt of HB+ does to the ionization of B. What is a salt that can decrease the ionization of NH3 in solution? What is the pH of a 1L solution containing 0.3 moles of acetic acid and 0.3 moles of sodium acetate? How do we approach this…. 1. What is the common ion?</p><p>2. Which species is a strong electrolyte, and which is weak? What will be floating around in solution? </p><p>3. Which species will actually affect pH? </p><p>4. Make your ICE table here… What must you be careful of in your “I” column? Can we likely make our 5% assumption here? What are our molarities?</p><p>5. What is your Ka equation? Write it conceptually and numerically. (The Ka of acetic acid is 1.8*10^-5)</p><p>6. What is your pH?</p><p>7. Compare: What would the pH of a simple 0.3M acetic acid solution be? (Without the sodium acetate? (And therefore, what does this tell us? Whose principles apply here?)</p><p>17.18 a) What is the % ionization of 0.125M lactic acid? (Ka= 1.5*10^-5) b) What is the % ionization of 0.125M lactic acid with 0.0075M Sodium lactate added?</p>