Drill: Calculate the pH of 0.10 M H2Z in 0.50 M KHZ. -5 Ka1 = 2.0 x 10 -9 Ka2 = 5.0 x 10 Review Drill & Check HW CHM II HW • Review PP-24. • Complete the attached assignment & turn it in tomorrow. Salt or Hydrolysis Reactions Hydrolysis Any reaction in which water is decomposed with all or part of its decomposition portions combining with the products Hydrolysis Water is added to decompose something Hydrolysis MX + HOH HX + MOH Salts Salts •Ionic compounds that dissolve ~ 100 % in water Salts of Acids •Salts of acids are negative (A ) Salts of Bases •Salts of bases are Positive + + (M or B ) Salt Solutions •When salts dissolve, their ions can recombine with water Salt Solutions •The salts of weak acids can recombine with water producing basic solutions Salt Solutions •The salts of weak bases can recombine with water producing acidic solutions Salt Solutions A + B + H2O HA + + H 2O + H OH + BOH Drill: Calculate the salt/acid ratio of a solution of benzoic acid & sodium benzoate at a pH of 5.00. -5 Ka HBz = 6.4 x 10 Salt or Hydrolysis Problems Drill: Calculate the pH of a solution of 0.10 M NH3 in 0.20 NH4Cl. Kb NH3 = 1.8 x -5 10 Salt Problem •Calculate the pH of a 0.20 M solution of NaBz -5 •Ka HBz = 6.4 x 10 Salt Problem •Calculate the pH of a 0.10 M solution of R-NH3Cl -5 •Kb R-NH2 = 2.5 x 10 Drill: Calculate the pH of a 0.18 M solution of KC2H3O2 -5 •Ka = 1.8 x 10 Review Drill & Check HW Collect Labs CHM II HW •Study for a quiz tomorrow •Test Monday AP CHM HW •Read: Chapter 14 •Problems: 43 •Page: 422 CHM II HW •Read: Chapter 18 •Problems: 83 •Page: 790 Salt Applications •Salts of strong acids & weak bases make acidic solutions Salt Applications •Salts of strong bases & weak acids make basic solutions Salt Applications •Salts of strong acids & strong bases make neutral solutions Predict Relative pH •NaAc •KNO3 •KHSO4 MnCl2 NH4Br NH4Ac Predict Relative pH •KAc •KClO2 •K2SO4 NaCl NH4Cl NaI Anhydrides •Compounds without water; that when added to water, form other compounds Acid Anhydrides •Non-metal oxides that form acids when added to water Basic Anhydrides •Metal oxides that form bases when added to water Predict Relative pH •Na2O SO2 •NO2 CO2 •CaO Al2O3 Calculate the pH of a 0.16 M solution of KC7H5O2 -5 •Ka = 6.4 x 10 •Calculate the pH of a solution of 0.0030 M KQ. -5 •Ka HQ = 3.0 x 10 AP CHM HW •Read: Chapter 14 •Problems: 35 •Page: 422 CHM II HW •Read: Chapter 18 •Problems: 67 & 75 •Page: 789-790 Drill: Calculate the pH of a 0.72 M NH4NO3 solution. -5 Kb NH3 = 1.8 x 10 A/B eq, Buffer & Salt Hydrolysis Problems AP Test •Thursday 11.2 g of KOH was added to 2.0 L of 0.075 M H2CO3. Calculate the molarity of all ions present in the solution. -7 Ka1 = 4.4 x 10 -11 Ka2 = 4.8 x 10 You need to make a buffer solution with its greatest buffering capacity at pH ~ 5.4. In general terms, describe what acid or base you would chose, & how you would make the buffer. Calculate the pH of 0.10 M HF. -4 Ka HF = 6.5 x 10 -1], Calculate [H3PO4], [H2PO4 -2 -3 + + [HPO4 ], [PO4 ], [K ], [H ], & pH of 1.0 M KH2PO4 in 0.50 M K2HPO4. -3 Ka1 = 7.5 x 10 -8 Ka2 = 6.2 x 10 -13 Ka3 = 4.2 x 10 Calculate the pH of 0.10 M HF in 0.20 M NaF. -4 Ka HF = 6.5 x 10 Calculate the pH of 5.0 M KCN. -10 KaHCN= 5.0 x 10 Calculate pH of: 0.20 M MOH in 0.50 M MCl -5 Kb = 5.0 x 10 Calculate pH of: 0.20 M MCl -5 Kb = 5.0 x 10 Drill: Calculate the pH of 0.20 M KQ. -5 Ka HQ = 8.0 x 10 Predict Relative pH •KAc •KClO2 •K2SO4 NaCl NH4Cl NaI Predict Relative pH K2O ClO2 SO3 MgO (NH4)2O N2O3 Calculate pH of: •0.20 M HNO2 -4 •Ka = 2.0 x 10 Calculate pH of: •3.0 M HZ in 2.0 M KZ •Ka HZ = 3.0 x -5 10 Calculate pH of: •0.20 M KR -5 •Ka HR = 2.0 x 10 Calculate pH of: •2.0 M HQ -6 •Ka = 2.0 x 10 Calculate pH of: •0.60 M HZ in 0.90 M KZ •Ka HZ = 3.0 x -5 10 Calculate pH of: •0.20 M KQ -7 •Ka HQ = 2.0 x 10 1.5 L of 0.25 M Ba(OH)2 was added to 1.0 L of 0.60 M H2SO3. Calculate [H2SO3], -2 + [HSO3 ], [SO3 ], [H ], [OH ], & pH of the solution. -2 Ka1 = 1.7 x 10 -8 Ka2 = 6.0 x 10 Review of Acid/Base descriptions and Acid/Base, Buffer, & Salt Equilibria Arhenius, BronstedLowry, & Lewis Acids & Bases Strong Acids Strong Bases Acid rxns Base rxns A/B Equilibrium Constants KW, KA, KB, & pH Calculate pH of: •0.025 M HNO3 •0.020 M KOH 150 mL of 0.10 M KOH was added to 100.0 mL of 0.10 M H2CO3. Calculate [H2CO3], -2 + [HCO3 ], [CO3 ], [H ], [OH ], & pH of the solution. -7 Ka1 = 4.4 x 10 -11 Ka2 = 4.7 x 10 -1 A ], Calculate [H3A], [H2 -2 -3 + + [HA ], [A ], [K ], [H ], [OH ], & pH of 2.0 M KH2A. -3 Ka1 = 4.0 x 10 -8 Ka2 = 5.0 x 10 -13 Ka3 = 2.5 x 10