660 likes | 874 Views
Drill: Calculate the pH of 0.10 M H 2 Z in 0.50 M KHZ. K a1 = 2.0 x 10 -5 K a2 = 5.0 x 10 -9. 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.
E N D
Drill: Calculate the pH of 0.10 M H2Z in 0.50 M KHZ.Ka1 = 2.0 x 10-5 Ka2 = 5.0 x 10-9
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 • 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- + H2O HA + OH- • B+ + H2O H+ + BOH
Drill: Calculate the salt/acid ratio of a solution of benzoic acid & sodium benzoate at a pH of 5.00.KaHBz = 6.4 x 10-5
Salt Problem • Calculate the pH of a 0.20 M solution of NaBz • Ka HBz = 6.4 x 10-5
Drill: Calculate the pH of a solution of 0.10 M NH3 in 0.20 NH4Cl.Kb NH3 = 1.8 x 10-5
Salt Problem • Calculate the pH of a 0.20 M solution of KNO2 • Ka HNO2 = 7.1 x 10-4
Salt Problem • Calculate the pH of a 0.10 M solution of R-NH3Cl • Kb R-NH2 = 2.5 x 10-5
Calculate the pH of a 0.18 M solution of KC2H3O2 • Ka = 1.8 x 10-5
Drill: Calculate the salt to acid ratio required to make a buffer solution with a pH of 4.495 using benzoic acid.KaHBz = 6.4 x 10-5
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 MnCl2 • KNO3 NH4Br • KHSO4 NH4Ac
Predict Relative pH • KAc NaCl • KClO2 NH4Cl • K2SO4 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 • Ka = 6.4 x 10-5
Calculate the pH of a solution of 0.0030 M KQ. • KaHQ = 3.0 x 10-5
Drill: Calculate the pH of a 0.72 M NH4NO3 solution.KbNH3 = 1.8 x 10-5
Calculate [H3PO4], [H2PO4-1], [HPO4-2], [PO4-3], [K+], [H+], & pH of 1.0 M KH2PO4 in 0.50 M K2HPO4. Ka1 = 7.5 x 10-3Ka2 = 6.2 x 10-8Ka3 = 4.2 x 10-13
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.
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.Ka1 = 4.4 x 10-7Ka2 = 4.8 x 10-11
Drill: Calculate the pH of 0.10 M HF. Ka HF = 6.5 x 10-4
Calculate the pH of 0.10 M HF in 0.20 M KF. Ka HF = 6.5 x 10-4
Predict Relative pH K2O MgO ClO2 (NH4)2O SO3 N2O3
Predict Relative pH • KAc NaCl • KClO2 NH4Cl • K2SO4 NaI
Calculate pH of: 0.20 M MOHin 0.50 M MCl Kb = 5.0 x 10-5
Calculate pH of: 0.20 M MCl Kb = 5.0 x 10-5