Ch.16 - Aqueous Equilibria: Acids & Bases
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Problem 88b
Look up the values of Ka in Appendix C for C6H5OH, HNO3, CH3CO2H, and HOCl, and arrange these acids in order of: (b) Decreasing percent dissociation.
- The equivalence point was reached in titrations of three unknown bases at pH 5.53 (base A), 4.11 (base B), and 6.00 (base C). (a) Which is the strongest base? (b) Which is the weakest base?
Problem 92
- A vitamin C tablet containing 250 mg of ascorbic acid 1C6H8O6; Ka = 8.0 * 10-52 is dissolved in a 250 mL glass of water. What is the pH of the solution?
Problem 94
- Acetic acid 1CH3COOH; Ka = 1.8 * 10-52 has a concentration in vinegar of 3.50% by mass. What is the pH of vinegar? (The density of vinegar is 1.02 g/mL.)
Problem 95
- A typical aspirin tablet contains 324 mg of aspirin (acetylsalicylic acid, C9H8O4), a monoprotic acid having Ka = 3.0 * 10-4. If you dissolve two aspirin tablets in a 300 mL glass of water, what is the pH of the solution and the percent dissociation?
Problem 99
- Write balanced net ionic equations and the corresponding equilibrium equations for the stepwise dissociation of the diprotic acid H2SeO4.
Problem 102
- Write balanced net ionic equations and the corresponding equilibrium equations for the stepwise dissociation of the triprotic acid H3PO4.
Problem 103
- Calculate the pH and the concentrations of all species present (H2CO3, HCO3-, CO32-, H3O+ , and OH-) in 0.010 M H2CO3 1Ka1 = 4.3 * 10-7; Ka2 = 5.6 * 10-112.
Problem 104
- Like sulfuric acid, selenic acid H2SeO4 is a diprotic acid that has a very large value of Ka1. Calculate the pH and the concentrations of all species present in 0.50 M H2SeO4 (Ka2 = 1.2 * 10^-22).
Problem 108
- Calculate the concentrations of H3O+ and SO4 2- in a solution prepared by mixing equal volumes of 0.2 M HCl and 0.6 M H2SO41Ka2 for H2SO4 is 1.2 * 10-22.
Problem 109
- Calculate the pH and the concentrations of all species present (H2C8H4O4, HC8H4O4-, C8H4O4 2-, H3O+, and OH-) in a 0.0250 M solution of phthalic acid, H2C8H4O4, with pKa1 = 2.89 and pKa2 = 5.512.
Problem 111
- Write a balanced net ionic equation and the corresponding equilibrium equation for the reaction of the following weak bases with water. (c) Cyanide ion, CN
Problem 112
- Which of the following compounds are more soluble in acidic solution than in pure water? Write a balanced net ionic equation for each dissolution reaction. (a) AgBr
Problem 113
- Strychnine 1C21H22N2O22, a deadly poison used for killing rodents, is a weak base having Kb = 1.8 * 10-6. Calculate the pH of a saturated solution of strychnine (16 mg/100 mL).
Problem 114
- Oxycodone 1C18H21NO42, a narcotic analgesic, is a weak base with pKb = 5.47. Calculate the pH and the concentrations of all species present (C18H21NO4, HC18H21NO4 + , H3O+ , and OH-) in a 0.002 50 M oxycodone solution.
Problem 118
- Morpholine C4H9NO is a weak organic base with pKb = 5.68. Calculate the pH and the concentrations of all species present (C4H9NO, HC4H9NO+, and OH-) in a 0.0100 M morpholine solution.
Problem 119
- Using values of Kb in Appendix C, calculate values of Ka for each of the following ions. (a) Propylammonium ion, C3H7NH3+
Problem 120
- Using values of Ka in Appendix C, calculate values of Kb for each of the following ions. (a) Fluoride ion, F-
Problem 121
- Nicotine 1C10H14N22 can accept two protons because it has two basic N atoms 1Kb1 = 1.0 * 10-6; Kb2 = 1.3 * 10-112. Calculate the values of Ka for the conjugate acids C10H14N2H+ and C10H14N2H22 + .
Problem 122
- Sodium benzoate (C6H5CO2Na) is used as a food preservative. Calculate the pH and the concentrations of all species present (Na+, C6H5COO-, C6H5COOH, H3O+, and OH-) in 0.050 M sodium benzoate; Ka for benzoic acid (C6H5COOH) is 6.5 * 10^-5.
Problem 123
- Write a balanced net ionic equation for the reaction of each of the following ions with water. In each case, identify the Brønsted–Lowry acids and bases and the conjugate acid– base pairs. (a) CH3NH3+
Problem 124
- Write a balanced net ionic equation for the principal reaction in solutions of each of the following salts. In each case, identify the Brønsted–Lowry acids and bases and the conjugate acid–base pairs. (a) Na2CO3
Problem 125
- Classify each of the following ions according to whether they react with water to give a neutral, acidic, or basic solution. (a) F-
Problem 126
- Classify each of the following salt solutions as neutral, acidic, or basic. See Appendix C for values of equilibrium constants. (a) Fe1NO323
Problem 127
- Calculate the concentrations of all species present and the pH in 0.10 M solutions of the following substances. See Appendix C for values of equilibrium constants. (b) Sodium acetate, Na1CH3CO22
Problem 128
- Calculate the pH and the percent dissociation of the hydrated cation in 0.020 M solutions of the following substances. See Appendix C for values of equilibrium constants. (a) Fe1NO322
Problem 129
- Calculate Ka for the cation and Kb for the anion in an aqueous NH4CN solution. Is the solution acidic, basic, or neutral?
Problem 130
- Classify each of the following salt solutions as acidic, basic, or neutral: (a) KBr (b) NaNO2 (c) NH4Br (d) ZnCl2 (e) NH4F
Problem 131
- The hydrated cation M1H2O26 3 + has Ka = 10-4, and the acid HA has Ka = 10-5. Identify the principal reaction in an aqueous solution of each of the following salts, and classify each solution as acidic, basic, or neutral. (a) NaA
Problem 132
- Classify each of the following salt solutions as neutral, acidic, or basic. See Appendix C for values of equilibrium constants. (a) NH4F (b) (NH4)2SO3
Problem 133