Ch.16 - Aqueous Equilibria: Acids & Bases
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Problem 79b
Which of the indicators given in Figure 16.5, methyl violet, bromcresol green, phenol red, or thymolphthalein, would be most appropriate to detect a pH change from: (b) 8 to 10?
Problem 79c
Which of the indicators given in Figure 16.5, methyl violet, bromcresol green, phenol red, or thymolphthalein, would be most appropriate to detect a pH change from: (c) 2 to 0?
- Which of the following species behave as strong acids or as strong bases in aqueous solution? (a) HNO2 (b) HNO3(c) NH4+ (d) Cl-
Problem 80
- Which of the following species behave as strong acids or strong bases in aqueous solution? (a) H- (b) O2- (c) H2SO4 (d) CsOH
Problem 81
- Calculate the pH of the following solutions: (c) 0.075 M NaOH
Problem 83
Problem 84a
Calculate the pH of solutions prepared by: (a) Dissolving 4.8 g of lithium hydroxide in water to give 250 mL of solution.
Problem 84d
Calculate the pH of solutions prepared by: (d) Mixing 100.0 mL of 2.0 * 10-3 M HCl and 400.0 mL of 1.0 * 10-3 M HClO4. (Assume that volumes are additive.)
- Calculate the pH of solutions prepared by: (a) Dissolving 0.20 g of sodium oxide in water to give 100.0 mL of solution.
Problem 85
- How many grams of CaO should be dissolved in sufficient water to make 1.00 L of a solution with a pH of 10.50?
Problem 86
- How many grams of SrO should be dissolved in sufficient water to make 2.00 L of a solution with a pH of 10.0?
Problem 87
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