SOLVED

18.2 Algorithmic Questions 1) Identify the pH of normal blood. A) 6.9 B) 7.1 C) 7.4 D) 7.6 E) 7.9 2) Which of the following solutions is a good buffer system? A) a solution that is 0.10 M NaCl and 0.10 M HCl B) a solution that is 0.10 M HCN and 0.10 M LiCN C) a solution that is 0.10 M NaOH and 0.10 M HNO3 D) a solution that is 0.10 M HNO3 and 0.10 M NaNO3 E) a solution that is 0.10 M HCN and 0.10 M KBr 3) Which of the following solutions is a good buffer system? A) a solution that is 0.10 M HC2H3O2 and 0.10 M LiC2H3O2 B) a solution that is 0.10 M HBr and 0.10 M LiC2H3O2 C) a solution that is 0.10 M HI and 0.10 M NH4+ D) a solution that is 0.10 M LiOH and 0.10 M KOH E) None of the above are buffer systems. 4) Which one of the following statements is true? A) A buffer is an aqueous solution composed of two strong bases. B) A buffer can absorb an unlimited amount of base. C) A buffer resists pH change by neutralizing added acids and bases. D) A buffer does not change pH when strong base is added. E) All of the above are true. 5) A solution is prepared by dissolving 0.23 mol of nitrous acid and 0.27 mol of sodium nitrite in water sufficient to yield 1.00 L of solution. The addition of 0.05 mol of NaOH to this buffer solution causes the pH to increase slightly. The pH does not increase drastically because the NaOH reacts with the ________ present in the buffer solution. The Ka of nitrous acid is 4.5 × 10-4. A) H2O B) H3O+ C) nitrite D) nitrous acid 6) A solution is prepared by dissolving 0.23 mol of butanoic acid and 0.27 mol of sodium butanoate in water sufficient to yield 1.00 L of solution. The addition of 0.05 mol of HCl to this buffer solution causes the pH to drop slightly. The pH does not decrease drastically because the HCl reacts with the ________ present in the buffer solution. The Ka of butanoic acid is 1.36 × 10-3. A) H2O B) H3O+ C) butanoate ion D) butanoic acid 7) Calculate the pH of a solution that is 0.111 M in sodium formate (NaHCO2) and in formic acid (HCO2H). The Ka of formic acid is 1.77 × 10-4. A) 3.387 B) 4.103 C) 14.36 D) 10.61 E) 5.296 8) Calculate the pH of a solution that is 0.210 M in nitrous acid () and 0.290 M in potassium nitrite (). The acid dissociation constant of nitrous acid is 4.50 × . A) 3.487 B) 3.210 C) 13.86 D) 10.51 E) 4.562 9) Calculate the percent ionization of nitrous acid in a solution that is 0.205 M in nitrous acid and 0.295 M in potassium nitrite (). The acid dissociation constant of nitrous acid is A) 59.0 B) 0.151 C) 17.1 D) 2.72 × E) 3.508 10) Calculate the percent ionization of nitrous acid in a solution that is 0.169 M in nitrous acid. The acid dissociation constant of nitrous acid is 4.50 × 10-4. A) 7.61 × 10-5 B) 0.0450 C) 5.16 D) 0.743 E) 3.76