Raymond Chang 10th edition Chapter 16 Chemistry Raymond Chang 10th edition Chapter 16 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Question 1 The conjugate base of the diprotic acid sulfuric acid is the hydrogen sulfate ion. Which of the following is true? A) A solution of sodium hydrogen sulfate in water would be basic. B) A solution of sulfuric acid and sodium hydrogen sulfate in water would be a buffer. C) A solution of sodium hydrogen sulfate and sodium sulfate in water would be a buffer. D) All of the above.

Question 2 In order to produce a buffer system that has a pH that is one pH unit lower than the pKa of the conjugate acid the ratio of conjugate base to conjugate acid must be A) 1/10. B) 10/1. C) ½. D) 2/1.

Question 3 Which of the following titrations would have an acidic endpoint? A) Hydrochloric acid titrated with barium hydroxide. B) Sodium nitrite titrated with hydrochloric acid. C) Ammonium chloride titrated with sodium hydroxide. D) Nitric acid titrated with sodium hydroxide.

Question 4 Calcium carbonate deposits from hard water could best be dissolved by which of the following? A) Tap water B) Drain cleaner containing sodium hydroxide C) Ammonia solution D) Vinegar

Question 5 Silver ions can be separated from a solution containing silver nitrate and sodium nitrate by adding hydroiodic acid because A) basic nitrate ions react with the added acid forming water. B) silver iodide precipitates out of the solution leaving the sodium ions dissolved in the solution. C) sodium iodide precipitates out of the solution leaving behind the silver ions. D) the iodide ions from the acid primarily react with the nitrate ions from silver nitrate.

Question 6 The solubility rules state that all common salts containing the group 1A metal ions are soluble. This means that there is no limit to how much of these salts can be dissolved in water. A) True B) False

Question 7 The solubility rules state that common salts containing carbonate ions are generally insoluble (with some exceptions). This means that for the ones that are classified as insoluble, none of the salt can be dissolved no matter how much water is present. A) True B) False

Question 8 If adding hydrochloric acid to a solution containing a single unknown salt results in a precipitate, which of the following could be the positive ion of the salt? A) Copper(II) ion B) Potassium ion C) Silver ion D) None of the above

Question 9 Phenolphthalein is a common acid-base indicator that changes color between pH 8.3 and 10. This would not be a useful indicator choice for the titration of A) ammonia with hydrochloric acid. B) hydrofluoric acid with potassium hydroxide. C) sodium hydrogen sulfate with sodium hydroxide. D) hydrochloric acid with potassium hydroxide.

Question 10 Adding ammonia to a precipitate of silver chloride causes the precipitate to redissolve. This happens because A) ammonia is a Bronsted base and silver chloride a Bronsted acid. B) ammonia is slightly acidic so it reacts with the slightly basic chloride ions. C) ammonia forms a soluble complex ion with the silver. D) the Ksp for the silver chloride changes in the presence of ammonia.

Question 11 Which of the following is the strongest conjugate base? A) Cl- B) NO3- C) HSO4- D) CH3COO- E) OH-

Question 12 Which of the following must be true for a solution to be considered acidic? A) [H+] > [OH-] B) [H+] < [OH-] C) pH = 0 D) Kw = [H+]/[OH-] E) none of the above

Question 13 When pure water is heated, the concentration of the H+ ion increases. This means that A) water becomes more acidic when heated. B) water becomes more basic when heated. C) none of these.

Question 14 Which of the following makes a buffer when added to a solution of ammonium chloride? A) HCl B) NH4Cl C) NaCH3COO D) CH3COOH E) NH3

Question 15 Given a 5.0 g sample of vinegar having a mass percentage of acetic acid equal to 9.1 %, calculate what volume of NaOH solution of molarity 0.82 M will be necessary to titrate this vinegar sample. A) 8.96 mL B) 9.2 mL C) 9.246 mL D) 0.108 mL E) 9.0 mL

Question 16 Calculate the solubility of silver chloride in g/mL given that Ksp = 1.6 x 10-10 A) 1.26 x 10-5 B) 2.015 x 10-3 C) 1.9 x 10-3 D) 2.7 x 10-8 E) none of the above

Question 17 Which of the following ions in aqueous solution cannot be precipitated by the addition of silver nitrate? A) fluoride B) chloride C) bromide D) iodide E) carbonate

Question 18 Which of the following ions could interfere in the precipitation of Ag+ from an aqueous solution? A) K+ B) Au+ C) Zn2+ D) Hg2+ E) Hg22+

Question 19 Two unmarked bottles contain colorless solutions Question 19 Two unmarked bottles contain colorless solutions. One contains mercuric chloride, the other contains potassium iodide. The bottles are unlabeled. If the only equipment available are empty test tubes, is it possible to positively identify the two solutions? A) Yes B) No C) Only if additional equipment and chemicals are available

Question 20 Which of the following is true of a buffered solution? A) Any OH- ions added will react with a weak acid already in solution. B) The solution will not change its pH very much even if a concentrated acid is added. C) The solution will not change its pH very much even if a strong base is added. D) Any H+ ions added will react with a conjugate base of a weak acid already in solution. E) all of the above

Answer Key – Chapter 16 C A B D D A C E B