Final Test Bank Answers Chapter 14 Acid-Base Equilibria

Supplemental Test Items to accompany OpenStax Chemistry. Note that not all chapters of OpenStax Chemistry have accompanying test items. Building on the community-oriented nature of OpenStax resources, we invite you to submit items to be considered for future inclusion.

Chapter 14: Acid-Base Equilibria

1. Which of the following is an electronic device used to measure the hydrogen ion activity in aqueous solutions? (Outcome # 7) (DOK 1)
2. pH meter
3. potentiometer
4. ammeter
5. Which of the following is a typical type of electrode found on a pH meter? (Outcome # 7) (DOK 1)
6. gold electrode
7. glass electrode
8. silver electrode
9. When titrating a weak acid with a strong base, approximately where would the pH be observed when reaching the equivalence point? (Outcome # 4) (DOK 2)
10. at the equivalence point, the pH is greater than 7
11. at the equivalence point, the pH is equal to 7
12. at the equivalence point, the pH is less than 7
13. When titrating a weak base with a strong acid, approximately where would the pH be observed when reaching the equivalence point? (Outcome # 4) (DOK 2) (Paired item 1)
14. at the equivalence point, the pH is greater than 7
15. at the equivalence point, the pH is equal to 7
16. at the equivalence point, the pH is less than 7
17. When titrating a strong acid with a strong base, approximately where would the pH be observed when reaching the equivalence point? (Outcome # 4) (DOK 2) (Paired item 2)
18. at the equivalence point, the pH is greater than 7
19. at the equivalence point, the pH is equal to 7
20. at the equivalence point, the pH is less than 7
21. What are the products formed at the equivalence point when titrating a strong acid with a strong base? (Outcome # 4) (DOK 2)
22. salt and water
23. the solution is neutral, so water only
24. no products are formed
25. Phenolphthalein can be used as an _____ in acid-base titrations. (Outcome # 4) (DOK 1)
26. equivalence point
27. end-point
28. indicator
29. Phenolphthalein can be used as an indicator in acid-base titrations. When a few drops are added to an acidic solution which is then titrated with a strong base, the color of the solution changes from _____ to _____. (Outcome # 4) (DOK 1)
30. colorless; pink
31. pink; colorless
32. colorless; red
33. When blue litmus paper is in contact with an acid, the litmus paper will turn _____. (Outcome # 4) (DOK 1)
34. orange
35. red
36. green
37. When red litmus paper is in contact with a base, the litmus paper will turn _____. (Outcome # 4) (DOK 1) (Paired item 1)
38. orange
39. green
40. blue
41. Which of the following is a diprotic acid? (Outcome # 3) (DOK 1)
42. H₃PO₄
43. H₂PO₄^-
44. HPO₄^2-
45. Which of the following is an amphiprotic substance? (Outcome # 3) (DOK 1)
46. H₃PO₄
47. PO₄^3-
48. HPO₄^2-
49. What is the conjugate base that is formed when carbonic acid is dissolved in water? (Outcome # 3) (DOK 2)
50. H₃O⁺
51. HCO₃^-
52. CO₃^2-
53. When phosphoric acid is dissolved in water, what is the conjugate acid that is formed? (Outcome # 3) (DOK 2)
54. H₂PO₄^-
55. H₃O⁺
56. HPO₄^2-
57. What is the conjugate base that is formed upon the addition of carbonic acid to water? (Outcome # 3) (DOK 2)
58. HCO₃^-
59. H₃O⁺
60. CO₃^2-
61. Rank the following oxyanions in order of increasing basicity: ClO₄^-, ClO₂^-, ClO^-, ClO₃^-. (Outcome # 3) (DOK 2)
62. ClO₄^-, ClO^-, ClO₂^-, ClO₃^-
63. ClO^-, ClO₂^-, ClO₃^-, ClO₄^-
64. ClO₄^-, ClO₃^-, ClO₂^-, ClO^-
65. Rank the following oxoacids in order of increasing acidity: HClO₂, HClO₄, HClO, HClO₃. (Outcome # 3) (DOK 2)
66. HClO, HClO₂, HClO₃, HClO₄
67. HClO₄, HClO₂, HClO, HClO₃
68. HClO₄, HClO₃, HClO₂, HClO
69. What is the pH of a solution if 10 mL of a 1 M HCl solution is added to 10 mL of a 1 M NaOH solution? (Outcome # 10) (DOK 2)
70. 14
71. 7
72. 0
73. If 10 mL of a 1 M HI solution is added to 5 mL of a 1 M KOH solution, the resulting solution would be _____. (Outcome # 10) (DOK 2)
74. acidic
75. basic
76. neutral
77. If 3 mL of a 0.5 M HBr solution is added to 20 mL of a 0.5 M NaOH solution, the resulting solution would be _____. (Outcome # 10) (DOK 2) (Paired item 1)
78. acidic
79. basic
80. neutral
81. What is the hydronium concentration of a solution at pH 7? (Outcome # 10) (DOK 1)
82. 1 x 10⁺⁷ M
83. 1 x 10^-14 M
84. 1 x 10^-7 M
85. A student titrates 50.0 mL of an unknown concentration of HI with 85 mL of a 1.0 M solution of NaOH to reach the equivalence point. What is the pH of the HI solution? (Outcome # 10) (DOK 3)
86. -0.23
87. 0.23
88. 1.7
89. A student titrates a 25 mL of an unknown concentration of HCl with 35 mL of a 0.890 M solution of KOH to reach the equivalence point. What is the pH of the HCl solution? (Outcome # 10) (DOK 3) (Paired item 1)
90. -0.10
91. 0.10
92. 1.2
93. A student discovers a bottle of a highly corrosive monoprotic acid with the label partially destroyed. How can the concentration of the unknown acid be determined without using a pH meter? (Outcome # 10) (DOK 3)
94. The student can set-up a titration experiment, where a standardized NaOH solution is used to titrate the unknown strong acid. The moles of OH^- added would be equal to moles of H⁺ in the unknown at the half-way point, therefore, the concentration of the unknown can be calculated.
95. The student can set-up a titration experiment, where a standardized NaOH solution is used to titrate the unknown strong acid. The moles of OH^- added would be equal to moles of H⁺ in the unknown at the equivalence point, therefore, the concentration of the unknown can be calculated.
96. The student can set-up a titration experiment, where a standardized NaOH solution is used to titrate the unknown strong acid. The pH at the equivalence point should be 7 since this is a neutralization reaction, therefore, the concentration of the unknown acid is 1 x 10^-7 M.
97. A student discovers a bottle of NaOH with a partially destroyed label. How can the concentration be determined without using a pH meter? (Outcome # 10) (DOK 3)
98. The student can set-up a titration experiment, where a standardized HCl solution is used to titrate the NaOH. The moles of H⁺ and OH^- are equal at the equivalence point, therefore, the concentration of NaOH can be calculated.
99. The student can set-up a titration experiment, where a standardized HCl solution is used to titrate the NaOH. The pH at the equivalence point should be 7 since this is a neutralization reaction, therefore, the concentration of NaOH is 1 x 10^-7 M.
100. The student can set-up a titration experiment, where a standardized NaOH solution is used to titrate HCl. The moles of H⁺ and OH^- are equal at the equivalence point, therefore, the concentration of NaOH can be calculated.
101. What is the pH of 0.048 M solution of hydrochloric acid? (Outcome # 7) (DOK 1)
102. 0.32
103. 4.8
104. 1.3
105. What is the pH of 0.014 M solution of hydroiodic acid? (Outcome # 7) (DOK 1) (Paired item 1)
106. 1.4
107. 1.9
108. 0.85
109. What is the pH of deionized water? (Outcome # 7) (DOK 1)
110. pH = 7
111. pH < 7
112. pH > 7
113. What is the pH of 0.48 M HCl solution? (Outcome # 2) (DOK 1)
114. 0.32
115. -0.32
116. 13.68
117. What is the pH of 8.1 x 10^-5 M HClO₄ solution? (Outcome # 2) (DOK 1) (Paired item 1)
118. 9.91
119. 4.09
120. -4.09
121. What is the hydroxide ion concentration for a 23 % (m/v) HNO₃ solution? (Outcome # 2) (DOK 3)
122. 10.35 M
123. 3.65 M
124. 2.74 x 10^-15 M
125. Blood is considered a buffered solution. What is the pH range of blood? (Outcome # 2) (DOK 1)
126. 7.35 - 7.45
127. 6.35 - 6.45
128. 8.35 - 8.45
129. What instrument can be used to measure the hydrogen ion concentration in solutions? (Outcome # 2) (DOK 1)
130. ammeter
131. pH meter
132. potentiometer
133. Which acid has a lower pH? (Outcome # 5) (DOK 2)
134. 1.0 M acetic acid
135. 0.50 M acetic acid
136. 0.25 M acetic acid
137. Which acid has a higher hydrogen ion concentration? (Outcome # 5) (DOK 2)
138. 1.0 M HCl
139. 0.050 M HNO₃
140. 1.25 M HBr
141. What is the base in the following reaction: HCl (aq) + H₂O (l) 🡪 Cl^- (aq) + H₃O⁺ (aq)? (Outcome # 5) (DOK 2)
142. Cl^-
143. H₃O⁺
144. H₂O
145. What is the conjugate acid in the following reaction: HCl (aq) + H₂O (l) 🡪 Cl^- (aq) + H₃O⁺ (aq)? (Outcome # 5) (DOK 2)
146. Cl^-
147. H₃O⁺
148. H₂O
149. What is the conjugate base in the following reaction: HCl (aq) + H₂O (l) 🡪 Cl^- (aq) + H₃O⁺ (aq)? (Outcome # 5) (DOK 2) (Paired item 1)
150. Cl^-
151. H₃O⁺
152. H₂O
153. What is the conjugate base of HSO₄^-? (Outcome # 5) (DOK 2)
154. H₂SO₄
155. SO₄^2-
156. SO₄^-
157. What is the conjugate acid of HSO₄^-? (Outcome # 5) (DOK 2)
158. H₂SO₄
159. SO₄^2-
160. H₂SO₄^-
161. Write the equilibrium expression for the autoionization of water. (Outcome # 3) (DOK 3)
162. K_w = [H₃O⁺] [OH^-] / [H₂O]²
163. K_w = [H₃O⁺] [OH^-]
164. K_w = [H₂O]² / [H₃O⁺] [OH^-]
165. What is the pOH of a solution that has a pH of 7? (Outcome # 2) (DOK 1)
166. 7
167. 14
168. 0
169. What is the pOH of a solution that has a pH of 2? (Outcome # 2) (DOK 1) (Paired item 1)
170. 12
171. 7
172. 14
173. Which acid has the lowest hydroxide ion concentration? (Outcome # 5) (DOK 2)
174. 0.010 M HCl
175. 0.050 M HNO₃
176. 0.015 M HBr
177. What is the conjugate base in the following reaction: HI (aq) + H₂O (l) 🡪 I^- (aq) + H₃O⁺ (aq)? (Outcome # 5) (DOK 2)
178. I^-
179. H₃O⁺
180. H₂O
181. What is the acid in the following reaction: NH₃ (aq) + H₂O (l) 🡪 NH₄⁺ (aq) + OH^- (aq)? (Outcome # 5) (DOK 2)
182. NH₃
183. NH₄⁺
184. H₂O