Chapter 15 – Acids and Bases
84. Predict the direction in which the equilibrium will lie for the reaction
H2SO3(aq) + HCO3– (aq) HSO3–(aq) + H2CO3(aq).
Ka1(H2SO3) = 1 10–2; Ka1(H2CO3) = 4.2 10–7
85. Predict the direction in which the equilibrium will lie for the reaction
C6H5COO– + HF C6H5COOH + F–.
Ka(C6H5COOH) = 6.5 10–5; Ka(HF) = 7.1 10–4
86. Predict the direction in which the equilibrium will lie for the reaction
H3PO4 + NO3– H2PO4– + HNO3. Ka(H3PO4) = 7.5 10–3
Chapter 15 – Acids and Bases
87. Which of the following yields a basic solution when dissolved in water?
I. NH3
II. Na2O
III. LiOH
IV. P4O10
88. Which of the following yields an acidic solution when dissolved in water?
I. NO2
II. NH4Cl
III. NaCl
IV. HNO2
Chapter 15 – Acids and Bases
89. Hard water deposits (calcium carbonate) have built up around your bathroom sink. Which
one of these substances would be most effective in dissolving the deposits?
90. In the reaction CaO(s) + SO2(g) CaSO3(s),
Chapter 15 – Acids and Bases
91. Which of these species will act as a Lewis acid?
92. Which of the following is both a Lewis Base and a Brønsted Acid?
Chapter 15 – Acids and Bases
93. Which of the following is both a Lewis Acid and Brønsted Acid?
94. The oxides SO2 and N2O5 will form the following acids in water, respectively.
95. The oxides CO2 and SO3 will form the following acids in water, respectively.
Chapter 15 – Acids and Bases
96. Hydrosulfuric acid is a diprotic acid, for which Ka1 = 5.7 10–8 and Ka2 = 1 10–19.
Determine the concentration of sulfide ion in a 0.10 M hydrosulfuric solution.
97. Calculate the concentration of oxalate ion (C2O42–) in a 0.175 M solution of oxalic acid
(C2H2O4). [For oxalic acid, Ka1 = 6.5 10–2, Ka2 = 6.1 10–5.]
Chapter 15 – Acids and Bases
98. Calculate the concentration of chromate ion (CrO42–) in a 0.450 M solution of chromic
acid (H2CrO4). [For chromic acid, Ka1 = 0.18, Ka2 = 3.2 10–7.]
99. Calculate the concentration of malonate ion (C3H2O42–) in a 0.200 M solution of malonic
acid (C3H4O4). [For malonic acid, Ka1 = 1.4 10–3, Ka2 = 2.0 10–6.]
Chapter 15 – Acids and Bases
100. For H3PO4, Ka1 = 7.3 10–3, Ka2 = 6.2 10–6, and Ka3 = 4.8 10–13. An aqueous solution
of NaH2PO4 therefore would be
101. For H3PO4, Ka1 = 7.3 10–3, Ka2 = 6.2 10–6, and Ka3 = 4.8 10–13. An aqueous solution
of Na3PO4 therefore would be
102. The salt hydrolysis reaction for NH4NO3 that represents the acidic or basic nature of the
solution is:
Chapter 15 – Acids and Bases
103. The salt hydrolysis reaction for CH3COONa that represents the acidic or basic nature of
the solution is:
104. Which one of these salts will form a neutral solution on dissolving in water?
105. Which one of these salts will form a basic solution on dissolving in water?
Chapter 15 – Acids and Bases
106. What is the pH of a 0.023 M solution of HCN (Ka = 4.9 x 10–10)?
107. What is the pH of a 0.11 M solution of C6H5OH (Ka = 1.3 x 10–10)?
Chapter 15 – Acids and Bases
108. What is the pH of a 0.30 M solution of HOCl (Ka = 3.5 x 10-8)?
109. What is the pH of a 0.080 M solution of the weak base pyridine (C5H5N; Kb = 1.7 x 10–
9)?
Chapter 15 – Acids and Bases
110. What is the pH of a 0.15 M solution of the weak base aniline (C6H5NH2; Kb = 3.8 x 10–
10)?
111. The pH of a 0.095 M solution of an unknown monoprotic acid is 5.42. Calculate the Ka
of the acid.
Chapter 15 – Acids and Bases
112. The pH of a 0.14 M solution of an unknown monoprotic acid is 5.85. Calculate the Ka of
the acid.
113. What is the pH of a 0.20 M solution of NH4Cl? [Kb(NH3) = 1.8 10–5]
Chapter 15 – Acids and Bases
114. Calculate the pH of a 0.021 M NaCN solution. [Ka(HCN) = 4.9 10–10]
115. Calculate the pH of a 0.20 M solution of NH4NO3. (Kb(NH3) = 1.8 x 10-5)
Chapter 15 – Acids and Bases
116. Calculate the pH of a 0.055 M solution of CH3COONa. (Ka(CH3COOH) = 1.8 x 10-5)
117. Calculate the pH of a 0.18 M solution of KNO2. (Ka (HNO2) = 4.5 x 10-4)
Chapter 15 – Acids and Bases
118.
Consider the weak bases below and their Kb values:
Arrange the conjugate acids of these weak bases in order of increasing acid strength.
119. Which one of these salts will form a basic solution upon dissolving in water?
Chapter 15 – Acids and Bases
120. Which one of these salts will form a basic solution upon dissolving in water?
121. Which one of these salts will form an acidic solution upon dissolving in water?
122. Which one of the following salts will form an acidic solution on dissolving in water?
Chapter 15 – Acids and Bases
123. The hydrolysis of NH4NO2 will result in which of the following types of solutions given:
(Ka(NH4+) = 5.6 x 10–10, Kb(NO2–) = 2.2 x 10–11)
124. The hydrolysis of NH4F will result in which of the following types of solutions given:
(Ka(NH4+) = 5.6 x 10–10, Kb(F–) = 1.4 x 10–11)
125. What mass of ammonium chloride must be added to 250. mL of water to give a solution
with pH = 4.85? [Kb(NH3) = 1.8 10–5]
Chapter 15 – Acids and Bases
126. What mass of sodium nitrite must be added to 350. mL of water to give a solution with
pH = 8.40? [Ka(HNO2) = 5.6 10–4]
127. What mass of potassium hypochlorite must be added to 450. mL of water to give a
solution with pH = 10.20? [Ka(HClO) = 4.0 10–8]
Chapter 15 – Acids and Bases
128. What is the pH of a solution prepared by mixing 100. mL of 0.0500 M HCl with 300.
mL of 0.500 M HF? [Ka(HF) = 7.1 10–4]
129. What is the pH of a solution prepared by mixing 50.0 mL of 0.300 M HCl with 450.0
mL of 0.400 M HIO3? [Ka(HIO3) = 1.6 10–1]