Answer at the bottom of the page
17.1 Multiple-Choice Questions
1) Which one of the following pairs cannot be mixed together to form a buffer solution?
A) HONH2, HONH3Cl
B) NaCl, HCl
C) RbOH, HF
D) KOH, HNO2
E) H2SO3, KHSO3
2) Which one of the following pairs cannot be mixed together to form a buffer solution?
A) NH3, NH4Cl
B) NaC2H3O2, HCl (C2H3O2- = acetate)
C) RbOH, HBr
D) KOH, HF
E) H3PO4, KH2PO4
3) Which one of the following pairs cannot be mixed together to form a buffer solution?
A) C5H5N, C5H5NHCl
B) HC2H3O2, NaOH (C2H3O2- = acetate)
C) KOH, HI
D) NH2CH3, HCl
E) NaClO, HNO3
4) A solution containing which one of the following pairs of substances will be a buffer solution?
A) NaI, HI
B) KBr, HBr
C) RbCl, HCl
D) CsF, HF
E) none of the above
5) A solution containing which one of the following pairs of substances will be a buffer solution?
A) KI, HI
B) AgBr, HBr
C) CuCl, HCl
D) CsI, HI
E) none of the above
6) What change will be caused by addition of a small amount of HCl to a solution containing fluoride ions and hydrogen fluoride?
A) The concentration of hydronium ions will increase significantly.
B) The concentration of fluoride ions will increase as will the concentration of hydronium ions.
C) The concentration of hydrogen fluoride will decrease and the concentration of fluoride ions will increase.
D) The concentration of fluoride ion will decrease and the concentration of hydrogen fluoride will increase.
E) The fluoride ions will precipitate out of solution as its acid salt.
7) The Henderson-Hasselbalch equation is __________.
A) [H+] = Ka +
B) pH = pKa – log
C) pH = pKa + log
D) pH = pKa + log
E) pH = log
8) In a solution, when the concentrations of a weak acid and its conjugate base are equal,
A) the system is not at equilibrium.
B) the buffering capacity is significantly decreased.
C) the -log of the [H+] and the -log of the Ka are equal.
D) all of the above are true.
9) Of the following solutions, which has the greatest buffering capacity?
A) 0.821 M HF and 0.217 M NaF
B) 0.821 M HF and 0.909 M NaF
C) 0.100 M HF and 0.217 M NaF
D) 0.121 M HF and 0.667 M NaF
E) They are all buffer solutions and would all have the same capacity.
10) Of the following solutions, which has the greatest buffering capacity?
A) 0.521 M HC2H3O2 and 0.217 M NaC2H3O2
B) 0.821 M HC2H3O2 and 0.713 M NaC2H3O2
C) 0.365M HC2H3O2 and 0.497 M NaC2H3O2
D) 0.121 M HC2H3O2 and 0.116 M NaC2H3O2
11) Of the following solutions, which has the greatest buffering capacity?
A) 0.543 M NH3 and 0.555 M NH4Cl
B) 0.087 M NH3 and 0.088 M NH4Cl
C) 0.234 M NH3 and 0.100 M NH4Cl
D) 0.100 M NH3 and 0.455 M NH4Cl
E) They are all buffer solutions and would all have the same capacity.
12) The addition of hydrofluoric acid and __________ to water produces a buffer solution.
A) HCl
B) NaNO3
C) NaF
D) NaCl
E) NaBr
13) The addition of hydrofluoric acid and __________ to water produces a buffer solution.
A) HCl
B) NaNO3
C) NaCl
D) NaOH
E) NaBr
14) The addition of hydrochloric acid and __________ to water produces a buffer solution.
A) HC6H5O
B) NaOH
C) NH3
D) HNO3
E) NaNO3
15) The addition of hydrochloric acid and __________ to water produces a buffer solution.
A) HC6H5O
B) NaOH
C) NaCl
D) C2H5NH2
E) none of the above
16) The addition of sodium hydroxide and __________ to water produces a buffer solution.
A) HCl
B) NaC2H3O2
C) NaF
D) NH3
E) none of the above
17) Which of the following could be added to a solution of sodium acetate to produce a buffer?
A) acetic acid only
B) acetic acid or hydrochloric acid
C) hydrochloric acid only
D) potassium acetate only
E) sodium chloride or potassium acetate
18) Which of the following could be added to a solution of potassium fluoride to prepare a buffer?
A) sodium hydroxide
B) potassium acetate
C) hydrochloric acid
D) sodium fluoride
E) ammonia
19) Which of the following could be added to a solution of acetic acid to prepare a buffer?
A) sodium hydroxide
B) hydrochloric acid
C) nitric acid
D) more acetic acid
E) None of the above can be added to an acetic acid solution to prepare a buffer.
20) Which of the following could be added to a solution of acetic acid to prepare a buffer?
A) sodium acetate only
B) sodium acetate or sodium hydroxide
C) nitric acid only
D) hydrofluoric acid or nitric acid
E) sodium hydroxide only
21) The primary buffer system that controls the pH of the blood is the __________ buffer system.
A) carbon dioxide, carbonate
B) carbonate, bicarbonate
C) carbonic acid, carbon dioxide
D) carbonate, carbonic acid
E) carbonic acid, bicarbonate
22) What are the principal organs that regulate the pH of the carbonic acid-bicarbonate buffer system in the blood?
A) kidneys, liver
B) lungs, kidneys
C) spleen, liver
D) lungs, skin
E) brain stem, heart
23) Human blood is __________.
A) neutral
B) very basic
C) slightly acidic
D) very acidic
E) slightly basic
24) Which one of the following will cause hemoglobin to release oxygen?
A) increase in pH
B) decrease in pH
C) decrease in temperature
D) decrease in CO2 concentration
E) increase in O2 concentration
25) A 25.0 mL sample of a solution of an unknown compound is titrated with a 0.115 M NaOH solution. The titration curve above was obtained. The unknown compound is __________.
A) a strong acid
B) a strong base
C) a weak acid
D) a weak base
E) neither an acid nor a base
26) A 25.0 mL sample of a solution of a monoprotic acid is titrated with a 0.115 M NaOH solution. The titration curve above was obtained. The concentration of the monoprotic acid is about __________ mol/L.
A) 25.0
B) 0.0600
C) 0.240
D) 0.120
E) 0.100
27) A 25.0 mL sample of a solution of a monoprotic acid is titrated with a 0.115 M NaOH solution. The titration curve above was obtained. Which of the following indicators would be best for this titration?
A) methyl red
B) bromthymol blue
C) thymol blue
D) phenolpthalein
E) bromocresol purple
Consider the following table of Ksp values.
28) Which compound listed below has the greatest molar solubility in water?
A) CdCO3
B) Cd(OH)2
C) AgI
D) CaF2
E) ZnCO3
29) Which compound listed below has the smallest molar solubility in water?
A) ZnCO3
B) Cd(OH)2
C) CdCO3
D) AgI
E) CaF2
30) The molar solubility of __________ is not affected by the pH of the solution.
A) Na3PO4
B) NaF
C) KNO3
D) ACl3
E) MnS
31) In which of the following aqueous solutions would you expect AgCl to have the lowest solubility?
A) pure water
B) 0.020 M BaCl2
C) 0.015 NaCl
D) 0.020 AgNO3
E) 0.020 KCl
32) In which of the following aqueous solutions would you expect AgCl to have the highest solubility?
A) pure water
B) 0.020 M BaCl2
C) 0.015 NaCl
D) 0.020 AgNO3
E) 0.020 KCl
33) In which of the following aqueous solutions would you expect AgBr to have the lowest solubility?
A) pure water
B) 0.20 M NaBr
C) 0.10 M AgNO3
D) 0.15 M KBr
E) 0.10 M LiBr
34) In which of the following aqueous solutions would you expect AgBr to have the highest solubility?
A) 0.10 M LiBr
B) 0.10 M AgNO3
C) 0.20 M NaBr
D) 0.15 M KBr
E) pure water
35) In which of the following aqueous solutions would you expect CuBr to have the highest solubility?
A) pure water
B) 0.10 M AgNO3
C) 0.20 M NaBr
D) 0.15 M KBr
E) 0.10 M LiBr
36) In which of the following aqueous solutions would you expect PbCl2to have the lowest solubility?
A) 0.020 M KCl
B) 0.020 M BaCl2
C) 0.015 M PbNO3
D) pure water
E) 0.015 M NaCl
37) In which one of the following solutions is silver chloride the most soluble?
A) 0.181 M HCl
B) 0.0176 M NH3
C) 0.744 M LiNO3
D) pure water
E) 0.181 M NaCl
38) Which one of the following is not amphoteric?
A) Al(OH)3
B) Ca(OH)2
C) Cr(OH)3
D) Zn(OH)2
E) Sn(OH)2
39) For which salt should the aqueous solubility be most sensitive to pH?
A) Ca(NO3)2
B) CaF2
C) CaCl2
D) CaBr2
E) CaI2
40) Which below best describe(s) the behavior of an amphoteric hydroxide in water?
A) With conc. aq. NaOH, its suspension dissolves.
B) With conc. aq. HCl, its suspension dissolves.
C) With conc. aq. NaOH, its clear solution forms a precipitate.
D) With conc. aq. HCl, its clear solution forms a precipitate.
E) With both conc. aq. NaOH and conc. aq. HCl, its suspension dissolves.
41) Of the substances below, __________ will decrease the solubility of Pb(OH)2 in a saturated solution.
A) NaNO3
B) H2O2
C) HNO3
D) Pb(NO3)2
E) NaCl
42) Why does fluoride treatment render teeth more resistant to decay?
A) Fluoride kills the bacteria in the mouth that make the acids that decay teeth.
B) Fluoride stimulates production of tooth enamel to replace that lost to decay.
C) Fluoride reduces saliva production, keeping teeth drier and thus reducing decay.
D) Fluoride converts hydroxyapatite to fluoroapatite that is less reactive with acids.
E) Fluoride dissolves plaque, reducing its decaying contact with teeth.
43) A result of the common-ion effect is __________.
A) that some ions, such as Na+ (aq), frequently appear in solutions but do not participate in solubility equilibria
B) that common ions, such as Na+ (aq), don’t affect equilibrium constants
C) that the selective precipitation of a metal ion, such as Ag+, is promoted by the addition of an appropriate counterion (X-) that produces a compound (AgX) with a very low solubility
D) that ions such as K+ and Na+ are common ions, so that their values in equilibrium constant expressions are always 1.00
E) that common ions precipitate all counter-ions
17.2 Bimodal Questions
1) The Ka of benzoic acid is 6.30 × 10-5. The pH of a buffer prepared by combining 50.0 mL of 1.00 M potassium benzoate and 50.0 mL of 1.00 M benzoic acid is __________.
A) 1.705
B) 0.851
C) 3.406
D) 4.201
E) 2.383
2) Calculate the pH of a solution prepared by dissolving 0.150 mol of benzoic acid and 0.300 mol of sodium benzoate in water sufficient to yield 1.00 L of solution. The Ka of benzoic acid is 6.30 × 10-5.
A) 2.516
B) 3.892
C) 4.502
D) 10.158
E) 4.195
3) Calculate the pH of a solution prepared by dissolving 0.150 mol of acetic acid and 0.300 mol of sodium acetate in water sufficient to yield 1.00 L of solution. The Ka of acetic acid is 1.76 × 10-5.
A) 2.516
B) 3.892
C) 4.502
D) 10.158
E) 5.056
4) The pH of a solution prepared by dissolving 0.350 mol of solid methylamine hydrochloride (CH3NH3Cl) in 1.00 L of 1.10 M methylamine (CH3NH2) is __________. The Kb for methylamine
is 4.40 × 10-4. (Assume the final volume is 1.00 L.)
A) 1.66
B) 2.86
C) 10.28
D) 11.14
E) 10.61
5) The pH of a solution prepared by dissolving 0.350 mol of solid dimethylamine hydrochloride ((CH3)2NH2Cl) in 1.00 L of 1.10 M dimethylamine ((CH3)2NH) is __________. The Kb for methylamine is 5.40 × 10-4. (Assume the final volume is 1.00 L.)
A) 1.66
B) 2.77
C) 11.23
D) 11.14
E) none of the above
6) A 25.0 mL sample of 0.723 M HClO4 is titrated with a 0.27 M KOH solution. The H3O+ concentration after the addition of 80.0 mL of KOH is __________ M.
A) 0.4
B) 1 × 10-7
C) 0.7
D) 3 × 10-13
E) 4 × 10-2
7) The pH of a solution prepared by mixing 50.0 mL of 0.125 M KOH and 50.0 mL of 0.125 M HCl is __________.
A) 6.29
B) 7.00
C) 8.11
D) 5.78
E) 0.00
8) The pH of a solution prepared by mixing 40.0 mL of 0.125 M Mg(OH)2 and 150.0 mL of 0.125 M HCl is __________.
A) 6.29
B) 4.11
C) 1.14
D) 5.78
E) 1.34
9) The pH of a solution prepared by mixing 50.0 mL of 0.125 M NaOH and 40.0 mL of 0.125 M HNO3 is __________.
A) 13.29
B) 7.00
C) 8.11
D) 11.00
E) none of the above
10) A 50.0 mL sample of an aqueous H2SO4 solution is titrated with a 0.375 M NaOH solution. The equivalence point is reached with 62.5 mL of the base. The concentration of H2SO4 is __________ M.
A) 0.234
B) 0.469
C) 0.150
D) 0.300
E) 0.938
11) The concentration of iodide ions in a saturated solution of lead (II) iodide is __________ M. The solubility product constant of PbI2 is 1.4 × 10-8.
A) 3.8 × 10-4
B) 3.0 × 10-3
C) 1.5 × 10-3
D) 3.5 × 10-9
E) 1.4 × 10-8
12) The concentration of fluoride ions in a saturated solution of barium fluoride is __________ M. The solubility product constant of BaF2 is 1.7 × 10-6.
A) 3.8 × 10-4
B) 3.0 × 10-3
C) 1.5 × 10-2
D) 7.5 × 10-3
E) 1.4 × 10-4
13) The concentration of iodide ions in a saturated solution of silver iodide is __________ M. The solubility product constant of AgI is 8.3 × 10-17.
A) 3.8 × 10-11
B) 3.0 × 10-10
C) 9.1 × 10-9
D) 3.5 × 10-9
E) 1.4 × 10-8
14) The solubility of lead (II) chloride (PbCl2) is 1.6 × 10-2 M. What is the Ksp of PbCl2?
A) 5.0 × 10-4
B) 4.1 × 10-6
C) 3.1 × 10-7
D) 1.6 × 10-5
E) 1.6 × 10-2
15) The solubility of manganese (II) hydroxide (Mn(OH)2) is 2.2 × 10-5 M. What is the Ksp of MnOH)2?
A) 1.1 × 10-14
B) 4.3 × 10-14
C) 2.1 × 10-14
D) 4.8 × 10-10
E) 2.2 × 10-5
16) Determine the Ksp for magnesium hydroxide (Mg(OH)2) where the solubility of Mg(OH)2
is 1.4 × 10-4 M.
A) 2.7 × 10-12
B) 1.1 × 10-11
C) 2.0 × 10-8
D) 3.9 × 10-8
E) 1.4 × 10-4
17) Calculate the maximum concentration (in M) of silver ions (Ag+) in a solution that contains 0.025 M of CO32-. The Ksp of Ag2CO3 is 8.1 × 10-12.
A) 1.8 × 10-5
B) 1.4 × 10-6
C) 2.8 × 10-6
D) 3.2 × 10-10
E) 8.1 × 10-12
18) Calculate the maximum concentration (in M) of magnesium ions (Mg+2) in a solution that contains 0.025 M of CO32-. The Ksp of MgCO3 is 3.5 × 10-8.
A) 1.8 × 10-5
B) 1.4 × 10-6
C) 2.8 × 10-6
D) 3.2 × 10-10
E) 8.1 × 10-12
19) What is the solubility (in M) of PbCl2 in a 0.15 M solution of HCl? The Ksp of PbCl2 is 1.6 × 10-5.
A) 2.0 × 10-3
B) 1.1 × 10-4
C) 1.8 × 10-4
D) 7.1 × 10-4
E) 1.6 × 10-5
20) The Ksp for Zn(OH)2 is 5.0 × 10-17. Determine the molar solubility of Zn(OH)2 in a buffer solution with a pH of 11.5.
A) 5.0 × 106
B) 1.2 × 10-12
C) 1.6 × 10-14
D) 5.0 × 10-12
E) 5.0 × 10-17
17.3 Algorithmic Questions
1) Calculate the pH of a solution that is 0.295 M in sodium formate (NaHCO2) and 0.205 M in formic acid (HCO2H). The Ka of formic acid is 1.77 × 10-4.
A) 3.910
B) 3.587
C) 13.84
D) 10.10
E) 4.963
2) Calculate the percent ionization of formic acid (HCO2H) in a solution that is 0.311 M in formic acid and 0.189 M in sodium formate (NaHCO2). The Ka of formic acid is 1.77 × 10-4.
A) 37.8
B) 0.0937
C) 11.3
D) 1.06 × 10-3
E) 3.529
3) Calculate the percent ionization of formic acid (HCO2H) in a solution that is 0.219 M in formic acid. The Ka of formic acid is 1.77 × 10-4.
A) 3.94 × 10-5
B) 0.0180
C) 2.84
D) 0.280
E) 12.2
4) Calculate the pH of a solution that is 0.210 M in nitrous acid (HNO2) and 0.290 M in potassium nitrite (KNO2). The acid dissociation constant of nitrous acid is 4.50 × 10-4.
A) 3.487
B) 3.210
C) 13.86
D) 10.51
E) 4.562
5) Calculate the percent ionization of nitrous acid in a solution that is 0.222 M in nitrous acid (HNO2) and 0.278 M in potassium nitrite (KNO2). The acid dissociation constant of nitrous acid is 4.50 × 10-4.
A) 55.6
B) 0.162
C) 15.5
D) 2.78 × 10-3
E) 3.448
6) Calculate the percent ionization of nitrous acid in a solution that is 0.249 M in nitrous acid. The acid dissociation constant of nitrous acid is 4.50 × 10-4.
A) 1.12 × 10-4
B) 0.0450
C) 4.25
D) 0.342
E) 5.53
7) What is the pH of a buffer solution that is 0.211 M in lactic acid and 0.111 M in sodium lactate? The Ka of lactic acid is 1.4 × 10-4.
A) 14.28
B) 10.43
C) 5.48
D) 3.57
E) 4.13
8) What is the pH of a buffer solution that is 0.255 M in hypochlorous acid (HClO) and 0.333 M in sodium hypochlorite? The Ka of hypochlorous acid is 3.8 × 10-8.
A) 13.88
B) 6.46
C) 8.49
D) 7.30
E) 7.54
9) A solution is prepared by dissolving 0.23 mol of hydrofluoric acid and 0.27 mol of sodium fluoride 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 hydrofluoric acid is 1.36 × 10-3.
A) H2O
B) H3O+
C) fluoride ion
D) hydrofluoric acid
E) This is a buffer solution: the pH does not change upon addition of acid or base.
10) A solution is prepared by dissolving 0.23 mol of hydrazoic acid and 0.27 mol of sodium azide 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 hydrazoic acid is 1.9 × 10-5.
A) H2O
B) H3O+
C) azide
D) hydrazoic acid
E) This is a buffer solution: the pH does not change upon addition of acid or base.
11) The pH of a solution that contains 0.818 M acetic acid (Ka = 1.76 × 10-5) and 0.182 M sodium acetate is __________.
A) 4.102
B) 5.407
C) 8.593
D) 8.370
E) 9.898
12) Consider a solution containing 0.100 M fluoride ions and 0.126 M hydrogen fluoride. The concentration of fluoride ions after the addition of 4.00 mL of 0.0100 M HCl to 25.0 mL of this solution is __________ M.
A) 0.0862
B) 0.0876
C) 0.0980
D) 0.0848
E) 0.00253
13) Consider a solution containing 0.100 M fluoride ions and 0.126 M hydrogen fluoride. The concentration of hydrogen fluoride after addition of 8.00 mL of 0.0100 M HCl to 25.0 mL of this solution is __________ M.
A) 0.0979
B) 0.0930
C) 0.129
D) 0.123
E) 0.00976
14) The Ka of acetic acid is 1.76 × 10-5. The pH of a buffer prepared by combining 45.0 mL of 1.00 M potassium acetate and 50.0 mL of 1.00 M acetic acid is __________.
A) 1.705
B) 0.851
C) 3.406
D) 4.709
E) 2.383
15) The Kb of ammonia is 1.76 × 10-5. The pH of a buffer prepared by combining 50.0 mL of 1.00 M ammonia and 50.0 mL of 1.00 M ammonium nitrate is __________.
A) 4.632
B) 9.246
C) 4.742
D) 9.372
E) none of the above
16) Calculate the pH of a solution prepared by dissolving 0.270 mol of formic acid (HCO2H) and 0.230 mol of sodium formate (NaCO2H) in water sufficient to yield 1.00 L of solution. The Ka of formic acid is 1.77 × 10-4.
A) 2.099
B) 10.318
C) 3.682
D) 2.307
E) 3.952
17) Calculate the pH of a solution prepared by dissolving 0.850 mol of NH3 and 0.350 mol of NH4Cl in water sufficient to yield 1.00 L of solution. The Kb of ammonia is 1.77 × 10-5.
A) 5.137
B) 4.367
C) 9.633
D) 8.781
E) 8.863
18) Calculate the pH of a solution prepared by dissolving 0.350 mol of benzoic acid (C7H5O2H) and 0.250 mol of sodium benzoate (NaC7H5O2) in water sufficient to yield 1.00 L of solution. The Ka of benzoic acid is 6.50 × 10-5.
A) 4.333
B) 4.041
C) 9.959
D) 9.667
E) 5.190
19) How many milliliters of 0.0850 M NaOH are required to titrate 25.0 mL of 0.0720 M HBr to the equivalence point?
A) 21.2
B) 0.245
C) 3.92
D) 0.153
E) 29.5
20) A 25.0 mL sample of 0.150 M hydrazoic acid is titrated with a 0.150 M NaOH solution. What is the pH at the equivalence point? The Ka of hydrazoic acid is 4.50 × 10-4.
A) 11.72
B) 9.28
C) 4.72
D) 7.00
E) 8.80
21) A 25.0-mL sample of 0.150 M butanoic acid is titrated with a 0.150 M NaOH solution. What is the pH before any base is added? The Ka of butanoic acid is 1.5 × 10-5.
A) 2.83
B) 1.5 × 10-3
C) 4.82
D) 4.00
E) 1.0 × 104
22) A 25.0 mL sample of 0.150 M hypochlorous acid is titrated with a 0.150 M NaOH solution. What is the pH after 26.0 mL of base is added? The Ka of hypochlorous acid is 3.0 × 10-8.
A) 2.54
B) 11.47
C) 7.00
D) 7.51
E) 7.54
23) How many milliliters of 0.120 M NaOH are required to titrate 50.0 mL of 0.0998 M butanoic acid to the equivalence point? The Ka of butanoic acid is 1.5 × 10-5.
A) 4.90
B) 50.0
C) 41.6
D) 60.1
E) 4.65
24) A 25.0-mL sample of 0.150 M hydrazoic acid is titrated with a 0.150 M NaOH solution. What is the pH after 13.3 mL of base is added? The Ka of hydrazoic acid is 1.9 × 10-5.
A) 4.45
B) 1.34
C) 3.03
D) 4.78
E) 4.66
25) A 25.0 mL sample of 0.723 M HClO4 is titrated with a 0.273 M KOH solution. The H3O+ concentration after the addition of 60.0 mL of KOH is __________ M.
A) 0.0181
B) 0.430
C) 0.0200
D) 0.273
E) none of the above
26) A 25.0 mL sample of an acetic acid solution is titrated with a 0.175 M NaOH solution. The equivalence point is reached when 26.6 mL of the base is added. The concentration of acetic acid in the sample was __________ M.
A) 0.365
B) 0.175
C) 0.119
D) 0.186
E) none of the above
27) A 25.0 mL sample of an HCl solution is titrated with a 0.139 M NaOH solution. The equivalence point is reached with 25.3 mL of base. The concentration of HCl is __________ M.
A) 11.7
B) 0.00352
C) 0.141
D) 0.0352
E) 0.139
28) The pH of a solution prepared by mixing 45.0 mL of 0.183 M KOH and 25.0 mL of 0.145 M HCl is __________.
A) 1.314
B) 1.181
C) 0.00824
D) 12.819
E) 12.923
29) The pH of a solution prepared by mixing 55.0 mL of 0.183 M KOH and 30.0 mL of 0.145 M HC2H3O2 is __________.
A) 9.97
B) 7.74
C) 1.172
D) 12.828
E) none of the above
30) What is the molar solubility of silver chloride (AgCl) in water? The solubility-product constant for AgCl is 1.8 × 10-10 at 25°C.
A) 9.0 × 10-11
B) 3.6 × 10-10
C) 9.74
D) 1.9 × 10-5
E) 1.3 × 10-5
31) What is the molar solubility of silver sulfate (Ag2SO4) in water? The solubility-product constant for Ag2SO4 is 1.5 × 10-5 at 25°C.
A) 1.9 × 10-3
B) 2.5 × 10-2
C) 5.5 × 10-3
D) 1.6 × 10-2
E) 5.0 × 10-6
32) In which aqueous system is Pbl2 least soluble?
A) H2O
B) 0.5 M HI
C) 0.2 M HI
D) 1.0 M HNO3
E) 0.8 M KI
33) A solution of NaF is added dropwise to a solution that is 0.0144 M in Ba2+. When the concentration of F- exceeds __________ M, BaF2 will precipitate. Neglect volume changes. For BaF2,
Ksp = 1.7 × 10-6.
A) 5.9 × 10-5
B) 1.1 × 10-2
C) 2.4 × 10-8
D) 2.7 × 10-3
E) 1.2 × 10-4
17.4 Short Answer Questions
1) Calculate the pH of a buffer that contains 0.270 M hydrofluoric acid (HF) and 0.180 M cesium fluoride (CsF). The Ka of hydrofluoric acid is 6.80 × 10-4.
2) Calculate the pH of a buffer solution that contains 0.820 grams of sodium acetate and 0.010 moles of acetic acid in 100 ml of water. The Ka of acetic acid is 1.77 × 10-5.
3) Suppose you have just added 100.0 ml of a solution containing 0.5000 moles of acetic acid per liter to 400.0 ml of 0.5000 M NaOH. What is the final pH? The Ka of acetic acid is 1.77 × 10-5.
4) Suppose you have just added 200.0 ml of a solution containing 0.5000 moles of acetic acid per liter to 100.0 ml of 0.5000 M NaOH. What is the final pH? The Ka of acetic acid is 1.77 × 10-5.
5) 200.0 ml of a solution containing 0.5000 moles of acetic acid per liter is added to 200.0 ml of 0.5000 M NaOH. What is the final pH? The Ka of acetic acid is 1.77 × 10-5.
6) In general, the solubility of a slightly soluble salt is __________ by the presence of a second solute that furnishes a common ion.
7) Although CaCO3 has a relatively small solubility product, it is quite soluble in the presence of __________.
8) An assembly of a metal ion and the Lewis bases bonded to it is called a __________.
9) Metal oxides and hydroxides that are relatively insoluble in neutral water, but are soluble in both strongly acidic and strongly basic solutions are said to be __________.
10) __________ analysis determines only the presence or absence of a particular metal ion, whereas __________ analysis determines how much of a given substance is present.
17.5 True/False Questions
1) The extent of ionization of a weak electrolyte is increased by adding to the solution a strong electrolyte that has an ion in common with the weak electrolyte.
2) For any buffer system, the buffer capacity depends on the amount of acid and base from which the buffer is made.
3) The solubility product of a compound is numerically equal to the product of the concentration of the ions involved in the equilibrium, each multiplied by its coefficient in the equilibrium reaction.
4) The solubility of a slightly soluble salt is decreased by the presence of a second solute that provides a common ion to the system.
5) The solubility of slightly soluble salts containing basic anions is proportional to the pH of the solution.
Answer:
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