Questão 1
Questão
Which one of the following pairs cannot be mixed together to form a buffer solution?
Responda
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A) HONH2, HONH3Cl
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B) NaCl, HCl
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C) RbOH, HF
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D) KOH, HNO2
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E) H2SO3, KHSO3
Questão 2
Questão
Which one of the following pairs cannot be mixed together to form a buffer solution?
Questão 3
Questão
A solution containing which one of the following pairs of substances will be a buffer solution?
Responda
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A) NaI, HI
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B) KBr, HBr
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C) RbCl, HCl
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D) CsF, HF
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E) none of the above
Questão 4
Questão
What change will be caused by addition of a small amount of HCl to a solution containing fluoride ions and hydrogen fluoride?
Responda
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A) The concentration of hydronium ions will increase significantly.
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B) The concentration of fluoride ions will increase as will the concentration of hydronium ions.
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C) The concentration of hydrogen fluoride will decrease and the concentration of fluoride ions will increase.
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D) The concentration of fluoride ion will decrease and the concentration of hydrogen fluoride will increase.
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E) The fluoride ions will precipitate out of solution as its acid salt.
Questão 5
Questão
In a solution, when the concentrations of a weak acid and its conjugate base are equal,
Responda
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A) the system is not at equilibrium.
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B) the buffering capacity is significantly decreased.
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C) the -log of the [H+] and the -log of the Ka are equal.
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D) all of the above are true.
Questão 6
Questão
Of the following solutions, which has the greatest buffering capacity?
Responda
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A) 0.521 M HC2H3O2 and 0.217 M NaC2H3O2
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B) 0.821 M HC2H3O2 and 0.713 M NaC2H3O2
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C) 0.365M HC2H3O2 and 0.497 M NaC2H3O2
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D) 0.121 M HC2H3O2 and 0.116 M NaC2H3O2
Questão 7
Questão
) Of the following solutions, which has the greatest buffering capacity?
Responda
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A) 0.543 M NH3 and 0.555 M NH4Cl
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B) 0.087 M NH3 and 0.088 M NH4Cl
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C) 0.234 M NH3 and 0.100 M NH4Cl
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D) 0.100 M NH3 and 0.455 M NH4Cl
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E) They are all buffer solutions and would all have the same capacity.
Questão 8
Questão
The addition of hydrofluoric acid and __________ to water produces a buffer solution.
Responda
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A) HCl
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B) NaNO3
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C) NaF
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D) NaCl
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E) NaBr
Questão 9
Questão
The addition of sodium hydroxide and __________ to water produces a buffer solution.
Responda
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A) HCl
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B) NaC2H3O2
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C) NaF
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D) NH3
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E) none of the above
Questão 10
Questão
Which of the following could be added to a solution of potassium fluoride to prepare a buffer?
Responda
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A) sodium hydroxide
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B) potassium acetate
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C) hydrochloric acid
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D) sodium fluoride
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E) ammonia
Questão 11
Questão
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 __________.
Responda
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A) a strong acid
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B) a strong base
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C) a weak acid
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D) a weak base
Questão 12
Questão
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.
Responda
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A) 25.0
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B) 0.0600
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C) 0.240
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D) 0.120
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E) 0.100
Questão 13
Questão
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?
Responda
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A) methyl red
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B) bromthymol blue
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C) thymol blue
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D) phenolpthalein
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E) bromocresol purple
Questão 14
Questão
Which compound listed below has the greatest molar solubility in water?
Responda
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A) CdCO3
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B) Cd(OH)2
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C) AgI
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D) CaF2
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E) ZnCO3
Questão 15
Questão
The molar solubility of __________ is not affected by the pH of the solution.
Responda
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A) Na3PO4
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B) NaF
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C) KNO3
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D) ACl3
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E) MnS
Questão 16
Questão
In which of the following aqueous solutions would you expect AgCl to have the lowest solubility?
Responda
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A) pure water
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B) 0.020 M BaCl2
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C) 0.015 NaCl
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D) 0.020 AgNO3
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E) 0.020 KCl
Questão 17
Questão
In which one of the following solutions is silver chloride the most soluble?
Responda
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A) 0.181 M HCl
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B) 0.0176 M NH3
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C) 0.744 M LiNO3
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D) pure water
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E) 0.181 M NaCl
Questão 18
Questão
Which below best describe(s) the behavior of an amphoteric hydroxide in water?
Responda
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A) With conc. aq. NaOH, its suspension dissolves.
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B) With conc. aq. HCl, its suspension dissolves.
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C) With conc. aq. NaOH, its clear solution forms a precipitate.
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D) With conc. aq. HCl, its clear solution forms a precipitate.
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E) With both conc. aq. NaOH and conc. aq. HCl, its suspension dissolves.
Questão 19
Questão
A result of the common-ion effect is __________.
Responda
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A) that some ions, such as Na+ (aq), frequently appear in solutions but do not participate in solubility equilibria
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B) that common ions, such as Na+ (aq), don't affect equilibrium constants
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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
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D) that ions such as K+ and Na+ are common ions, so that their values in equilibrium constant expressions are always 1.00
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E) that common ions precipitate all counter-ions
Questão 20
Questão
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 __________.
Responda
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A) 1.705
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B) 0.851
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C) 3.406
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D) 4.201
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E) 2.383
Questão 21
Questão
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.
Responda
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A) 2.516
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B) 3.892
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C) 4.502
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D) 10.158
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E) 5.056
Questão 22
Questão
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.)
Responda
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A) 1.66
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B) 2.86
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C) 10.28
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D) 11.14
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E) 10.61
Questão 23
Questão
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.
Responda
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A) 0.0333
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B) 1 × 10-7
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C) 0.7
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D) 3 × 10-13
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E) 4 × 10-2
Questão 24
Questão
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 __________.
Responda
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A) 6.29
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B) 7.00
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C) 8.11
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D) 5.78
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E) 0.00
Questão 25
Questão
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 __________.
Responda
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A) 6.29
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B) 4.11
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C) 1.14
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D) 5.78
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E) 1.34
Questão 26
Questão
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 __________.
Responda
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A) 13.29
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B) 7.00
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C) 8.11
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D) 11.00
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E) none of the above
Questão 27
Questão
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.
Responda
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A) 0.234
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B) 0.469
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C) 0.150
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D) 0.300
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E) 0.938
Questão 28
Questão
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.
Responda
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A) 3.8 × 10-4
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B) 3.0 × 10-3
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C) 1.5 × 10-3
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D) 3.5 × 10-9
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E) 1.4 × 10-8
Questão 29
Questão
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.
Responda
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A) 37.8
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B) 0.0937
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C) 11.3
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D) 1.06 × 10-3
-
E) 3.529
Questão 30
Questão
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.
Questão 31
Questão
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.
Questão 32
Questão
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.
Responda
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A) 0.0862
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B) 0.0876
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C) 0.0980
-
D) 0.0848
-
E) 0.00253
Questão 33
Questão
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 __________.
Responda
-
A) 1.705
-
B) 0.851
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C) 3.406
-
D) 4.709
-
E) 2.383
Questão 34
Questão
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 __________.
Responda
-
A) 4.632
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B) 9.246
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C) 4.742
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D) 9.372
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E) none of the above
Questão 35
Questão
How many milliliters of 0.0850 M NaOH are required to titrate 25.0 mL of 0.0720 M HBr to the equivalence point?
Responda
-
A) 21.2
-
B) 0.245
-
C) 3.92
-
D) 0.153
-
E) 29.5
Questão 36
Questão
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.
Responda
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A) 11.72
-
B) 9.28
-
C) 4.72
-
D) 7.00
-
E) 8.80
Questão 37
Questão
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.
Responda
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A) 2.83
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B) 1.5 × 10-3
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C) 4.82
-
D) 4.00
-
E) 1.0 × 104
Questão 38
Questão
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.
Responda
-
A) 2.54
-
B) 11.47
-
C) 7.00
-
D) 7.51
-
E) 7.54
Questão 39
Questão
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.
Responda
-
A) 4.45
-
B) 1.34
-
C) 3.03
-
D) 4.78
-
E) 4.66
Questão 40
Questão
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.
Responda
-
A) 0.0181
-
B) 0.430
-
C) 0.0200
-
D) 0.273
-
E) none of the above
Questão 41
Questão
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 __________.
Responda
-
A) 1.314
-
B) 1.181
-
C) 0.00824
-
D) 12.819
-
E) 12.923
Questão 42
Questão
In which aqueous system is Pbl2 least soluble?
Responda
-
A) H2O
-
B) 0.5 M HI
-
C) 0.2 M HI
-
D) 1.0 M HNO3
-
E) 0.8 M KI
Questão 43
Questão
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.
Responda
-
A) 9.123
-
B) 4.877
-
C) 0.5229
-
D) 13.48
Questão 44
Questão
An assembly of a metal ion and the Lewis bases bonded to it is called a __________.
Responda
-
A) Complex Ion
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B) Lewis Structure
-
C) Soluble compound
Questão 45
Questão
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 __________.
Responda
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A) amphiprotic
-
B) amphoteric
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C) amphiphilic
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D) amphipathic