Chapter 15/14?- Additional aspects of aqueous equilibria

Questão 1 de 45

1

Which one of the following pairs cannot be mixed together to form a buffer solution?

Selecione uma das seguintes:

A) HONH2, HONH3Cl
B) NaCl, HCl
C) RbOH, HF
D) KOH, HNO2
E) H2SO3, KHSO3

Explicação

Questão 2 de 45

1

Which one of the following pairs cannot be mixed together to form a buffer solution?

Selecione uma das seguintes:

A) NH3, NH4Cl
B) NaC2H3O2, HCl (C2H3O2- = acetate)
C) RbOH, HBr
D) KOH, HF
E) H3PO4, KH2PO4

Explicação

Questão 3 de 45

1

A solution containing which one of the following pairs of substances will be a buffer solution?

Selecione uma das seguintes:

A) NaI, HI
B) KBr, HBr
C) RbCl, HCl
D) CsF, HF
E) none of the above

Explicação

Questão 4 de 45

1

What change will be caused by addition of a small amount of HCl to a solution containing fluoride ions and hydrogen fluoride?

Selecione uma das seguintes:

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.

Explicação

Questão 5 de 45

1

In a solution, when the concentrations of a weak acid and its conjugate base are equal,

Selecione uma das seguintes:

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.

Explicação

Questão 6 de 45

1

Of the following solutions, which has the greatest buffering capacity?

Selecione uma das seguintes:

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

Explicação

Questão 7 de 45

1

) Of the following solutions, which has the greatest buffering capacity?

Selecione uma das seguintes:

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.

Explicação

Questão 8 de 45

1

The addition of hydrofluoric acid and __________ to water produces a buffer solution.

Selecione uma das seguintes:

A) HCl
B) NaNO3
C) NaF
D) NaCl
E) NaBr

Explicação

Questão 9 de 45

1

The addition of sodium hydroxide and __________ to water produces a buffer solution.

Selecione uma das seguintes:

A) HCl
B) NaC2H3O2
C) NaF
D) NH3
E) none of the above

Explicação

Questão 10 de 45

1

Which of the following could be added to a solution of potassium fluoride to prepare a buffer?

Selecione uma das seguintes:

A) sodium hydroxide
B) potassium acetate
C) hydrochloric acid
D) sodium fluoride
E) ammonia

Explicação

Questão 11 de 45

1

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 __________.

Selecione uma das seguintes:

A) a strong acid
B) a strong base
C) a weak acid
D) a weak base

Explicação

Questão 12 de 45

1

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.

Selecione uma das seguintes:

A) 25.0
B) 0.0600
C) 0.240
D) 0.120
E) 0.100

Explicação

Questão 13 de 45

1

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?

Selecione uma das seguintes:

A) methyl red
B) bromthymol blue
C) thymol blue
D) phenolpthalein
E) bromocresol purple

Explicação

Questão 14 de 45

1

Which compound listed below has the greatest molar solubility in water?

Selecione uma das seguintes:

A) CdCO3
B) Cd(OH)2
C) AgI
D) CaF2
E) ZnCO3

Explicação

Questão 15 de 45

1

The molar solubility of __________ is not affected by the pH of the solution.

Selecione uma das seguintes:

A) Na3PO4
B) NaF
C) KNO3
D) ACl3
E) MnS

Explicação

Questão 16 de 45

1

In which of the following aqueous solutions would you expect AgCl to have the lowest solubility?

Selecione uma das seguintes:

A) pure water
B) 0.020 M BaCl2
C) 0.015 NaCl
D) 0.020 AgNO3
E) 0.020 KCl

Explicação

Questão 17 de 45

1

In which one of the following solutions is silver chloride the most soluble?

Selecione uma das seguintes:

A) 0.181 M HCl
B) 0.0176 M NH3
C) 0.744 M LiNO3
D) pure water
E) 0.181 M NaCl

Explicação

Questão 18 de 45

1

Which below best describe(s) the behavior of an amphoteric hydroxide in water?

Selecione uma das seguintes:

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.

Explicação

Questão 19 de 45

1

A result of the common-ion effect is __________.

Selecione uma das seguintes:

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

Explicação

Questão 20 de 45

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 __________.

Selecione uma das seguintes:

A) 1.705
B) 0.851
C) 3.406
D) 4.201
E) 2.383

Explicação

Questão 21 de 45

1

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.

Selecione uma das seguintes:

A) 2.516
B) 3.892
C) 4.502
D) 10.158
E) 5.056

Explicação

Questão 22 de 45

1

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.)

Selecione uma das seguintes:

A) 1.66
B) 2.86
C) 10.28
D) 11.14
E) 10.61

Explicação

Questão 23 de 45

1

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.

Selecione uma das seguintes:

A) 0.0333
B) 1 × 10-7
C) 0.7
D) 3 × 10-13
E) 4 × 10-2

Explicação

Questão 24 de 45

1

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 __________.

Selecione uma das seguintes:

A) 6.29
B) 7.00
C) 8.11
D) 5.78
E) 0.00

Explicação

Questão 25 de 45

1

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 __________.

Selecione uma das seguintes:

A) 6.29
B) 4.11
C) 1.14
D) 5.78
E) 1.34

Explicação

Questão 26 de 45

1

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 __________.

Selecione uma das seguintes:

A) 13.29
B) 7.00
C) 8.11
D) 11.00
E) none of the above

Explicação

Questão 27 de 45

1

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.

Selecione uma das seguintes:

A) 0.234
B) 0.469
C) 0.150
D) 0.300
E) 0.938

Explicação

Questão 28 de 45

1

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.

Selecione uma das seguintes:

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

Explicação

Questão 29 de 45

1

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.

Selecione uma das seguintes:

A) 37.8
B) 0.0937
C) 11.3
D) 1.06 × 10-3
E) 3.529

Explicação

Questão 30 de 45

1

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.

Selecione uma das seguintes:

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.

Explicação

Questão 31 de 45

1

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.

Selecione uma das seguintes:

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.

Explicação

Questão 32 de 45

1

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.

Selecione uma das seguintes:

A) 0.0862
B) 0.0876
C) 0.0980
D) 0.0848
E) 0.00253

Explicação

Questão 33 de 45

1

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 __________.

Selecione uma das seguintes:

A) 1.705
B) 0.851
C) 3.406
D) 4.709
E) 2.383

Explicação

Questão 34 de 45

1

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 __________.

Selecione uma das seguintes:

A) 4.632
B) 9.246
C) 4.742
D) 9.372
E) none of the above

Explicação

Questão 35 de 45

1

How many milliliters of 0.0850 M NaOH are required to titrate 25.0 mL of 0.0720 M HBr to the equivalence point?

Selecione uma das seguintes:

A) 21.2
B) 0.245
C) 3.92
D) 0.153
E) 29.5

Explicação

Questão 36 de 45

1

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.

Selecione uma das seguintes:

A) 11.72
B) 9.28
C) 4.72
D) 7.00
E) 8.80

Explicação

Questão 37 de 45

1

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.

Selecione uma das seguintes:

A) 2.83
B) 1.5 × 10-3
C) 4.82
D) 4.00
E) 1.0 × 104

Explicação

Questão 38 de 45

1

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.

Selecione uma das seguintes:

A) 2.54
B) 11.47
C) 7.00
D) 7.51
E) 7.54

Explicação

Questão 39 de 45

1

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.

Selecione uma das seguintes:

A) 4.45
B) 1.34
C) 3.03
D) 4.78
E) 4.66

Explicação

Questão 40 de 45

1

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.

Selecione uma das seguintes:

A) 0.0181
B) 0.430
C) 0.0200
D) 0.273
E) none of the above

Explicação

Questão 41 de 45

1

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 __________.

Selecione uma das seguintes:

A) 1.314
B) 1.181
C) 0.00824
D) 12.819
E) 12.923

Explicação

Questão 42 de 45

1

In which aqueous system is Pbl2 least soluble?

Selecione uma das seguintes:

A) H2O
B) 0.5 M HI
C) 0.2 M HI
D) 1.0 M HNO3
E) 0.8 M KI

Explicação

Questão 43 de 45

1

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.

Selecione uma das seguintes:

A) 9.123
B) 4.877
C) 0.5229
D) 13.48

Explicação

Questão 44 de 45

1

An assembly of a metal ion and the Lewis bases bonded to it is called a __________.

Selecione uma das seguintes:

A) Complex Ion
B) Lewis Structure
C) Soluble compound

Explicação

Questão 45 de 45

1

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 __________.

Selecione uma das seguintes:

A) amphiprotic
B) amphoteric
C) amphiphilic
D) amphipathic

	Criado por Dawn G quase 10 anos atrás

Originally chapter 17

Chapter 15/14?- Additional aspects of aqueous equilibria

Questão 1 de 45

Which one of the following pairs cannot be mixed together to form a buffer solution?

Selecione uma das seguintes:

Explicação

Questão 2 de 45

Which one of the following pairs cannot be mixed together to form a buffer solution?

Selecione uma das seguintes:

Explicação

Questão 3 de 45

A solution containing which one of the following pairs of substances will be a buffer solution?

Selecione uma das seguintes:

Explicação

Questão 4 de 45

What change will be caused by addition of a small amount of HCl to a solution containing fluoride ions and hydrogen fluoride?

Selecione uma das seguintes:

Explicação

Questão 5 de 45

In a solution, when the concentrations of a weak acid and its conjugate base are equal,

Selecione uma das seguintes:

Explicação

Questão 6 de 45

Of the following solutions, which has the greatest buffering capacity?

Selecione uma das seguintes:

Explicação

Questão 7 de 45

) Of the following solutions, which has the greatest buffering capacity?

Selecione uma das seguintes:

Explicação

Questão 8 de 45

The addition of hydrofluoric acid and __________ to water produces a buffer solution.

Selecione uma das seguintes:

Explicação

Questão 9 de 45

The addition of sodium hydroxide and __________ to water produces a buffer solution.

Selecione uma das seguintes:

Explicação

Questão 10 de 45

Which of the following could be added to a solution of potassium fluoride to prepare a buffer?

Selecione uma das seguintes:

Explicação

Questão 11 de 45

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 __________.

Selecione uma das seguintes:

Explicação

Questão 12 de 45

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.

Selecione uma das seguintes:

Explicação

Questão 13 de 45

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?

Selecione uma das seguintes:

Explicação

Questão 14 de 45

Which compound listed below has the greatest molar solubility in water?

Selecione uma das seguintes:

Explicação

Questão 15 de 45

The molar solubility of __________ is not affected by the pH of the solution.

Selecione uma das seguintes:

Explicação

Questão 16 de 45

In which of the following aqueous solutions would you expect AgCl to have the lowest solubility?

Selecione uma das seguintes:

Explicação

Questão 17 de 45

In which one of the following solutions is silver chloride the most soluble?

Selecione uma das seguintes:

Explicação

Questão 18 de 45

Which below best describe(s) the behavior of an amphoteric hydroxide in water?

Selecione uma das seguintes:

Explicação

Questão 19 de 45

A result of the common-ion effect is __________.

Selecione uma das seguintes:

Explicação

Questão 20 de 45

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 __________.