Chapter 15/14?- Additional aspects of aqueous equilibria

Question 1 of 45

1

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

Select one of the following:

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

Explanation

Question 2 of 45

1

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

Select one of the following:

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

Explanation

Question 3 of 45

1

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

Select one of the following:

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

Explanation

Question 4 of 45

1

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

Select one of the following:

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.

Explanation

Question 5 of 45

1

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

Select one of the following:

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.

Explanation

Question 6 of 45

1

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

Select one of the following:

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

Explanation

Question 7 of 45

1

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

Select one of the following:

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.

Explanation

Question 8 of 45

1

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

Select one of the following:

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

Explanation

Question 9 of 45

1

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

Select one of the following:

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

Explanation

Question 10 of 45

1

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

Select one of the following:

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

Explanation

Question 11 of 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 __________.

Select one of the following:

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

Explanation

Question 12 of 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.

Select one of the following:

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

Explanation

Question 13 of 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?

Select one of the following:

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

Explanation

Question 14 of 45

1

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

Select one of the following:

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

Explanation

Question 15 of 45

1

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

Select one of the following:

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

Explanation

Question 16 of 45

1

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

Select one of the following:

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

Explanation

Question 17 of 45

1

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

Select one of the following:

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

Explanation

Question 18 of 45

1

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

Select one of the following:

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.

Explanation

Question 19 of 45

1

A result of the common-ion effect is __________.

Select one of the following:

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

Explanation

Question 20 of 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 __________.

Select one of the following:

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

Explanation

Question 21 of 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.

Select one of the following:

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

Explanation

Question 22 of 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.)

Select one of the following:

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

Explanation

Question 23 of 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.

Select one of the following:

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

Explanation

Question 24 of 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 __________.

Select one of the following:

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

Explanation

Question 25 of 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 __________.

Select one of the following:

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

Explanation

Question 26 of 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 __________.

Select one of the following:

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

Explanation

Question 27 of 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.

Select one of the following:

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

Explanation

Question 28 of 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.

Select one of the following:

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

Explanation

Question 29 of 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.

Select one of the following:

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

Explanation

Question 30 of 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.

Select one of the following:

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.

Explanation

Question 31 of 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.

Select one of the following:

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.

Explanation

Question 32 of 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.

Select one of the following:

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

Explanation

Question 33 of 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 __________.

Select one of the following:

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

Explanation

Question 34 of 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 __________.

Select one of the following:

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

Explanation

Question 35 of 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?

Select one of the following:

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

Explanation

Question 36 of 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.

Select one of the following:

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

Explanation

Question 37 of 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.

Select one of the following:

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

Explanation

Question 38 of 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.

Select one of the following:

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

Explanation

Question 39 of 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.

Select one of the following:

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

Explanation

Question 40 of 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.

Select one of the following:

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

Explanation

Question 41 of 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 __________.

Select one of the following:

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

Explanation

Question 42 of 45

1

In which aqueous system is Pbl2 least soluble?

Select one of the following:

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

Explanation

Question 43 of 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.

Select one of the following:

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

Explanation

Question 44 of 45

1

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

Select one of the following:

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

Explanation

Question 45 of 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 __________.

Select one of the following:

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

	Created by Dawn G over 9 years ago

Originally chapter 17

Chapter 15/14?- Additional aspects of aqueous equilibria

Question 1 of 45

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

Select one of the following:

Explanation

Question 2 of 45

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

Select one of the following:

Explanation

Question 3 of 45

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

Select one of the following:

Explanation

Question 4 of 45

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

Select one of the following:

Explanation

Question 5 of 45

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

Select one of the following:

Explanation

Question 6 of 45

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

Select one of the following:

Explanation

Question 7 of 45

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

Select one of the following:

Explanation

Question 8 of 45

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

Select one of the following:

Explanation

Question 9 of 45

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

Select one of the following:

Explanation

Question 10 of 45

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

Select one of the following:

Explanation

Question 11 of 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 __________.

Select one of the following:

Explanation

Question 12 of 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.

Select one of the following:

Explanation

Question 13 of 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?

Select one of the following:

Explanation

Question 14 of 45

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

Select one of the following:

Explanation

Question 15 of 45

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

Select one of the following:

Explanation

Question 16 of 45

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

Select one of the following:

Explanation

Question 17 of 45

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

Select one of the following:

Explanation

Question 18 of 45

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

Select one of the following:

Explanation

Question 19 of 45

A result of the common-ion effect is __________.

Select one of the following:

Explanation

Question 20 of 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 __________.