Question 1

A cleaning solution has a pOH of 4.0. What is the pH and hydronium ion concentration of this solution?

Accepted Answer

pH = 10; [

Question 2

The base ionization constant Kb describes which of the following reactions for a weak base, B, in aqueous solution?

Accepted Answer

A)  B + H+     BH+ 
B)  B + H3O+   BH+ + H2O 
C)  B + H2O   BH+ + OH- 
D)  B + OH-   BH- + O2- 
E)  BH+ + OH-   B + H2O 
A)  B + H+     BH+ 
B)  B + H3O+   BH+ + H2O 
C)  B + H2O   BH+ + OH- 
D)  B + OH-   BH- + O2- 
E)  BH+ + OH-   B + H2O

Question 3

Acid-base indicators change color __________

Accepted Answer

A)  exactly when pH = pKa of the indicator. 
B)  generally over a range of 1 or 2 pH units. 
C)  at pH = 7. 
D)  always between a pH of 6 and 8. 
E)  at the midpoint of a titration. 
A)  exactly when pH = pKa of the indicator. 
B)  generally over a range of 1 or 2 pH units. 
C)  at pH = 7. 
D)  always between a pH of 6 and 8. 
E)  at the midpoint of a titration.

Question 4

A solution that contains a weak acid and its conjugate base in roughly equal concentrations is __________

Accepted Answer

A)  neither acidic or basic. 
B)  a half-acid solution. 
C)  a buffer. 
D)  a heterogeneous mixture. 
E)  neutral. 
A)  neither acidic or basic. 
B)  a half-acid solution. 
C)  a buffer. 
D)  a heterogeneous mixture. 
E)  neutral.

Question 5

A phosphate buffer solution (25.00 mL sample) used for a growth medium was titrated with 0.1000 M hydrochloric acid. The components of the buffer were sodium monohydrogenphosphate and sodium dihydrogenphosphate. The first endpoint occurred at a volume of 10.32 mL; the second occurred after an additional 18.62 mL was added (or total volume = 28.94 mL). What was the approximate ratio of HPO42- to H2PO4- in the buffer?

Accepted Answer

A)  1:1 
B)  4:5 
C)  5:3 
D)  5:4 
E)  3:5 
A)  1:1 
B)  4:5 
C)  5:3 
D)  5:4 
E)  3:5

Question 6

A solution with a pOH of 6.92 has an [OH-] concentration of __________

Accepted Answer

A)  1.20 F1F1F1S1F1F1F10 10-7 M. 
B)  9.2 F1F1F1S1F1F1F10 10-6 M. 
C)  6.8 F1F1F1S1F1F1F10 10-6 M. 
D)  7.08 M. 
E)  6.92 M. 
A)  1.20 F1F1F1S1F1F1F10 10-7 M. 
B)  9.2 F1F1F1S1F1F1F10 10-6 M. 
C)  6.8 F1F1F1S1F1F1F10 10-6 M. 
D)  7.08 M. 
E)  6.92 M.

Question 7

When an acetic acid solution is titrated with sodium hydroxide, the slope of the titration curve (pH vs volume of NaOH added) increases when sodium hydroxide is first added. This change shows that __________.

Accepted Answer

A)  nothing is happening during this part of the titration. 
B)  the reaction is very slow during this part of the titration. 
C)  a more concentrated solution of NaOH needs to be present to initiate the reaction. 
D)  acetic acid is being converted to sodium acetate. 
E)  the pH is not affected until all the acetic acid is consumed. 
A)  nothing is happening during this part of the titration. 
B)  the reaction is very slow during this part of the titration. 
C)  a more concentrated solution of NaOH needs to be present to initiate the reaction. 
D)  acetic acid is being converted to sodium acetate. 
E)  the pH is not affected until all the acetic acid is consumed.

Question 8

What are the characteristics of a pH indicator? A pH indicator __________
(I) is a weak acid.
(II) has different characteristic colors in protonated and unprotonated forms.
(III) changes color when the pH is near its pKa.

Accepted Answer

A)  I only 
B)  II only 
C)  both II and III 
D)  I, II, and III 
E)  I and III 
A)  I only 
B)  II only 
C)  both II and III 
D)  I, II, and III 
E)  I and III

Question 9

Write the reaction and equilibrium constant that describes the autoionization of water.

Accepted Answer

2H₂O F1F1F1

Question 10

Carbon dioxide in the atmosphere dissolves in rainwater to make rain __________

Accepted Answer

A)  neutral. 
B)  acidic. 
C)  basic. 
D)  gray. 
E)  wet. 
A)  neutral. 
B)  acidic. 
C)  basic. 
D)  gray. 
E)  wet.

Question 11

Glycolic acid, which is a monoprotic acid and a constituent in sugar cane, has a pKa of 3.9. A 25.0 mL solution of glycolic acid is titrated to the stoichiometric point with 35.8 mL of 0.020 M sodium hydroxide solution. What is the pH of the resulting solution at the stoichiometric point?

Accepted Answer

A)  4.12 
B)  9.88 
C)  6.01 
D)  7.98 
E)  Sufficient information is not provided to determine the pH. 
A)  4.12 
B)  9.88 
C)  6.01 
D)  7.98 
E)  Sufficient information is not provided to determine the pH.

Question 12

Calculate the pH of a solution that is 0.30 M in ammonia (NH3) and 0.20 M in ammonium chloride
(NH4Cl, Ka = 5.62 F1F1F1S1F1F1F10 10-10).

Accepted Answer

Question 13

Magnesium sulfate can be obtained at a drugstore as Epsom salts. The monohydrate is found as the mineral kieserite. What would be the pH of a 500 mL aqueous solution containing 1.62 g kieserite? The   value for sulfuric acid is 1.2 F1F1F1S1F1F1F10 10-2.

Accepted Answer

A)  nearly 14 
B)  slightly above 7.00 
C)  7.00 
D)  slightly below 7.00 
E)  nearly 1.00 
A)  nearly 14 
B)  slightly above 7.00 
C)  7.00 
D)  slightly below 7.00 
E)  nearly 1.00

Question 14

One brand of extra-strength antacid tablets contains 750 mg of calcium carbonate (100 g/mol) in each tablet. Stomach acid is essentially a hydrochloric acid solution. Is so much calcium carbonate really needed to neutralize stomach acid? Calculate the volume of stomach acid with a pH of 1.0 that one of these tablets could neutralize, and compare that value with the normal volume of stomach fluid, which usually is about 100 mL. One tablet can neutralize __________ mL of stomach acid at a pH of 1.0.

Accepted Answer

A)  75 
B)  150 
C)  250 
D)  15 
E)  7.5 
A)  75 
B)  150 
C)  250 
D)  15 
E)  7.5

Question 15

Which one of the following is not a strong base?

Accepted Answer

A)  lithium hydroxide, LiOH 
B)  sodium hydroxide, NaOH 
C)  potassium hydroxide, KOH 
D)  calcium hydroxide, Ca(OH)2 
E)  ammonium hydroxide, NH4OH 
A)  lithium hydroxide, LiOH 
B)  sodium hydroxide, NaOH 
C)  potassium hydroxide, KOH 
D)  calcium hydroxide, Ca(OH)2 
E)  ammonium hydroxide, NH4OH

Question 16

Use the following acid ionization constants to identify the correct decreasing order of base strengths. HF
Ka = 7.2 F1F1F1S1F1F1F10 10-4
HNO2
Ka = 4.5 F1F1F1S1F1F1F10 10-4
HCN
Ka = 6.2 F1F1F1S1F1F1F10 10-10

Accepted Answer

A)  CN- > NO2- > F- 
B)  NO2- > F- > CN- 
C)  F- >  CN- > NO2- 
D)  F- > NO2- > CN- 
E)  NO2- > CN- > F- 
A)  CN- > NO2- > F- 
B)  NO2- > F- > CN- 
C)  F- >  CN- > NO2- 
D)  F- > NO2- > CN- 
E)  NO2- > CN- > F-

Question 17

At what point in the following titration curve for a weak acid being titrated with a strong base is the pH equal to the pKa of the acid? The x-axis scale goes from 0.0 mL to 20.0 mL. The sharp rise is at 10.0 mL.

Accepted Answer

A)  0.0 mL 
B)  5.0 mL 
C)  9.0 mL 
D)  10.0 mL 
E)  18.0 mL 
A)  0.0 mL 
B)  5.0 mL 
C)  9.0 mL 
D)  10.0 mL 
E)  18.0 mL

Question 18

A buffer system is set up with [HA] = 2[A-]. If pKa = 5.5, what is the pH of the buffer?

Accepted Answer

A)  5.2 
B)  5.8 
C)  7.5 
D)  3.5 
E)  7.0 
A)  5.2 
B)  5.8 
C)  7.5 
D)  3.5 
E)  7.0

Question 19

What is the pH of a 0.15 M solution of ammonium bromide? The Kb value for ammonia is 1.8 F1F1F1S1F1F1F10 10-5.

Accepted Answer

A)  11.22 
B)  7.00 
C)  2.78 
D)  5.04 
E)  10.08 
A)  11.22 
B)  7.00 
C)  2.78 
D)  5.04 
E)  10.08

Question 20

Which one of the following, A-D, is correct? If all are correct, respond E.

Accepted Answer

A)  K2SO3 is a stronger base than KHSO3. 
B)  K2CO3 is a weaker base than KHCO3. 
C)  NaHSO3 is a stronger acid than NaHSO4. 
D)  Na2HPO4 is a weaker base than NaH2PO4. 
E)  All of these statements are correct. 
A)  K2SO3 is a stronger base than KHSO3. 
B)  K2CO3 is a weaker base than KHCO3. 
C)  NaHSO3 is a stronger acid than NaHSO4. 
D)  Na2HPO4 is a weaker base than NaH2PO4. 
E)  All of these statements are correct.

A cleaning solution has a pOH of 4.0. What is the pH and hydronium ion concentration of this solution?

The base ionization constant K_b describes which of the following reactions for a weak base, B, in aqueous solution?

Acid-base indicators change color __________

A solution that contains a weak acid and its conjugate base in roughly equal concentrations is __________

A solution with a pOH of 6.92 has an [OH^-] concentration of __________

When an acetic acid solution is titrated with sodium hydroxide, the slope of the titration curve (pH vs volume of NaOH added) increases when sodium hydroxide is first added. This change shows that __________.

What are the characteristics of a pH indicator? A pH indicator __________ (I) is a weak acid. (II) has different characteristic colors in protonated and unprotonated forms. (III) changes color when the pH is near its pK_a.

Write the reaction and equilibrium constant that describes the autoionization of water.

Carbon dioxide in the atmosphere dissolves in rainwater to make rain __________

Glycolic acid, which is a monoprotic acid and a constituent in sugar cane, has a pK_a of 3.9. A 25.0 mL solution of glycolic acid is titrated to the stoichiometric point with 35.8 mL of 0.020 M sodium hydroxide solution. What is the pH of the resulting solution at the stoichiometric point?

Calculate the pH of a solution that is 0.30 M in ammonia (NH₃) and 0.20 M in ammonium chloride (NH₄Cl, K_a = 5.62  10^-¹⁰).

Magnesium sulfate can be obtained at a drugstore as Epsom salts. The monohydrate is found as the mineral kieserite. What would be the pH of a 500 mL aqueous solution containing 1.62 g kieserite? The value for sulfuric acid is 1.2  10^-².

Which one of the following is not a strong base?

Use the following acid ionization constants to identify the correct decreasing order of base strengths. HF K_a = 7.2  10^-⁴ HNO₂ K_a = 4.5  10^-⁴ HCN K_a = 6.2  10^-¹⁰

At what point in the following titration curve for a weak acid being titrated with a strong base is the pH equal to the pK_a of the acid? The x-axis scale goes from 0.0 mL to 20.0 mL. The sharp rise is at 10.0 mL.

A buffer system is set up with [HA] = 2[A^-]. If pK_a = 5.5, what is the pH of the buffer?

What is the pH of a 0.15 M solution of ammonium bromide? The K_b value for ammonia is 1.8  10^-⁵.

Which one of the following, A-D, is correct? If all are correct, respond E.

Matter, Energy, and the Origins of the Universe

Atoms, Ions, and Compounds

Chemical Reactions and Earths Composition

Solution Chemistry and the Hydrosphere

Thermochemistry

Properties of Gases: the Air We Breathe

Electrons in Atoms and Periodic Properties

Chemical Bonding and Climate Change

Molecular Geometry and Bonding Theories

Forces Between Ions and Molecules

Solutions and Their Colligative Properties

The Chemistry of Solids

Organic Chemistry: Fuels, Pharmaceuticals, and Materials

Thermodynamics: Spontaneous Processes, Entropy, and Free Energy

Chemical Kinetics

Chemical Equilibrium

The Colorful Chemistry of Metals

Electrochemistry and the Quest for Clean Energy

Biochemistry: the Compounds of Life

Nuclear Chemistry

Life and the Periodic Table

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Exam 17: Equilibrium in the Aqueous Phase

A cleaning solution has a pOH of 4.0. What is the pH and hydronium ion concentration of this solution?

The base ionization constant Kb describes which of the following reactions for a weak base, B, in aqueous solution?

Acid-base indicators change color __________

A solution that contains a weak acid and its conjugate base in roughly equal concentrations is __________

A solution with a pOH of 6.92 has an [OH-] concentration of __________

When an acetic acid solution is titrated with sodium hydroxide, the slope of the titration curve (pH vs volume of NaOH added) increases when sodium hydroxide is first added. This change shows that __________.

What are the characteristics of a pH indicator? A pH indicator __________ (I) is a weak acid. (II) has different characteristic colors in protonated and unprotonated forms. (III) changes color when the pH is near its pKa.

Write the reaction and equilibrium constant that describes the autoionization of water.

Carbon dioxide in the atmosphere dissolves in rainwater to make rain __________

Glycolic acid, which is a monoprotic acid and a constituent in sugar cane, has a pKa of 3.9. A 25.0 mL solution of glycolic acid is titrated to the stoichiometric point with 35.8 mL of 0.020 M sodium hydroxide solution. What is the pH of the resulting solution at the stoichiometric point?

Calculate the pH of a solution that is 0.30 M in ammonia (NH3) and 0.20 M in ammonium chloride (NH4Cl, Ka = 5.62  10-10).

Magnesium sulfate can be obtained at a drugstore as Epsom salts. The monohydrate is found as the mineral kieserite. What would be the pH of a 500 mL aqueous solution containing 1.62 g kieserite? The value for sulfuric acid is 1.2  10-2.

Which one of the following is not a strong base?

Use the following acid ionization constants to identify the correct decreasing order of base strengths. HF Ka = 7.2  10-4 HNO2 Ka = 4.5  10-4 HCN Ka = 6.2  10-10

At what point in the following titration curve for a weak acid being titrated with a strong base is the pH equal to the pKa of the acid? The x-axis scale goes from 0.0 mL to 20.0 mL. The sharp rise is at 10.0 mL.

A buffer system is set up with [HA] = 2[A-]. If pKa = 5.5, what is the pH of the buffer?

What is the pH of a 0.15 M solution of ammonium bromide? The Kb value for ammonia is 1.8  10-5.

Which one of the following, A-D, is correct? If all are correct, respond E.

Matter, Energy, and the Origins of the Universe

Atoms, Ions, and Compounds

Chemical Reactions and Earths Composition

Solution Chemistry and the Hydrosphere

Thermochemistry

Properties of Gases: the Air We Breathe

Electrons in Atoms and Periodic Properties

Chemical Bonding and Climate Change

Molecular Geometry and Bonding Theories

Forces Between Ions and Molecules

Solutions and Their Colligative Properties

The Chemistry of Solids

Organic Chemistry: Fuels, Pharmaceuticals, and Materials

Thermodynamics: Spontaneous Processes, Entropy, and Free Energy

Chemical Kinetics

Chemical Equilibrium

The Colorful Chemistry of Metals

Electrochemistry and the Quest for Clean Energy

Biochemistry: the Compounds of Life

Nuclear Chemistry

Life and the Periodic Table

Filters

The base ionization constant K_b describes which of the following reactions for a weak base, B, in aqueous solution?

A solution with a pOH of 6.92 has an [OH^-] concentration of __________

What are the characteristics of a pH indicator? A pH indicator __________ (I) is a weak acid. (II) has different characteristic colors in protonated and unprotonated forms. (III) changes color when the pH is near its pK_a.

Glycolic acid, which is a monoprotic acid and a constituent in sugar cane, has a pK_a of 3.9. A 25.0 mL solution of glycolic acid is titrated to the stoichiometric point with 35.8 mL of 0.020 M sodium hydroxide solution. What is the pH of the resulting solution at the stoichiometric point?

Calculate the pH of a solution that is 0.30 M in ammonia (NH₃) and 0.20 M in ammonium chloride (NH₄Cl, K_a = 5.62  10^-¹⁰).

Magnesium sulfate can be obtained at a drugstore as Epsom salts. The monohydrate is found as the mineral kieserite. What would be the pH of a 500 mL aqueous solution containing 1.62 g kieserite? The value for sulfuric acid is 1.2  10^-².

Use the following acid ionization constants to identify the correct decreasing order of base strengths. HF K_a = 7.2  10^-⁴ HNO₂ K_a = 4.5  10^-⁴ HCN K_a = 6.2  10^-¹⁰

At what point in the following titration curve for a weak acid being titrated with a strong base is the pH equal to the pK_a of the acid? The x-axis scale goes from 0.0 mL to 20.0 mL. The sharp rise is at 10.0 mL.

A buffer system is set up with [HA] = 2[A^-]. If pK_a = 5.5, what is the pH of the buffer?

What is the pH of a 0.15 M solution of ammonium bromide? The K_b value for ammonia is 1.8  10^-⁵.