Question 1

Which of the following indicators would be the best to use when 0.050 M benzoic acid (Ka = 6.6 × 10−5)  is titrated with 0.05 MNaOH?

Accepted Answer

A)  Bromphenol blue, pH range: 3.0-4.5
B)  Bromcresol green, pH range: 3.8-5.4
C)  Alizarin, pH range: 5.7-7.2
D)  Phenol red, pH range: 6.9-8.2
E)  Phenolphthalein, pH range: 8.0-10.1F) B) and C)
G) A) and E)

Question 2

What is the pKa for the acid HA if a solution of 0.65 M HA and 0.85 M NaA has a pH of 4.75?

Accepted Answer

A)  
B)  4.63
C)  4.87
D)  5.02
E)  > 5.50F) D) and E)
G) A) and B)

Question 3

The pH of blood is 7.35. It is maintained in part by the buffer system composed of carbonic acid (H2CO3)  and the bicarbonate (hydrogen carbonate, HCO3−)  ion. What is the ratio of [bicarbonate]/[carbonic acid] at this pH? For carbonic acid, Ka1 = 4.2 × 10−7.

Accepted Answer

A)  [bicarbonate]/[carbonic acid] = 0.11
B)  [bicarbonate]/[carbonic acid] = 0.38
C)  [bicarbonate]/[carbonic acid] = 2.65
D)  [bicarbonate]/[carbonic acid] = 9.4
E)  None of these choices are correct.F) None of the above
G) A) and B)

Question 4

A 25.0-mL sample of 0.35 M HCOOH is titrated with 0.20 M KOH. What is the pH of the solution after 25.0 mL of KOH has been added to the acid? Ka = 1.77 × 10−4

Accepted Answer

A)  4.00
B)  3.88
C)  3.63
D)  3.51
E)  3.47F) B) and E)
G) C) and D)

Question 5

A diprotic acid H2A has Ka1 = 1 × 10−4 and Ka2 = 1 × 10−8. The corresponding base A2− is titrated with aqueous HCl, both solutions being 0.1 mol L−1. Which one of the following diagrams best represents the titration curve which will be seen? 2A has Ka1 = 1 × 10−4 and Ka2 = 1 × 10−8. The corresponding base A2− is titrated with aqueous HCl, both solutions being 0.1 mol L−1. Which one of the following diagrams best represents the titration curve which will be seen?   A) A B) B C) C D) D E) E" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  A
B)  B
C)  C
D)  D
E)  EF) C) and E)
G) B) and C)

Question 6

The solubility of magnesium phosphate is 2.27 × 10−3 g/1.0 L of solution. What is the Ksp for Mg3(PO4) 2?

Accepted Answer

A)  6.5 × 10 −12
B)  6.0 × 10 −14
C)  5.2 × 10 −24
D)  4.8 × 10 −26
E)  1.0 × 10 −26F) A) and E)
G) A) and B)

Question 7

What will be the effect of adding 0.5 mL of 0.1 M NaOH to 100 mL of an acetate buffer in which [CH3COOH] = [CH3COO−] = 0.5 M?

Accepted Answer

A)  The pH will increase slightly.
B)  The pH will increase significantly.
C)  The pH will decrease slightly.
D)  The pH will decrease significantly.
E)  Since it is a buffer solution, the pH will not be affected.F) A) and E)
G) C) and E)

Question 8

Which of the following substances has the greatest solubility in water?

Accepted Answer

A)  MgCO 3, K sp = 3.5 × 10 −8
B)  NiCO 3, K sp = 1.3 × 10 −7
C)  AgIO 3, K sp = 3.1 × 10 −8
D)  CuBr, K sp = 5.0 × 10 −9
E)  AgCN, K sp = 2.2 × 10 −16F) C) and D)
G) B) and D)

Question 9

Which one of the following aqueous solutions, when mixed with an equal volume of 0.10 mol L−1 aqueous NH3, will produce a buffer solution?

Accepted Answer

A)  0.10 mol L −1 HCl
B)  0.20 mol L −1 HCl
C)  0.10 mol L −1 CH 3COOH
D)  0.050 mol L −1 NaOH
E)  0.20 mol L −1 NH 4ClF) C) and D)
G) None of the above

Question 10

What is the [H3O+] in a solution that consists of 1.5 M NH3 and 2.5 NH4Cl? Kb = 1.8 × 10−5

Accepted Answer

A)  1.1 × 10 −5 M
B)  3.0 × 10 −6 M
C)  3.3 × 10 −9 M
D)  9.3 × 10 −10 M
E)  None of these choices are correct.F) A) and E)
G) All of the above

Question 11

Which of the following substances has the greatest solubility in water?

Accepted Answer

A)  Ba(IO 3) 2, K sp = 1.5 × 10 −9
B)  PbF 2, K sp = 3.6 × 10 −8
C)  SrSO 4, K sp = 3.2 × 10 −7
D)  CuCl, K sp = 1.9 × 10 −7
E)  CdS, K sp = 1.0 × 10 −24F) None of the above
G) B) and D)

Question 12

When 0.300 g of a diprotic acid was titrated with 0.100 M LiOH, 40.0 mL of the LiOH solution was needed to reach the second equivalence point. Identify the formula of the diprotic acid.

Accepted Answer

A)  H 2S
B)  H 2C 2O 4
C)  H 2C 4H 4O 6
D)  H 2Se
E)  H 2TeF) C) and E)
G) A) and B)

Question 13

Calculate the solubility of barium carbonate, BaCO3, in pure water. Ksp = 2.0 × 10−9

Accepted Answer

A)  1.3 × 10 −3  M
B)  3.2 × 10 −5  M
C)  2.2 × 10 −5  M
D)  4.5 × 10 −5  M
E)  4.0 × 10 −18  MF) A) and E)
G) C) and D)

Question 14

Barium sulfate (BaSO4)  is a slightly soluble salt, with Ksp = 1.1 × 10−10. What mass of Ba2+ ions will be present in 1.0 L of a saturated solution of barium sulfate?

Accepted Answer

A)  −7 g
B)  1.0 × 10 −5 g
C)  0.0014 g
D)  0.0024 g
E)  > 0.05 gF) All of the above
G) A) and E)

Question 15

A solution is prepared by dissolving 20.0 g of K2HPO4 and 25.0 g of KH2PO4 in enough water to produce 1.0 L of solution. What is the pH of this buffer? For phosphoric acid (H3PO4) , Ka2 = 6.2 × 10−8.

Accepted Answer

A)  7.70
B)  7.42
C)  7.21
D)  7.00
E)  6.72F) A) and B)
G) C) and E)

Question 16

The solubility of calcium chromate is 1.56 × 10−3 g/100 mL of solution. What is the Ksp for CaCrO4?

Accepted Answer

A)  2.4 × 10 −4
B)  1.5 × 10 −5
C)  7.6 × 10 −6
D)  1.0 × 10 −8
E)  −8F) A) and B)
G) None of the above

Question 17

Calculate the molar solubility of silver carbonate in 1.0 M sodium carbonate solution. (Ksp for Ag2CO3 = 8.1 x 10-12)

Accepted Answer

A)  8.1 x 10 -12 M
B)  2.8 x 10 -6 M
C)  1.4 x 10 -6 M
D)  1.4 x 10 -8 M
E)  2.0 x 10 -4 MF) B) and C)
G) A) and B)

Question 18

Use the following information to calculate the solubility product constant, Ksp, for PbCl2. A saturated solution of PbCl2 in water was prepared and filtered. From the filtrate, 1.0 L was measured out into a beaker and evaporated to dryness. The solid PbCl2residue recovered in the beaker amounted to 0.0162 moles.

Accepted Answer

A)  K sp = 6.9 × 10 −8
B)  K sp = 4.3 × 10 −6
C)  K sp = 1.7 × 10 −5
D)  K sp = 2.6 × 10 −4
E)  K sp = 3.2 × 10 −2F) B) and C)
G) B) and D)

Question 19

Which one of the following is the best representation of the titration curve that will be obtained in the titration of a weak base (0.10 mol L−1)  with HCl of the same concentration? −1)  with HCl of the same concentration?   A) A B) B C) C D) D E) E" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  A
B)  B
C)  C
D)  D
E)  EF) B) and C)
G) A) and B)

Question 20

A buffer is prepared by adding 0.5 mol of solid sodium hydroxide to 1.0 L of 1.0 M acetic acid (CH3COOH) . What is the pH of the buffer?

Accepted Answer

A)  The pH will be pK a - 0.30, where pK a is that of acetic acid.
B)  The pH will be greater than the pK a for acetic acid.
C)  The pH will be less than the value in answer a.
D)  The pH will be equal to the pK a for acetic acid.
E)  More information is needed to solve the problem.F) B) and D)
G) C) and E)

Exam 19: Ionic Equilibria in Aqueous Systems

The pH of blood is 7.35. It is maintained in part by the buffer system composed of carbonic acid (H₂CO₃) and the bicarbonate (hydrogen carbonate, HCO₃⁻) ion. What is the ratio of [bicarbonate]/[carbonic acid] at this pH? For carbonic acid, K_a1 = 4.2 × 10⁻⁷.

Correct Answer
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Which of the following substances has the greatest solubility in water?

Correct Answer
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A solution is prepared by dissolving 20.0 g of K₂HPO₄ and 25.0 g of KH₂PO₄ in enough water to produce 1.0 L of solution. What is the pH of this buffer? For phosphoric acid (H₃PO₄) , K_a2 = 6.2 × 10⁻⁸.

Correct Answer
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What is the pK_a for the acid HA if a solution of 0.65 M HA and 0.85 M NaA has a pH of 4.75?

Correct Answer
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A 25.0-mL sample of 0.35 M HCOOH is titrated with 0.20 M KOH. What is the pH of the solution after 25.0 mL of KOH has been added to the acid? K_a = 1.77 × 10⁻⁴

Correct Answer
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Which one of the following aqueous solutions, when mixed with an equal volume of 0.10 mol L⁻¹ aqueous NH₃, will produce a buffer solution?

Correct Answer
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A buffer is prepared by adding 0.5 mol of solid sodium hydroxide to 1.0 L of 1.0 M acetic acid (CH₃COOH) . What is the pH of the buffer?

Correct Answer
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Calculate the solubility of barium carbonate, BaCO₃, in pure water. K_sp = 2.0 × 10⁻⁹

Correct Answer
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What is the [H₃O⁺] in a solution that consists of 1.5 M NH₃and 2.5 NH₄Cl? K_b = 1.8 × 10⁻⁵

Correct Answer
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Which of the following indicators would be the best to use when 0.050 M benzoic acid (K_a = 6.6 × 10⁻⁵) is titrated with 0.05 MNaOH?

Correct Answer
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Which one of the following is the best representation of the titration curve that will be obtained in the titration of a weak base (0.10 mol L⁻¹) with HCl of the same concentration?

Correct Answer
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When 0.300 g of a diprotic acid was titrated with 0.100 M LiOH, 40.0 mL of the LiOH solution was needed to reach the second equivalence point. Identify the formula of the diprotic acid.

Correct Answer
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A diprotic acid H₂A has K_a1 = 1 × 10⁻⁴ and K_a2 = 1 × 10⁻⁸. The corresponding base A²⁻ is titrated with aqueous HCl, both solutions being 0.1 mol L⁻¹. Which one of the following diagrams best represents the titration curve which will be seen?

Correct Answer
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Barium sulfate (BaSO₄) is a slightly soluble salt, with K_sp = 1.1 × 10⁻¹⁰. What mass of Ba²⁺ ions will be present in 1.0 L of a saturated solution of barium sulfate?

Correct Answer
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Calculate the molar solubility of silver carbonate in 1.0 M sodium carbonate solution. (K_sp for Ag₂CO₃ = 8.1 x 10^-12)

Correct Answer
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The solubility of magnesium phosphate is 2.27 × 10⁻³g/1.0 L of solution. What is the K_sp for Mg₃(PO₄) ₂?

Correct Answer
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Correct Answer
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The solubility of calcium chromate is 1.56 × 10⁻³ g/100 mL of solution. What is the K_sp for CaCrO₄?

Correct Answer
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Which of the following substances has the greatest solubility in water?

Correct Answer
verified

What will be the effect of adding 0.5 mL of 0.1 M NaOH to 100 mL of an acetate buffer in which [CH₃COOH] = [CH₃COO⁻] = 0.5 M?

Correct Answer
verified

Exam 19: Ionic Equilibria in Aqueous Systems

The pH of blood is 7.35. It is maintained in part by the buffer system composed of carbonic acid (H2CO3) and the bicarbonate (hydrogen carbonate, HCO3−) ion. What is the ratio of [bicarbonate]/[carbonic acid] at this pH? For carbonic acid, Ka1 = 4.2 × 10−7.

Correct AnswerverifiedShow Answer

Which of the following substances has the greatest solubility in water?

Correct AnswerverifiedShow Answer

A solution is prepared by dissolving 20.0 g of K2HPO4 and 25.0 g of KH2PO4 in enough water to produce 1.0 L of solution. What is the pH of this buffer? For phosphoric acid (H3PO4) , Ka2 = 6.2 × 10−8.

Correct AnswerverifiedShow Answer

What is the pKa for the acid HA if a solution of 0.65 M HA and 0.85 M NaA has a pH of 4.75?

Correct AnswerverifiedShow Answer

A 25.0-mL sample of 0.35 M HCOOH is titrated with 0.20 M KOH. What is the pH of the solution after 25.0 mL of KOH has been added to the acid? Ka = 1.77 × 10−4

Correct AnswerverifiedShow Answer

Which one of the following aqueous solutions, when mixed with an equal volume of 0.10 mol L−1 aqueous NH3, will produce a buffer solution?

Correct AnswerverifiedShow Answer

A buffer is prepared by adding 0.5 mol of solid sodium hydroxide to 1.0 L of 1.0 M acetic acid (CH3COOH) . What is the pH of the buffer?

Correct AnswerverifiedShow Answer

Calculate the solubility of barium carbonate, BaCO3, in pure water. Ksp = 2.0 × 10−9

Correct AnswerverifiedShow Answer

What is the [H3O+] in a solution that consists of 1.5 M NH3 and 2.5 NH4Cl? Kb = 1.8 × 10−5

Correct AnswerverifiedShow Answer

Which of the following indicators would be the best to use when 0.050 M benzoic acid (Ka = 6.6 × 10−5) is titrated with 0.05 MNaOH?

Correct AnswerverifiedShow Answer

Which one of the following is the best representation of the titration curve that will be obtained in the titration of a weak base (0.10 mol L−1) with HCl of the same concentration?

Correct AnswerverifiedShow Answer

When 0.300 g of a diprotic acid was titrated with 0.100 M LiOH, 40.0 mL of the LiOH solution was needed to reach the second equivalence point. Identify the formula of the diprotic acid.

Correct AnswerverifiedShow Answer

A diprotic acid H2A has Ka1 = 1 × 10−4 and Ka2 = 1 × 10−8. The corresponding base A2− is titrated with aqueous HCl, both solutions being 0.1 mol L−1. Which one of the following diagrams best represents the titration curve which will be seen?

Correct AnswerverifiedShow Answer

Barium sulfate (BaSO4) is a slightly soluble salt, with Ksp = 1.1 × 10−10. What mass of Ba2+ ions will be present in 1.0 L of a saturated solution of barium sulfate?

Correct AnswerverifiedShow Answer

Calculate the molar solubility of silver carbonate in 1.0 M sodium carbonate solution. (Ksp for Ag2CO3 = 8.1 x 10-12)

Correct AnswerverifiedShow Answer

The solubility of magnesium phosphate is 2.27 × 10−3 g/1.0 L of solution. What is the Ksp for Mg3(PO4) 2?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

The solubility of calcium chromate is 1.56 × 10−3 g/100 mL of solution. What is the Ksp for CaCrO4?

Correct AnswerverifiedShow Answer

Which of the following substances has the greatest solubility in water?

Correct AnswerverifiedShow Answer

What will be the effect of adding 0.5 mL of 0.1 M NaOH to 100 mL of an acetate buffer in which [CH3COOH] = [CH3COO−] = 0.5 M?

Correct AnswerverifiedShow Answer

The pH of blood is 7.35. It is maintained in part by the buffer system composed of carbonic acid (H₂CO₃) and the bicarbonate (hydrogen carbonate, HCO₃⁻) ion. What is the ratio of [bicarbonate]/[carbonic acid] at this pH? For carbonic acid, K_a1 = 4.2 × 10⁻⁷.

Correct Answer
verified

Correct Answer
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A solution is prepared by dissolving 20.0 g of K₂HPO₄ and 25.0 g of KH₂PO₄ in enough water to produce 1.0 L of solution. What is the pH of this buffer? For phosphoric acid (H₃PO₄) , K_a2 = 6.2 × 10⁻⁸.

Correct Answer
verified

What is the pK_a for the acid HA if a solution of 0.65 M HA and 0.85 M NaA has a pH of 4.75?

Correct Answer
verified

A 25.0-mL sample of 0.35 M HCOOH is titrated with 0.20 M KOH. What is the pH of the solution after 25.0 mL of KOH has been added to the acid? K_a = 1.77 × 10⁻⁴

Correct Answer
verified

Which one of the following aqueous solutions, when mixed with an equal volume of 0.10 mol L⁻¹ aqueous NH₃, will produce a buffer solution?

Correct Answer
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A buffer is prepared by adding 0.5 mol of solid sodium hydroxide to 1.0 L of 1.0 M acetic acid (CH₃COOH) . What is the pH of the buffer?

Correct Answer
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Calculate the solubility of barium carbonate, BaCO₃, in pure water. K_sp = 2.0 × 10⁻⁹

Correct Answer
verified

What is the [H₃O⁺] in a solution that consists of 1.5 M NH₃and 2.5 NH₄Cl? K_b = 1.8 × 10⁻⁵

Correct Answer
verified

Which of the following indicators would be the best to use when 0.050 M benzoic acid (K_a = 6.6 × 10⁻⁵) is titrated with 0.05 MNaOH?

Correct Answer
verified

Which one of the following is the best representation of the titration curve that will be obtained in the titration of a weak base (0.10 mol L⁻¹) with HCl of the same concentration?

Correct Answer
verified

Correct Answer
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A diprotic acid H₂A has K_a1 = 1 × 10⁻⁴ and K_a2 = 1 × 10⁻⁸. The corresponding base A²⁻ is titrated with aqueous HCl, both solutions being 0.1 mol L⁻¹. Which one of the following diagrams best represents the titration curve which will be seen?

Correct Answer
verified

Barium sulfate (BaSO₄) is a slightly soluble salt, with K_sp = 1.1 × 10⁻¹⁰. What mass of Ba²⁺ ions will be present in 1.0 L of a saturated solution of barium sulfate?

Correct Answer
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Calculate the molar solubility of silver carbonate in 1.0 M sodium carbonate solution. (K_sp for Ag₂CO₃ = 8.1 x 10^-12)

Correct Answer
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The solubility of magnesium phosphate is 2.27 × 10⁻³g/1.0 L of solution. What is the K_sp for Mg₃(PO₄) ₂?

Correct Answer
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Correct Answer
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The solubility of calcium chromate is 1.56 × 10⁻³ g/100 mL of solution. What is the K_sp for CaCrO₄?

Correct Answer
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Correct Answer
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What will be the effect of adding 0.5 mL of 0.1 M NaOH to 100 mL of an acetate buffer in which [CH₃COOH] = [CH₃COO⁻] = 0.5 M?

Correct Answer
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