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.

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. 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.

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

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

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

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 M 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 M

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?

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 4Cl 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 4Cl

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?

A) A B) B C) C D) D E) E A) A B) B C) C D) D E) E

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.

A) 7.70 B) 7.42 C) 7.21 D) 7.00 E) 6.72 A) 7.70 B) 7.42 C) 7.21 D) 7.00 E) 6.72

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

A) 2.4 × 10 −4 B) 1.5 × 10 −5 C) 7.6 × 10 −6 D) 1.0 × 10 −8 E) −8 A) 2.4 × 10 −4 B) 1.5 × 10 −5 C) 7.6 × 10 −6 D) 1.0 × 10 −8 E) −8

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

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. 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.

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?

A) −7 g B) 1.0 × 10 −5 g C) 0.0014 g D) 0.0024 g E) > 0.05 g A) −7 g B) 1.0 × 10 −5 g C) 0.0014 g D) 0.0024 g E) > 0.05 g

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.

(Multiple Choice)

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Question 81

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

(Multiple Choice)

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Question 82

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.

(Multiple Choice)

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Question 83

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

(Multiple Choice)

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Question 84

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

(Multiple Choice)

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Question 85

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?

(Multiple Choice)

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Question 86

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?

(Multiple Choice)

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Question 87

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?

(Multiple Choice)

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Question 88

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?

(Multiple Choice)

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Question 89

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?

(Multiple Choice)

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Question 90

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

(Multiple Choice)

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Question 91

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?

(Multiple Choice)

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Question 92

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

(Multiple Choice)

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Question 93

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.

(Multiple Choice)

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Question 94

Use the following information to calculate the solubility product constant, K_sp, 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.

(Multiple Choice)

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Question 95

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

(Multiple Choice)

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Question 96

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

(Multiple Choice)

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Question 97

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

(Multiple Choice)

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Question 98

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?

(Multiple Choice)

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Question 99

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?

(Multiple Choice)

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Question 100

Showing 81 - 100 of 114

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.

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

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.

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

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

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?

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?

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?

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?

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?

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

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?

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

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.

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

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

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

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?

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?

Keys to the Study of Chemistry: Definitions, Units, and Problem Solving

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry: Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids, Solids, and Phase Changes

The Properties of Mixtures: Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Thermodynamics: Entropy, Free Energy, and Reaction Direction

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

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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.

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

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

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?

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?

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?

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?

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?

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

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?

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.

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

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

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

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?

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?