Two buffer solutions are prepared using acetic acid and sodium acetate. Solution A contains 20.0 g of acetic acid (CH3COOH) and 5.0 g of sodium acetate CH3COONa). Solution B contains 10.0 g of acetic acid and 25.0 g of sodium acetate. What is the difference between the pH values of these two solutions? For acetic acid, Ka = 1.8 × 10−5.

A) 0.0 B) 1.0 C) 2.0 D) 2.3 E) 4.6 A) 0.0 B) 1.0 C) 2.0 D) 2.3 E) 4.6

What is the pH of a buffer that consists of 0.45 M CH3COOH and 0.35 M CH3COONa? Ka = 1.8 × 10−5

A) 4.49 B) 4.64 C) 4.85 D) 5.00 E) 5.52 A) 4.49 B) 4.64 C) 4.85 D) 5.00 E) 5.52

What is the [H3O+] in a solution that consists of 0.15 M C2N2H8 (ethylene diamine) and 0.35 C2N2H9Cl? Kb = 4.7 × 10−4

A) 2.0 × 10 −3 M B) 1.1 × 10 −3 M C) 6.3 × 10 −9 M D) 2.1 × 10 −10 M E) 5.0 × 10 −11 M A) 2.0 × 10 −3 M B) 1.1 × 10 −3 M C) 6.3 × 10 −9 M D) 2.1 × 10 −10 M E) 5.0 × 10 −11 M

What volume of 0.200 M KOH must be added to 17.5 mL of 0.135 M H3PO4 to reach the third equivalence point?

A) 3.94 mL B) 11.8 mL C) 17.5 mL D) 23.6 mL E) 35.4 mL A) 3.94 mL B) 11.8 mL C) 17.5 mL D) 23.6 mL E) 35.4 mL

What volume of 0.500 M H2SO4 is needed to react completely with 20.0 mL of 0.400 M LiOH?

A) 4.00 mL B) 8.00 mL C) 12.5 mL D) 16.0 mL E) 32.0 mL A) 4.00 mL B) 8.00 mL C) 12.5 mL D) 16.0 mL E) 32.0 mL

A buffer is to be prepared by adding solid sodium acetate to 0.10 M CH3COOH. Which of the following concentrations of sodium acetate will produce the most effective buffer?

A) 3.0 M CH 3COONa B) 2.5 M CH 3COONa C) 2.0 M CH 3COONa D) 1.5 M CH 3COONa E) 0.30 M CH 3COONa A) 3.0 M CH 3COONa B) 2.5 M CH 3COONa C) 2.0 M CH 3COONa D) 1.5 M CH 3COONa E) 0.30 M CH 3COONa

Exam 19: Ionic Equilibria in Aqueous Systems

Two buffer solutions are prepared using acetic acid and sodium acetate. Solution A contains 20.0 g of acetic acid (CH₃COOH) and 5.0 g of sodium acetate CH₃COONa). Solution B contains 10.0 g of acetic acid and 25.0 g of sodium acetate. What is the difference between the pH values of these two solutions? For acetic acid, K_a = 1.8 × 10⁻⁵.

(Multiple Choice)

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Question 21

A buffer is prepared by adding 150 mL of 1.0 M NaOH to 250 mL of 1.0 M NaH₂PO₄. How many moles of HCl must be added to this buffer solution to change the pH by 0.18 units? If necessary, assume the total volume remains unchanged at 400 mL.

(Multiple Choice)

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Question 22

The lab technician Anna Lytic adds 2.20 mol KOH to 1.00 L of 0.5 M Al(NO₃)₃. What is the concentration of aluminum ions after the aluminum nitrate has reacted with the potassium hydroxide? K_f= 3.0 × 10³³ for Al(OH)₄⁻

(Multiple Choice)

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Question 23

What is the pH of a buffer that consists of 0.45 M CH₃COOH and 0.35 M CH₃COONa? K_a = 1.8 × 10⁻⁵

(Multiple Choice)

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Question 24

What is the [H₃O⁺] in a solution that consists of 0.15 M C₂N₂H₈(ethylene diamine) and 0.35 C₂N₂H₉Cl? K_b = 4.7 × 10⁻⁴

(Multiple Choice)

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Question 25

A 20.0-mL sample of 0.25 M HNO₃is titrated with 0.15 M NaOH. What is the pH of the solution after 30.0 mL of NaOH have been added to the acid?

(Multiple Choice)

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Question 26

The solubility of silver chromate is 0.0287 g/1.0 L of solution. What is the K_sp for Ag₂CrO₄?

(Multiple Choice)

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Question 27

An acetate buffer has a pH of 4.40. Which of the following changes will cause the pH to decrease?

(Multiple Choice)

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Question 28

What volume of 0.200 M KOH must be added to 17.5 mL of 0.135 M H₃PO₄to reach the third equivalence point?

(Multiple Choice)

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Question 29

What volume of 0.500 M H₂SO₄is needed to react completely with 20.0 mL of 0.400 M LiOH?

(Multiple Choice)

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Question 30

What will be the effect of adding 0.5 mL of 0.1 M HCl to 100 mL of a phosphate buffer in which [H₂PO₄⁻] = [HPO₄²⁻] = 0.35 M?

(Multiple Choice)

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Question 31

You need to use KH₂PO₄ and K₂HPO₄ to prepare a buffer with a pH of 7.45. Which of the following ratios of [base]/[acid] is required? For phosphoric acid, (H₃PO₄), K_a2 = 6.2 × 10⁻⁸.

(Multiple Choice)

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Question 32

Increasing the concentrations of the components of a buffer solution will increase the buffer range.

(True/False)

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Question 33

A solution is prepared by adding 500 mL of 0.3 M NaClO to 500 mL of 0.4 M HClO. What is the pH of this solution?

(Multiple Choice)

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Question 34

The concentration of the complex ion in each of following solutions is 1.00 M. In which of the solutions will the concentration of the uncomplexed metal ion be the greatest? Hg(CN)₄²⁻ K_f = 9.3 × 10³⁸ Be(OH)₄²⁻ K_f = 4.0 × 10¹⁸ Zn(OH)₄²⁻ K_f = 3.0 × 10¹⁵ Cu(NH₃)₄²⁺ K_f = 5.6 × 10¹¹ CdI₄²⁻ K_f = 1.0 × 10⁶

(Multiple Choice)

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Question 35

A 10.0-mL sample of 0.75 M CH₃CH₂COOH is titrated with 0.30 M NaOH. What is the pH of the solution after 22.0 mL of NaOH have been added to the acid? K_a = 1.3 × 10⁻⁵

(Multiple Choice)

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Question 36

If the pH of a buffer solution is greater than the pK_a value of the buffer acid, the buffer will have more capacity to neutralize added base than added acid.

(True/False)

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Question 37

Which of the following aqueous mixtures would be a buffer system?

(Multiple Choice)

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Question 38

A buffer is to be prepared by adding solid sodium acetate to 0.10 M CH₃COOH. Which of the following concentrations of sodium acetate will produce the most effective buffer?

(Multiple Choice)

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Question 39

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

(Multiple Choice)

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Question 40

Showing 21 - 40 of 114

Exam 19: Ionic Equilibria in Aqueous Systems

A buffer is prepared by adding 150 mL of 1.0 M NaOH to 250 mL of 1.0 M NaH2PO4. How many moles of HCl must be added to this buffer solution to change the pH by 0.18 units? If necessary, assume the total volume remains unchanged at 400 mL.

The lab technician Anna Lytic adds 2.20 mol KOH to 1.00 L of 0.5 M Al(NO3)3. What is the concentration of aluminum ions after the aluminum nitrate has reacted with the potassium hydroxide? Kf = 3.0 × 1033 for Al(OH)4−

What is the pH of a buffer that consists of 0.45 M CH3COOH and 0.35 M CH3COONa? Ka = 1.8 × 10−5

What is the [H3O+] in a solution that consists of 0.15 M C2N2H8 (ethylene diamine) and 0.35 C2N2H9Cl? Kb = 4.7 × 10−4

A 20.0-mL sample of 0.25 M HNO3 is titrated with 0.15 M NaOH. What is the pH of the solution after 30.0 mL of NaOH have been added to the acid?

The solubility of silver chromate is 0.0287 g/1.0 L of solution. What is the Ksp for Ag2CrO4?

An acetate buffer has a pH of 4.40. Which of the following changes will cause the pH to decrease?

What volume of 0.200 M KOH must be added to 17.5 mL of 0.135 M H3PO4 to reach the third equivalence point?

What volume of 0.500 M H2SO4 is needed to react completely with 20.0 mL of 0.400 M LiOH?

What will be the effect of adding 0.5 mL of 0.1 M HCl to 100 mL of a phosphate buffer in which [H2PO4−] = [HPO42−] = 0.35 M?

You need to use KH2PO4 and K2HPO4 to prepare a buffer with a pH of 7.45. Which of the following ratios of [base]/[acid] is required? For phosphoric acid, (H3PO4), Ka2 = 6.2 × 10−8.

Increasing the concentrations of the components of a buffer solution will increase the buffer range.

A solution is prepared by adding 500 mL of 0.3 M NaClO to 500 mL of 0.4 M HClO. What is the pH of this solution?

A 10.0-mL sample of 0.75 M CH3CH2COOH is titrated with 0.30 M NaOH. What is the pH of the solution after 22.0 mL of NaOH have been added to the acid? Ka = 1.3 × 10−5

If the pH of a buffer solution is greater than the pKa value of the buffer acid, the buffer will have more capacity to neutralize added base than added acid.

Which of the following aqueous mixtures would be a buffer system?

A buffer is to be prepared by adding solid sodium acetate to 0.10 M CH3COOH. Which of the following concentrations of sodium acetate will produce the most effective buffer?

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

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

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A buffer is prepared by adding 150 mL of 1.0 M NaOH to 250 mL of 1.0 M NaH₂PO₄. How many moles of HCl must be added to this buffer solution to change the pH by 0.18 units? If necessary, assume the total volume remains unchanged at 400 mL.

The lab technician Anna Lytic adds 2.20 mol KOH to 1.00 L of 0.5 M Al(NO₃)₃. What is the concentration of aluminum ions after the aluminum nitrate has reacted with the potassium hydroxide? K_f= 3.0 × 10³³ for Al(OH)₄⁻

What is the pH of a buffer that consists of 0.45 M CH₃COOH and 0.35 M CH₃COONa? K_a = 1.8 × 10⁻⁵

What is the [H₃O⁺] in a solution that consists of 0.15 M C₂N₂H₈(ethylene diamine) and 0.35 C₂N₂H₉Cl? K_b = 4.7 × 10⁻⁴

A 20.0-mL sample of 0.25 M HNO₃is titrated with 0.15 M NaOH. What is the pH of the solution after 30.0 mL of NaOH have been added to the acid?

The solubility of silver chromate is 0.0287 g/1.0 L of solution. What is the K_sp for Ag₂CrO₄?

What volume of 0.200 M KOH must be added to 17.5 mL of 0.135 M H₃PO₄to reach the third equivalence point?

What volume of 0.500 M H₂SO₄is needed to react completely with 20.0 mL of 0.400 M LiOH?

What will be the effect of adding 0.5 mL of 0.1 M HCl to 100 mL of a phosphate buffer in which [H₂PO₄⁻] = [HPO₄²⁻] = 0.35 M?

You need to use KH₂PO₄ and K₂HPO₄ to prepare a buffer with a pH of 7.45. Which of the following ratios of [base]/[acid] is required? For phosphoric acid, (H₃PO₄), K_a2 = 6.2 × 10⁻⁸.

A 10.0-mL sample of 0.75 M CH₃CH₂COOH is titrated with 0.30 M NaOH. What is the pH of the solution after 22.0 mL of NaOH have been added to the acid? K_a = 1.3 × 10⁻⁵

If the pH of a buffer solution is greater than the pK_a value of the buffer acid, the buffer will have more capacity to neutralize added base than added acid.

A buffer is to be prepared by adding solid sodium acetate to 0.10 M CH₃COOH. Which of the following concentrations of sodium acetate will produce the most effective buffer?