A phosphate buffer (H2PO4−/HPO42−) has a pH of 8.3. Which of the following changes will cause the pH to increase?

A) Dissolving a small amount of Na 2HPO 4 B) Dissolving a small amount of NaH 2PO 4 C) Adding a small amount of dilute hydrochloric acid D) Adding a small amount of dilute phosphoric acid E) Making the buffer more concentrated by removing some water A) Dissolving a small amount of Na 2HPO 4 B) Dissolving a small amount of NaH 2PO 4 C) Adding a small amount of dilute hydrochloric acid D) Adding a small amount of dilute phosphoric acid E) Making the buffer more concentrated by removing some water

What is the pH of a solution that consists of 0.50 M H2C6H6O6 (ascorbic acid) and 0.75 M NaHC6H6O6 (sodium ascorbate)? For ascorbic acid, Ka = 6.8 × 10−5

A) 3.76 B) 3.99 C) 4.34 D) 4.57 E) 5.66 A) 3.76 B) 3.99 C) 4.34 D) 4.57 E) 5.66

A lab technician adds 0.015 mol of KOH to 1.00 L of 0.0010 M Ca(NO3)2. Ksp = 6.5 × 10−6 for Ca(OH)2). Which of the following statements is correct?

A) Calcium hydroxide precipitates until the solution is saturated. B) The solution is unsaturated and no precipitate forms. C) The concentration of calcium ions is reduced by the addition of the hydroxide ions. D) One must know K sp for calcium nitrate to make meaningful predictions on this system. E) The presence of KOH will raise the solubility of Ca(NO 3)2. A) Calcium hydroxide precipitates until the solution is saturated. B) The solution is unsaturated and no precipitate forms. C) The concentration of calcium ions is reduced by the addition of the hydroxide ions. D) One must know K sp for calcium nitrate to make meaningful predictions on this system. E) The presence of KOH will raise the solubility of Ca(NO 3)2.

A popular buffer solution consists of carbonate (CO32−) and hydrogen carbonate (HCO3−) conjugate acid-base pair. Which, if any, of the following such buffers has the highest buffer capacity?

A) 0.9 M CO 3 2− and 0.1 M HCO 3 − B) 0.1 M CO 3 2− and 0.9 M HCO 3 − C) 0.5 M CO 3 2− and 0.5 M HCO 3 − D) 0.1 M CO 3 2− and 0.1 M HCO 3 − E) They all have the same buffer capacity. A) 0.9 M CO 3 2− and 0.1 M HCO 3 − B) 0.1 M CO 3 2− and 0.9 M HCO 3 − C) 0.5 M CO 3 2− and 0.5 M HCO 3 − D) 0.1 M CO 3 2− and 0.1 M HCO 3 − E) They all have the same buffer capacity.

A buffer is prepared by adding 300.0 mL of 2.0 M NaOH to 500.0 mL of 2.0 M CH3COOH. What is the pH of this buffer? Ka = 1.8 × 10−5

A) 4.57 B) 4.52 C) 4.87 D) 4.92 E) 4.97 A) 4.57 B) 4.52 C) 4.87 D) 4.92 E) 4.97

A lab technician adds 0.20 mol of NaF to 1.00 L of 0.35 M cadmium nitrate, Cd(NO3)2. Which of the following statements is correct? Ksp = 6.44 × 10−3 for CdF2.

A) Cadmium fluoride precipitates until the solution is saturated. B) The solution is unsaturated and no precipitate forms. C) The solubility of cadmium fluoride is increased by the presence of additional fluoride ions. D) One must know K sp for cadmium nitrate to make meaningful predictions on this system. E) The presence of NaF will raise the solubility of Cd(NO 3)2. A) Cadmium fluoride precipitates until the solution is saturated. B) The solution is unsaturated and no precipitate forms. C) The solubility of cadmium fluoride is increased by the presence of additional fluoride ions. D) One must know K sp for cadmium nitrate to make meaningful predictions on this system. E) The presence of NaF will raise the solubility of Cd(NO 3)2.

Exam 19: Ionic Equilibria in Aqueous Systems

A 25.0-mL sample of 0.10 M C₂H₃NH₂(ethylamine) is titrated with 0.15 M HCl. What is the pH of the solution after 9.00 mL of acid have been added to the amine? K_b = 6.5 × 10⁻⁴

(Multiple Choice)

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Question 41

Which of the following has the highest buffer capacity?

(Multiple Choice)

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Question 42

The salts X(NO₃)₂and Y(NO₃)₂ (where X⁺ and Y⁺ are metal ions) are dissolved in water to give a solution which is 0.1 M in each of them. Which of the answers gives the concentration of chloride ions will precipitate the most YCl₂ without precipitating any XCl₂? Given K_spvalues: XCl₂, 2 × 10⁻⁵YCl₂, 1 × 10⁻¹⁰

(Multiple Choice)

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Question 43

A phosphate buffer (H₂PO₄⁻/HPO₄²⁻) has a pH of 8.3. Which of the following changes will cause the pH to increase?

(Multiple Choice)

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Question 44

A 20.0-mL sample of 0.30 M HBr is titrated with 0.15 M NaOH. What is the pH of the solution after 40.3 mL of NaOH have been added to the acid?

(Multiple Choice)

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Question 45

Write the ion product expression for silver sulfide, Ag₂S.

(Multiple Choice)

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Question 46

A 20.0-mL sample of 0.50 M H₂C₆H₆O₆(ascorbic acid, a diprotic acid) was titrated with 0.50 M NaOH. The following data were gathered during the titration. What is K_a2 for ascorbic acid?

(Multiple Choice)

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Question 47

When a weak acid is titrated with a strong base, the pH at the equivalence point

(Multiple Choice)

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Question 48

What is the pH of a solution that consists of 0.50 M H₂C₆H₆O₆ (ascorbic acid) and 0.75 M NaHC₆H₆O₆(sodium ascorbate)? For ascorbic acid, K_a = 6.8 × 10⁻⁵

(Multiple Choice)

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Question 49

If 10.0 g of NaF and 20.0 g of HF are dissolved in water to make one liter of solution, what will the pH be? For HF, K_a = 6.8 × 10⁻⁴.

(Multiple Choice)

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Question 50

For a diprotic acid H₂A, the relationship K_a1 > K_a2 is always true.

(True/False)

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Question 51

A lab technician adds 0.015 mol of KOH to 1.00 L of 0.0010 M Ca(NO₃)₂. K_sp = 6.5 × 10⁻⁶ for Ca(OH)₂). Which of the following statements is correct?

(Multiple Choice)

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Question 52

A solution is prepared by adding 100 mL of 0.2 M hydrochloric acid to 100 mL of 0.4 M sodium formate. Is this a buffer solution, and if so, what is its pH?

(Multiple Choice)

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Question 53

A 25.0-mL sample of 1.00 M NH₃is titrated with 0.15 M HCl. What is the pH of the solution after 15.00 mL of acid have been added to the ammonia solution? K_b = 1.8 × 10⁻⁵

(Multiple Choice)

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Question 54

The solubility of aluminum hydroxide in water __________ when dilute nitric acid is added to it.

(Multiple Choice)

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Question 55

A popular buffer solution consists of carbonate (CO₃²⁻) and hydrogen carbonate (HCO₃⁻) conjugate acid-base pair. Which, if any, of the following such buffers has the highest buffer capacity?

(Multiple Choice)

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Question 56

A buffer is prepared by adding 300.0 mL of 2.0 M NaOH to 500.0 mL of 2.0 M CH₃COOH. What is the pH of this buffer? K_a = 1.8 × 10⁻⁵

(Multiple Choice)

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Question 57

Use the following information to calculate the solubility product constant, K_sp, for CuCl. A saturated solution of CuCl in water was prepared and filtered. From the filtrate, 1.0 L was measured out into a beaker and evaporated to dryness. The solid CuCl residue recovered in the beaker was found to weigh 0.041g.

(Multiple Choice)

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Question 58

A lab technician adds 0.20 mol of NaF to 1.00 L of 0.35 M cadmium nitrate, Cd(NO₃)₂. Which of the following statements is correct? K_sp = 6.44 × 10⁻³ for CdF₂.

(Multiple Choice)

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Question 59

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

(True/False)

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Question 60

Showing 41 - 60 of 114

Exam 19: Ionic Equilibria in Aqueous Systems

A 25.0-mL sample of 0.10 M C2H3NH2 (ethylamine) is titrated with 0.15 M HCl. What is the pH of the solution after 9.00 mL of acid have been added to the amine? Kb = 6.5 × 10−4

Which of the following has the highest buffer capacity?

A phosphate buffer (H2PO4−/HPO42−) has a pH of 8.3. Which of the following changes will cause the pH to increase?

A 20.0-mL sample of 0.30 M HBr is titrated with 0.15 M NaOH. What is the pH of the solution after 40.3 mL of NaOH have been added to the acid?

Write the ion product expression for silver sulfide, Ag2S.

A 20.0-mL sample of 0.50 M H2C6H6O6 (ascorbic acid, a diprotic acid) was titrated with 0.50 M NaOH. The following data were gathered during the titration. What is Ka2 for ascorbic acid?

When a weak acid is titrated with a strong base, the pH at the equivalence point

What is the pH of a solution that consists of 0.50 M H2C6H6O6 (ascorbic acid) and 0.75 M NaHC6H6O6 (sodium ascorbate)? For ascorbic acid, Ka = 6.8 × 10−5

If 10.0 g of NaF and 20.0 g of HF are dissolved in water to make one liter of solution, what will the pH be? For HF, Ka = 6.8 × 10−4.

For a diprotic acid H2A, the relationship Ka1 > Ka2 is always true.

A lab technician adds 0.015 mol of KOH to 1.00 L of 0.0010 M Ca(NO3)2. Ksp = 6.5 × 10−6 for Ca(OH)2). Which of the following statements is correct?

A solution is prepared by adding 100 mL of 0.2 M hydrochloric acid to 100 mL of 0.4 M sodium formate. Is this a buffer solution, and if so, what is its pH?

A 25.0-mL sample of 1.00 M NH3 is titrated with 0.15 M HCl. What is the pH of the solution after 15.00 mL of acid have been added to the ammonia solution? Kb = 1.8 × 10−5

The solubility of aluminum hydroxide in water __________ when dilute nitric acid is added to it.

A popular buffer solution consists of carbonate (CO32−) and hydrogen carbonate (HCO3−) conjugate acid-base pair. Which, if any, of the following such buffers has the highest buffer capacity?

A buffer is prepared by adding 300.0 mL of 2.0 M NaOH to 500.0 mL of 2.0 M CH3COOH. What is the pH of this buffer? Ka = 1.8 × 10−5

A lab technician adds 0.20 mol of NaF to 1.00 L of 0.35 M cadmium nitrate, Cd(NO3)2. Which of the following statements is correct? Ksp = 6.44 × 10−3 for CdF2.

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

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

Filters

A 25.0-mL sample of 0.10 M C₂H₃NH₂(ethylamine) is titrated with 0.15 M HCl. What is the pH of the solution after 9.00 mL of acid have been added to the amine? K_b = 6.5 × 10⁻⁴

A phosphate buffer (H₂PO₄⁻/HPO₄²⁻) has a pH of 8.3. Which of the following changes will cause the pH to increase?

Write the ion product expression for silver sulfide, Ag₂S.

A 20.0-mL sample of 0.50 M H₂C₆H₆O₆(ascorbic acid, a diprotic acid) was titrated with 0.50 M NaOH. The following data were gathered during the titration. What is K_a2 for ascorbic acid?

What is the pH of a solution that consists of 0.50 M H₂C₆H₆O₆ (ascorbic acid) and 0.75 M NaHC₆H₆O₆(sodium ascorbate)? For ascorbic acid, K_a = 6.8 × 10⁻⁵

If 10.0 g of NaF and 20.0 g of HF are dissolved in water to make one liter of solution, what will the pH be? For HF, K_a = 6.8 × 10⁻⁴.

For a diprotic acid H₂A, the relationship K_a1 > K_a2 is always true.

A lab technician adds 0.015 mol of KOH to 1.00 L of 0.0010 M Ca(NO₃)₂. K_sp = 6.5 × 10⁻⁶ for Ca(OH)₂). Which of the following statements is correct?

A 25.0-mL sample of 1.00 M NH₃is titrated with 0.15 M HCl. What is the pH of the solution after 15.00 mL of acid have been added to the ammonia solution? K_b = 1.8 × 10⁻⁵

A popular buffer solution consists of carbonate (CO₃²⁻) and hydrogen carbonate (HCO₃⁻) conjugate acid-base pair. Which, if any, of the following such buffers has the highest buffer capacity?

A buffer is prepared by adding 300.0 mL of 2.0 M NaOH to 500.0 mL of 2.0 M CH₃COOH. What is the pH of this buffer? K_a = 1.8 × 10⁻⁵

A lab technician adds 0.20 mol of NaF to 1.00 L of 0.35 M cadmium nitrate, Cd(NO₃)₂. Which of the following statements is correct? K_sp = 6.44 × 10⁻³ for CdF₂.