Question 1

A sample of a monoprotic acid (HA)  weighing 0.384 g is dissolved in water and the solution is titrated with aqueous NaOH. If 30.0 mL of 0.100 M NaOH is required to reach the equivalence point, what is the molar mass of HA?

Accepted Answer

A)   37.0 g/mol
B)   81.0 g/mol
C)   128 g/mol
D)   20.3 g/mol
E)   211 g/molF) All of the above
G) A) and B)

Question 2

Which of the following has the highest buffer capacity?

Accepted Answer

A)   0.10 M H2PO4-/0.10 M HPO42-
B)   0.50 M H2PO4-/0.10 M HPO42-
C)   0.10 M H2PO4-/0.50 M HPO42-
D)   0.50 M H2PO4-/0.50 M HPO42-
E)   They all have the same buffer capacity.F) None of the above
G) All of the above

Question 3

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

Accepted Answer

A)   CH3COOH, NaH2PO4
B)   H2CO3, HCO3-
C)   H2PO4-, HCO3-
D)   HSO4-, HSO3-
E)   None of these choices are correct.F) A) and B)
G) B) and D)

Question 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?

Accepted Answer

A)   -7 g
B)   1.0 × 10-5 g
C)   0.0014 g
D)   0.0024 g
E)   > 0.05 gF) A) and B)
G) A) and E) C

Question 5

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?

Accepted Answer

A)   It is a buffer, pH > pKa of formic acid.
B)   It is a buffer, pH a of formic acid.
C)   It is a buffer, pH = pKa of formic acid.
D)   It is a buffer, pH = pKb of sodium formate.
E)   Since hydrochloric acid is a strong acid, this is not a buffer.F) B) and D)
G) A) and B)

Question 6

The salts X(NO3) 2 and 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. Using the Ksp values listed below, decide which aqueous reagent, if any, will definitely precipitate X+ before precipitating Y+ from solution. Given Ksp values:
XCl2, 1 × 10-5 YCl2, 1 × 10-10 X(OH) 2, 1 × 10-10 Y(OH) 2, 1 × 10-5

Accepted Answer

A)   1 M NaCl
B)   1 M HCl
C)   1 M HNO3
D)   1 M NaOH
E)   None of these choices are correct.F) A) and B)
G) All of the above

Question 7

Calculate the solubility of magnesium sulfate, MgSO4, when placed into a 0.10 M MgCl2 solution. Ksp = 5.9 × 10-3

Accepted Answer

A)   4.2 × 10-2 M
B)   5.9 × 10-2 M
C)   7.7 × 10-2 M
D)   3.5 × 10-5 M
E)   3.5 × 10-6 MF) A) and B)
G) None of the above

Question 8

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

Accepted Answer

A)   is greater than 7.0.
B)   is equal to 7.0.
C)   is less than 7.0.
D)   is equal to the pKa of the acid.
E)   is equal to the pKb of the base.F) C) and E)
G) All of the above

Question 9

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.

Accepted Answer

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 Ksp for cadmium nitrate to make meaningful predictions on this system.
E)   The presence of NaF will raise the solubility of Cd(NO3) 2.F) C) and E)
G) B) and C) A

Question 10

A buffer is prepared by adding 100 mL of 0.50 M sodium hydroxide to 100 mL of 0.75 M propanoic acid. Is this a buffer solution, and if so, what is its pH?

Accepted Answer

A)   It is a buffer, pH > pKa of propanoic acid.
B)   It is a buffer, pH a of propanoic acid.
C)   It is a buffer, pH = pKa of propanoic acid.
D)   It is a buffer, pH = pKb of sodium propanoate.
E)   Since sodium hydroxide is a strong base, this is not a buffer.F) C) and D)
G) A) and B)

Question 11

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- Kf = 9.3 × 1038
Be(OH)  42- Kf = 4.0 × 1018
Zn(OH)  42- Kf = 3.0 × 1015
Cu(NH3) 42+ Kf = 5.6 × 1011
CdI42- Kf = 1.0 × 106

Accepted Answer

A)   Hg2+
B)   Be2+
C)   Zn2+
D)   Cu2+
E)   Cd2+F) A) and D)
G) A) and C)

Question 12

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 D)
G) A) and C)

Question 13

Citric acid has an acid dissociation constant of 8.4 × 10-4. It would be most effective for preparation of a buffer with a pH of

Accepted Answer

A)   2.
B)   3.
C)   4.
D)   5.
E)   6.F) D) and E)
G) B) and E)

Question 14

The equivalence point in a titration is defined as the point when the indicator changes color.

Accepted Answer

A) True 
 B)False  False

Question 15

Which one of the following pairs of 0.100 mol L-1 solutions, when mixed, will produce a buffer solution?

Accepted Answer

A)   50. mL of aqueous CH3COOH and 25. mL of aqueous HCl
B)   50. mL of aqueous CH3COOH and 100. mL of aqueous NaOH
C)   50. mL of aqueous NaOH and 25. mL of aqueous HCl
D)   50. mL of aqueous CH3COONa and 25. mL of aqueous NaOH
E)   50. mL of aqueous CH3COOH and 25. mL of aqueous CH3COONaF) A) and B)
G) A) and E)

Question 16

What is the pH of a buffer that consists of 0.20 M NaH2PO4 and 0.40 M Na2HPO4? For NaH2PO4, Ka = 6.2 × 10-8

Accepted Answer

A)   6.51
B)   6.91
C)   7.51
D)   7.90
E)   8.13F) A) and D)
G) A) and E)

Question 17

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?

Accepted Answer

A)   2.95
B)   3.13
C)   10.87
D)   11.05
E)   13.14F) A) and E)
G) A) and B)

Question 18

The end point in a titration is defined as the point when the indicator changes color.

Accepted Answer

A) True 
 B)False

Question 19

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

Accepted Answer

A)   MgCO3, Ksp = 3.5 × 10-8
B)   NiCO3, Ksp = 1.3 × 10-7
C)   AgIO3, Ksp = 3.1 × 10-8
D)   CuBr, Ksp = 5.0 × 10-9
E)   AgCN, Ksp = 2.2 × 10-16F) A) and D)
G) A) and E)

Question 20

Assuming that the total volume does not change after 0.200 g of KCl is added to 1.0 L of a saturated aqueous solution of AgCl, calculate the number of moles of Ag+ ion in the solution after equilibrium has been reestablished. For AgCl, Ksp = 1.8 × 10-10.

Accepted Answer

A)   1.8 × 10-10 mol Ag+
B)   9.0 × 10-10 mol Ag+
C)   9.0 × 10-9 mol Ag+
D)   6.7 × 10-8 mol Ag+
E)   1.3 × 10-5 mol Ag+F) A) and D)
G) A) and C)

Exam 19: Ionic Equilibria in Aqueous Systems

A sample of a monoprotic acid (HA) weighing 0.384 g is dissolved in water and the solution is titrated with aqueous NaOH. If 30.0 mL of 0.100 M NaOH is required to reach the equivalence point, what is the molar mass of HA?

Correct Answer
verified

Which of the following has the highest buffer capacity?

Correct Answer
verified

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

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
verified
C

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?

Correct Answer
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Correct Answer
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Calculate the solubility of magnesium sulfate, MgSO₄, when placed into a 0.10 M MgCl₂ solution. K_sp = 5.9 × 10^-3

Correct Answer
verified

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

Correct Answer
verified

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.

Correct Answer
verified
A

A buffer is prepared by adding 100 mL of 0.50 M sodium hydroxide to 100 mL of 0.75 M propanoic acid. Is this a buffer solution, and if so, what is its pH?

Correct Answer
verified

Correct Answer
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What is the [H₃O⁺] in a solution that consists of 1.5 M NH₃ and 2.5 NH₄Cl? K_b = 1.8 × 10^-5

Correct Answer
verified

Citric acid has an acid dissociation constant of 8.4 × 10^-4. It would be most effective for preparation of a buffer with a pH of

Correct Answer
verified

The equivalence point in a titration is defined as the point when the indicator changes color.

Correct Answer
verified
False

Which one of the following pairs of 0.100 mol L^-1 solutions, when mixed, will produce a buffer solution?

Correct Answer
verified

What is the pH of a buffer that consists of 0.20 M NaH₂PO₄ and 0.40 M Na₂HPO₄? For NaH₂PO₄, Ka = 6.2 × 10^-8

Correct Answer
verified

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?

Correct Answer
verified

The end point in a titration is defined as the point when the indicator changes color.

Correct Answer
verified

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

Correct Answer
verified

Assuming that the total volume does not change after 0.200 g of KCl is added to 1.0 L of a saturated aqueous solution of AgCl, calculate the number of moles of Ag⁺ ion in the solution after equilibrium has been reestablished. For AgCl, K_sp = 1.8 × 10^-10.

Correct Answer
verified

Exam 19: Ionic Equilibria in Aqueous Systems

A sample of a monoprotic acid (HA) weighing 0.384 g is dissolved in water and the solution is titrated with aqueous NaOH. If 30.0 mL of 0.100 M NaOH is required to reach the equivalence point, what is the molar mass of HA?

Correct AnswerverifiedShow Answer

Which of the following has the highest buffer capacity?

Correct AnswerverifiedShow Answer

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

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 AnswerverifiedC

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?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Calculate the solubility of magnesium sulfate, MgSO4, when placed into a 0.10 M MgCl2 solution. Ksp = 5.9 × 10-3

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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.

Correct AnswerverifiedA

A buffer is prepared by adding 100 mL of 0.50 M sodium hydroxide to 100 mL of 0.75 M propanoic acid. Is this a buffer solution, and if so, what is its pH?

Correct AnswerverifiedShow Answer

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

Citric acid has an acid dissociation constant of 8.4 × 10-4. It would be most effective for preparation of a buffer with a pH of

Correct AnswerverifiedShow Answer

The equivalence point in a titration is defined as the point when the indicator changes color.

Correct AnswerverifiedFalse

Which one of the following pairs of 0.100 mol L-1 solutions, when mixed, will produce a buffer solution?

Correct AnswerverifiedShow Answer

What is the pH of a buffer that consists of 0.20 M NaH2PO4 and 0.40 M Na2HPO4? For NaH2PO4, Ka = 6.2 × 10-8

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

The end point in a titration is defined as the point when the indicator changes color.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Assuming that the total volume does not change after 0.200 g of KCl is added to 1.0 L of a saturated aqueous solution of AgCl, calculate the number of moles of Ag+ ion in the solution after equilibrium has been reestablished. For AgCl, Ksp = 1.8 × 10-10.

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

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
verified
C

Correct Answer
verified

Correct Answer
verified

Calculate the solubility of magnesium sulfate, MgSO₄, when placed into a 0.10 M MgCl₂ solution. K_sp = 5.9 × 10^-3

Correct Answer
verified

Correct Answer
verified

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.

Correct Answer
verified
A

Correct Answer
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Correct Answer
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What is the [H₃O⁺] in a solution that consists of 1.5 M NH₃ and 2.5 NH₄Cl? K_b = 1.8 × 10^-5

Correct Answer
verified

Citric acid has an acid dissociation constant of 8.4 × 10^-4. It would be most effective for preparation of a buffer with a pH of

Correct Answer
verified

Correct Answer
verified
False

Which one of the following pairs of 0.100 mol L^-1 solutions, when mixed, will produce a buffer solution?

Correct Answer
verified

What is the pH of a buffer that consists of 0.20 M NaH₂PO₄ and 0.40 M Na₂HPO₄? For NaH₂PO₄, Ka = 6.2 × 10^-8

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Assuming that the total volume does not change after 0.200 g of KCl is added to 1.0 L of a saturated aqueous solution of AgCl, calculate the number of moles of Ag⁺ ion in the solution after equilibrium has been reestablished. For AgCl, K_sp = 1.8 × 10^-10.

Correct Answer
verified