Question 1

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

Accepted Answer

A)   3.76
B)   3.99
C)   4.34
D)   4.57
E)   5.66F) All of the above
G) C) and D)

Question 2

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) None of the above
G) C) and E)

Question 3

Equal volumes of the following pairs of solutions are mixed. Which pair will produce a buffer solution?

Accepted Answer

A)   0.10 mol L¯1 HCl and 0.05 mol L¯1 NaOH
B)   0.10 mol L¯1 HCl and 0.15 mol L¯1 NH3
C)   0.10 mol L¯1 HCl and 0.05 mol L¯1 NH3
D)   0.10 mol L¯1 HCl and 0.20 mol L¯1 CH3COOH
E)   0.10 mol L¯1 HCl and 0.20 mol L¯1 NaClF) A) and D)
G) B) and E)

Question 4

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

Accepted Answer

A)   Ba(IO3) 2, Ksp = 1.5 *10¯9
B)   PbF2, Ksp = 3.6 *10¯8
C)   SrSO4, Ksp = 3.2 * 10¯7
D)   CuCl, Ksp = 1.9 * 10¯7
E)   CdS, Ksp = 1.0 * 10¯24F) D) and E)
G) A) and B)

Question 5

When a weak acid is titrated with a strong 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 14.0 - pKb, where pKb is that of the base.F) D) and E)
G) A) and E)

Question 6

When a strong acid is titrated with a strong 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, but is not 3.5.
D)   is equal to the pKa of the acid.
E)   is equal to 3.5.F) A) and B)
G) A) and D)

Question 7

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

Accepted Answer

A)   PbI2, Ksp = 7.9 *10¯9
B)   BaF2, Ksp = 1.5 * 10¯6
C)   Ca(OH) 2, Ksp = 6.5 *10¯6
D)   Zn(IO3) 2, Ksp = 3.9 * 10¯6
E)   Ag2SO4, Ksp = 1.5 *10¯5F) C) and E)
G) A) and E) E

Question 8

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) C) and D)
G) All of the above

Question 9

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) B) and C)
G) C) and D)

Question 10

The solubility of lead(II)  chloride is 0.45 g/100 mL of solution. What is the Ksp of PbCl2?

Accepted Answer

A)   4.9 * 10¯2
B)   1.7 * 10¯5
C)   8.5 * 10¯6
D)   4.2 * 10¯6
E)   6F) B) and C)
G) A) and B) B

Question 11

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 B)
G) A) and C)

Question 12

What is the [H3O+] in a solution that consists of 1.2 M HClO and 2.3 M NaClO? Ka = 3.5 *10¯8

Accepted Answer

A)   7.8 * 10¯9 M
B)   1.8 * 10¯8 M
C)   6.7 * 10¯8 M
D)   1.6 *10¯7 M
E)   None of these choices is correct.F) C) and D)
G) A) and C)

Question 13

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) C) and D)

Question 14

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

Accepted Answer

A)   dissolving a small amount of Na2HPO4
B)   dissolving a small amount of NaH2PO4
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 waterF) A) and D)
G) C) and E)

Question 15

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 is correct.F) A) and B)
G) C) and D)

Question 16

When 20.0 mL of 0.15 M hydrochloric acid is mixed with 20.0 mL of 0.10 M sodium hydroxide, the pH of the resulting solution is

Accepted Answer

A)   0.00
B)   12.40
C)   1.60
D)   0.82
E)   7.00F) A) and B)
G) A) and C)

Question 17

You need to prepare a buffer solution with a pH of 4.00, using NaF and HF. What ratio of the ratio of [base]/[acid] should be used in making the buffer? For HF, Ka = 7.2 * 10¯4

Accepted Answer

A)   [base]/[acid] = 0.14
B)   [base]/[acid] = 0.42
C)   [base]/[acid] = 2.36
D)   [base]/[acid] = 7.20
E)   None of these choices is correct.F) A) and B)
G) C) and D)

Question 18

Which of the following acids should be used to prepare a buffer with a pH of 4.5?

Accepted Answer

A)   HOC6H4OCOOH, Ka = 1.0 *10¯3
B)   C6H4(COOH) 2, Ka = 2.9 *0 10¯4
C)   CH3COOH, Ka = 1.8 * 10¯5
D)   C5H5O5COOH, Ka = 4.0 * 10¯6
E)   HBrO, Ka = 2.3 * 10¯9F) D) and E)
G) B) and C)

Question 19

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

Accepted Answer

A) True 
 B)False  True

Question 20

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) B) and C)
G) B) and D)

Exam 19: Ionic Equilibria in Aqueous Systems

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

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

Equal volumes of the following pairs of solutions are mixed. Which pair will produce a buffer solution?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedE

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

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

Correct AnswerverifiedShow Answer

The solubility of lead(II) chloride is 0.45 g/100 mL of solution. What is the Ksp of PbCl2?

Correct AnswerverifiedB

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 1.2 M HClO and 2.3 M NaClO? Ka = 3.5 *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

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

When 20.0 mL of 0.15 M hydrochloric acid is mixed with 20.0 mL of 0.10 M sodium hydroxide, the pH of the resulting solution is

Correct AnswerverifiedShow Answer

You need to prepare a buffer solution with a pH of 4.00, using NaF and HF. What ratio of the ratio of [base]/[acid] should be used in making the buffer? For HF, Ka = 7.2 * 10¯4

Correct AnswerverifiedShow Answer

Which of the following acids should be used to prepare a buffer with a pH of 4.5?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedTrue

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

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

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

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E

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

Correct Answer
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The solubility of lead(II) chloride is 0.45 g/100 mL of solution. What is the K_sp of PbCl₂?

Correct Answer
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B

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 1.2 M HClO and 2.3 M NaClO? K_a = 3.5 *10¯⁸

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

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You need to prepare a buffer solution with a pH of 4.00, using NaF and HF. What ratio of the ratio of [base]/[acid] should be used in making the buffer? For HF, K_a = 7.2 * 10¯⁴

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

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True

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