Question 1

A titration of an acid and base to the equivalence point results in a noticeably acidic solution.It is likely this titration involves

Accepted Answer

A) a strong acid and a weak base. 
B) a weak acid and a strong base. 
C) a weak acid and a weak base (where Ka equals Kb). 
D) a strong acid and a strong base. 
A) a strong acid and a weak base. 
B) a weak acid and a strong base. 
C) a weak acid and a weak base (where Ka equals Kb). 
D) a strong acid and a strong base. A

Question 2

Describe how to make a sodium formate (HCOONa)/formic acid (HCOOH)buffer that has a pH of 4.77.

Accepted Answer

Prepare a solution having a molar ratio of 10.0 mol HCOONa to 1.0 mol HCOOH.

Question 3

Write an equation showing the net reaction that occurs when a strong acid is added to a CO32-/HCO3- buffer solution (for carbonic acid, Ka1 = 4.2 * 10-7, Ka2 = 2.4 * 10-8):

Accepted Answer

CO₃^2- + H⁺ $\rarr$ HCO₃^- and HCO₃^-+ H⁺ $\rarr$H₂CO₃

Question 4

The molar solubility of manganese(II)carbonate is 4.2 * 10-6 M. What is Ksp for this compound?

Accepted Answer

A) 4.2 * 10-6 
B) 8.4 * 10-6 
C) 3.0 * 10-16 
D) 1.8 * 10-11 
E) 2.0 * 10-3 
A) 4.2 * 10-6 
B) 8.4 * 10-6 
C) 3.0 * 10-16 
D) 1.8 * 10-11 
E) 2.0 * 10-3

Question 5

The percent ionization of a weak acid HA is greater in a solution containing the salt NaA than it is in a solution of the weak acid only.

Accepted Answer

A) True 
 B)False

Question 6

Assuming equal concentrations of conjugate base and acid, which one of the following mixtures is suitable for making a buffer solution with an optimum pH of 4.6-4.8?

Accepted Answer

A) CH3COO2Na / CH3COOH (Ka = 1.8 * 10-5) 
B) NH3 / NH4Cl (Ka = 5.6 * 10-10) 
C) NaOCl / HOCl (Ka = 3.2 * 10-8) 
D) NaNO2 / HNO2 (Ka = 4.5 * 10-4) 
E) NaCl / HCl 
A) CH3COO2Na / CH3COOH (Ka = 1.8 * 10-5) 
B) NH3 / NH4Cl (Ka = 5.6 * 10-10) 
C) NaOCl / HOCl (Ka = 3.2 * 10-8) 
D) NaNO2 / HNO2 (Ka = 4.5 * 10-4) 
E) NaCl / HCl

Question 7

What volume of 0.200 M potassium hydroxide should be added to 300.mL of 0.150 M propanoic acid (C2H5COOH)to obtain a solution with a pH of 5.25? [Ka(C2H5COOH)= 1.34 * 10-5]

Accepted Answer

A) 32 mL 
B) 210 mL 
C) 160 mL 
D) 65 mL 
E) 13 mL 
A) 32 mL 
B) 210 mL 
C) 160 mL 
D) 65 mL 
E) 13 mL

Question 8

Solid sodium iodide is slowly added to a solution that is 0.0050 M Pb2+ and 0.0050 M Ag+.[Ksp (PbI2)= 1.4 * 10-8; Ksp (AgI)= 8.3 * 10-17] What compound will precipitate first?

Accepted Answer

The answer of Solid sodium iodide is slowly added to...

Question 9

Over what range of pH is a HOCl - NaOCl buffer effective?

Accepted Answer

A) pH 2.0 - pH 4.0 
B) pH 7.5 - pH 9.5 
C) pH 6.5 - pH 8.5 
D) pH 6.5 - pH 9.5 
E) pH 1.0 - pH 14.0 
A) pH 2.0 - pH 4.0 
B) pH 7.5 - pH 9.5 
C) pH 6.5 - pH 8.5 
D) pH 6.5 - pH 9.5 
E) pH 1.0 - pH 14.0

Question 10

Calculate the minimum concentration of Cr3+ that must be added to 0.095 M NaF in order to initiate a precipitate of chromium(III)fluoride.(For CrF3 , Ksp = 6.6 * 10-11.)

Accepted Answer

A) 0.023 M 
B) 0.032 M 
C) 7.7 * 10-8 M 
D) 2.9 * 10-9 M 
E) 6.9 * 10-10 M 
A) 0.023 M 
B) 0.032 M 
C) 7.7 * 10-8 M 
D) 2.9 * 10-9 M 
E) 6.9 * 10-10 M

Question 11

Ammonium chloride solutions are slightly acidic, so they are better solvents than water for insoluble substances such as Ca(OH)2. Identify two reactions that, added together, give the overall reaction below, and determine Kc for the overall reaction.
Ca(OH)2(s)+ 2NH4+(aq)   Ca2+(aq)+ 2NH3(aq)+ 2H2O
Given: Ksp for Ca(OH)2 is 4.0 * 10-8; Kb for NH3 is 1.8 * 10-5.

Accepted Answer

Ca(OH)₂(s) @#IMG-DLM& Ca²⁺(a

Question 12

Find the concentration of Pb2+ ions in a solution made by adding 5.00 g of lead(II)iodide to 500.mL of 0.150 M KI. [For PbI2, Ksp = 1.39 * 10-8.]

Accepted Answer

A) 3.04 * 10-4 M 
B) 1.54 * 10-7 M 
C) 6.18 * 10-7 M 
D) 1.52 * 10-4 M 
E) 9.27 * 10-8 M 
A) 3.04 * 10-4 M 
B) 1.54 * 10-7 M 
C) 6.18 * 10-7 M 
D) 1.52 * 10-4 M 
E) 9.27 * 10-8 M

Question 13

In which one of the following solutions will acetic acid have the greatest percent ionization?

Accepted Answer

A) 0.1 M CH3COOH 
B) 0.1 M CH3COOH dissolved in 1.0 M HCl 
C) 0.1 M CH3COOH plus 0.1 M CH3COONa 
D) 0.1 M CH3COOH plus 0.2 M CH3COONa 
A) 0.1 M CH3COOH 
B) 0.1 M CH3COOH dissolved in 1.0 M HCl 
C) 0.1 M CH3COOH plus 0.1 M CH3COONa 
D) 0.1 M CH3COOH plus 0.2 M CH3COONa

Question 14

A 50.0 mL sample of 2.0 * 10-4 M CuNO3 is added to 50.0 mL of 4.0 M NaCN. The formation constant of the complex ion Cu(CN)32- is 1.0 * 109. What is the copper(I)ion concentration in this system at equilibrium?

Accepted Answer

1.3 * 10<s

Question 15

The solubility of Ba(NO3)2 is 130.5 g/L at 0ºC. How many moles of dissolved salt are present in 4.0 L of a saturated solution of Ba(NO3)2 at 0ºC?

Accepted Answer

Question 16

Calculate the pH of a solution that is 0.15 M CH3COOH and 0.75 M CH3COONa.

Accepted Answer

Question 17

To 1.00 L of a 0.100 M aqueous solution of benzoic acid (C6H5COOH)is added 1.00 mL of 12.0 M HCl. What is the percentage ionization of the benzoic acid in the resulting solution? [Ka(C6H5COOH)= 6.5 * 10-5]

Accepted Answer

A) 3.3% 
B) 12% 
C) 1.3% 
D) 0.52% 
E) 0.065% 
A) 3.3% 
B) 12% 
C) 1.3% 
D) 0.52% 
E) 0.065%

Question 18

The molar solubility of magnesium carbonate is 1.8 * 10-4 mol/L. What is Ksp for this compound?

Accepted Answer

A) 1.8 * 10-4 
B) 3.6 * 10-4 
C) 1.3 * 10-7 
D) 3.2 * 10-8 
E) 2.8 * 10-14 
A) 1.8 * 10-4 
B) 3.6 * 10-4 
C) 1.3 * 10-7 
D) 3.2 * 10-8 
E) 2.8 * 10-14

Question 19

The Ksp of CaF2 is 4 * 10-11. What is the maximum concentration of Ca2+ possible in a 0.10 M NaF solution?

Accepted Answer

The answer of The Ksp of CaF2 is 4 *...

Question 20

What molar ratio of benzoate ion to benzoic acid would be required to prepare a buffer with a pH of 5.20? [Ka(C6H5COOH)= 6.5 * 10-5]

Accepted Answer

The answer of What molar ratio of benzoate ion to...

Exam 16: Acid-Base Equilibria and Solubility Equilibria

A titration of an acid and base to the equivalence point results in a noticeably acidic solution.It is likely this titration involves

Describe how to make a sodium formate (HCOONa)/formic acid (HCOOH)buffer that has a pH of 4.77.

Write an equation showing the net reaction that occurs when a strong acid is added to a CO32-/HCO3- buffer solution (for carbonic acid, Ka1 = 4.2 * 10-7, Ka2 = 2.4 * 10-8):

The molar solubility of manganese(II)carbonate is 4.2 * 10-6 M. What is Ksp for this compound?

The percent ionization of a weak acid HA is greater in a solution containing the salt NaA than it is in a solution of the weak acid only.

Assuming equal concentrations of conjugate base and acid, which one of the following mixtures is suitable for making a buffer solution with an optimum pH of 4.6-4.8?

What volume of 0.200 M potassium hydroxide should be added to 300.mL of 0.150 M propanoic acid (C2H5COOH)to obtain a solution with a pH of 5.25? [Ka(C2H5COOH)= 1.34 * 10-5]

Solid sodium iodide is slowly added to a solution that is 0.0050 M Pb2+ and 0.0050 M Ag+.[Ksp (PbI2)= 1.4 * 10-8; Ksp (AgI)= 8.3 * 10-17] What compound will precipitate first?

Over what range of pH is a HOCl - NaOCl buffer effective?

Calculate the minimum concentration of Cr3+ that must be added to 0.095 M NaF in order to initiate a precipitate of chromium(III)fluoride.(For CrF3 , Ksp = 6.6 * 10-11.)

Find the concentration of Pb2+ ions in a solution made by adding 5.00 g of lead(II)iodide to 500.mL of 0.150 M KI. [For PbI2, Ksp = 1.39 * 10-8.]

In which one of the following solutions will acetic acid have the greatest percent ionization?

A 50.0 mL sample of 2.0 * 10-4 M CuNO3 is added to 50.0 mL of 4.0 M NaCN. The formation constant of the complex ion Cu(CN)32- is 1.0 * 109. What is the copper(I)ion concentration in this system at equilibrium?

The solubility of Ba(NO3)2 is 130.5 g/L at 0ºC. How many moles of dissolved salt are present in 4.0 L of a saturated solution of Ba(NO3)2 at 0ºC?

Calculate the pH of a solution that is 0.15 M CH3COOH and 0.75 M CH3COONa.

To 1.00 L of a 0.100 M aqueous solution of benzoic acid (C6H5COOH)is added 1.00 mL of 12.0 M HCl. What is the percentage ionization of the benzoic acid in the resulting solution? [Ka(C6H5COOH)= 6.5 * 10-5]

The molar solubility of magnesium carbonate is 1.8 * 10-4 mol/L. What is Ksp for this compound?

The Ksp of CaF2 is 4 * 10-11. What is the maximum concentration of Ca2+ possible in a 0.10 M NaF solution?

What molar ratio of benzoate ion to benzoic acid would be required to prepare a buffer with a pH of 5.20? [Ka(C6H5COOH)= 6.5 * 10-5]

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Write an equation showing the net reaction that occurs when a strong acid is added to a CO₃^2-/HCO₃^- buffer solution (for carbonic acid, K_a1 = 4.2 * 10^-7, K_a2 = 2.4 * 10^-8):

The molar solubility of manganese(II)carbonate is 4.2 * 10^-6 M. What is K_sp for this compound?

What volume of 0.200 M potassium hydroxide should be added to 300.mL of 0.150 M propanoic acid (C₂H₅COOH)to obtain a solution with a pH of 5.25? [K_a(C₂H₅COOH)= 1.34 * 10^-5]

Solid sodium iodide is slowly added to a solution that is 0.0050 M Pb²⁺ and 0.0050 M Ag⁺.[K_sp (PbI₂)= 1.4 * 10^-8; K_sp (AgI)= 8.3 * 10^-17] What compound will precipitate first?

Calculate the minimum concentration of Cr³⁺ that must be added to 0.095 M NaF in order to initiate a precipitate of chromium(III)fluoride.(For CrF₃, K_sp = 6.6 * 10^-11.)

Find the concentration of Pb²⁺ ions in a solution made by adding 5.00 g of lead(II)iodide to 500.mL of 0.150 M KI. [For PbI₂, K_sp = 1.39 * 10^-8.]

A 50.0 mL sample of 2.0 * 10^-4 M CuNO₃ is added to 50.0 mL of 4.0 M NaCN. The formation constant of the complex ion Cu(CN)₃^2- is 1.0 * 10⁹. What is the copper(I)ion concentration in this system at equilibrium?

The solubility of Ba(NO₃)₂ is 130.5 g/L at 0ºC. How many moles of dissolved salt are present in 4.0 L of a saturated solution of Ba(NO₃)₂ at 0ºC?

Calculate the pH of a solution that is 0.15 M CH₃COOH and 0.75 M CH₃COONa.

To 1.00 L of a 0.100 M aqueous solution of benzoic acid (C₆H₅COOH)is added 1.00 mL of 12.0 M HCl. What is the percentage ionization of the benzoic acid in the resulting solution? [K_a(C₆H₅COOH)= 6.5 * 10^-5]

The molar solubility of magnesium carbonate is 1.8 * 10^-4 mol/L. What is K_sp for this compound?

The K_sp of CaF₂ is 4 * 10^-11. What is the maximum concentration of Ca²⁺ possible in a 0.10 M NaF solution?

What molar ratio of benzoate ion to benzoic acid would be required to prepare a buffer with a pH of 5.20? [K_a(C₆H₅COOH)= 6.5 * 10^-5]