Question 1

A 1.0-liter solution contains 0.25 M HF and 0.33 M NaF (Ka for HF is 7.2 × 10-4) . If one adds 0.30 liters of 0.020 M KOH to the solution, what will be the change in pH?

Accepted Answer

A)   0.02
B)   3.28
C)   0.14
D)   -0.11
E)   -0.28

Question 2

A 50.00-mL solution of 0.0400 M hydrofluoric acid (Ka = 7.2 × 10-4)  is titrated with a 0.0153 M solution of NaOH as the titrant. What is the pH of at the equivalence point? (Kw = 1.00 × 10-14)

Accepted Answer

A)   7.59
B)   11.45
C)   6.41
D)   10.86
E)   3.14

Question 3

What is the molar solubility of Mn(OH) 2(s)  in a solution that is buffered at pH 8.00 at 25 °C? The Ksp of Mn(OH) 2 is 1.9 × 10-13 at 25 °C.

Accepted Answer

A)   3.6 × 10-8 mol/L
B)   1.9 × 10-7 mol/L
C)   3.6 × 10-5 mol/L
D)   1.9 × 10-1 mol/L
E)   1.9 × 103 mol/L

Question 4

Why do salts containing basic anions have a greater solubility in water than predicted from calculations using Ksp values? Examples of such salts are CaCO3, PbF2, and Ca3(PO4)2.

Accepted Answer

Basic anions react with water to form th...

Question 5

What is the pH of a buffer that results when 0.40 mol NaHCO2 is mixed with 100.0 mL of 2.00 M HCl(aq)  and diluted with water to 250 mL? (Ka of HCO2H = 1.8 × 10-4)

Accepted Answer

A)   −0.301
B)   3.05
C)   3.44
D)   3.74
E)   4.05

Question 6

The Ksp of BaSO4 is 1.1 × 10-10 at 25 °C. What mass of BaSO4 will dissolve in 1.0 L of water at 25 °C? (molar mass = 233.4 g/mol)

Accepted Answer

A)   2.6 × 10−8 g
B)   4.5 × 10−8 g
C)   1.0 × 10−5 g
D)   1.6 × 10−4 g
E)   2.4 × 10−3 g

Question 7

What is the concentration of Cd2+(aq)  in a mixture of 0.014 mol Cd(NO3) 2 and 1.0 mol NH3 diluted to 1.00 L? For Cd(NH3) 42+, Kf = 1.0 × 107.​

Accepted Answer

A)   3.7 × 10-5 M
B)   ​​1.5 × 10-9 M
C)   1.8 × 10-9 M
D)   3.2 × 10-4 M
E)   ​​1.4 × 10-2 M

Question 8

How many moles of solid NaF would have to be added to 1.0 L of 2.16 M HF solution to achieve a buffer of pH 3.35? Assume there is no volume change. (Ka for HF = 7.2 × 10-4)

Accepted Answer

A)   3.5
B)   0.45
C)   0.75
D)   1.0
E)   1.6

Question 9

The Ksp of Ca(OH) 2 is 5.5 × 10-5 at 25 °C. What is the concentration of OH-(aq)  in a saturated solution of Ca(OH) 2(aq) ?

Accepted Answer

A)   1.9 × 10-3 M
B)   7.4 × 10-3 M
C)   2.4 × 10-2 M
D)   4.0 × 10-2 M
E)   4.8 × 10-2 M

Question 10

What mass of sodium hydroxide must be added to 65.0 mL of 0.926 M acetic acid in order to create a buffer with a pH of 4.83? Ka for acetic acid is 1.8 × 10-5.

Accepted Answer

A)   49 g
B)   1.3 g
C)   1.0 g
D)   0 g
E)   2.4 g

Question 11

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

Accepted Answer

A)   less than 7
B)   greater than 7
C)   equal to 7
D)   equal to the acid pKa
E)   equal to the base pKb

Question 12

Calculate the molar concentration of uncomplexed Zn2+(aq)  in a solution that contains 0.17 M Zn(NH3) 42+ and 0.3775 M NH3 at equilibrium. Kf for Zn(NH3) 42+ is  2.9×1092.9 	imes 10 ^ { 9 }2.9×109  .

Accepted Answer

A)    2.9×10−92.9 	imes 10 ^ { - 9 }2.9×10−9  M
B)    1.6×10−101.6 	imes 10 ^ { - 10 }1.6×10−10  M
C)    3.5×1083.5 	imes 10 ^ { 8 }3.5×108  M
D)    4.1×10−104.1 	imes 10 ^ { - 10 }4.1×10−10  M
E)    2.7×1002.7 	imes 10 ^ { 0 }2.7×100  M

Question 13

A volume of 25.0 mL of 0.100 M C6H5CO2H(aq)  is titrated with 0.100 M NaOH(aq) . What is the pH after the addition of 12.5 mL of NaOH? (Ka of benzoic acid = 6.3 × 10-5)

Accepted Answer

A)   2.60
B)   4.20
C)   5.40
D)   7.00
E)   8.60

Question 14

An aqueous solution contains 0.010 M bromide ion (Br-)  and 0.010 M iodide ion (I-) . If silver ions (Ag+)  are added to the solution until silver bromide just begins to precipitate, what are the concentrations of silver ions and iodide ions? (Ksp of AgBr = 5.4 × 10-13 and Ksp of AgI = 8.5 × 10-17)

Accepted Answer

A)   [Ag+] = 5.4 × 10-11 M, [I-] = 1.0 × 10-2 M
B)   [Ag+] = 8.5 × 10-15 M, [I-] = 1.0 × 10-2 M
C)   [Ag+] = 5.4 × 10-11 M, [I-] = 1.6 × 10-6 M
D)   [Ag+] = 8.5 × 10-15 M, [I-] = 6.4 × 101 M
E)   [Ag+] = 8.5 × 10-15 M, [I-] = 1.6 × 10-6 M

Question 15

If 25 mL of 0.10 M NaOH is added to 40 mL of 0.20 M HC2H3O2, what is the pH of the resulting solution at 25°C? Ka for HC2H3O2 is 1.8 × 10-5 at 25°C.

Accepted Answer

A)   10.1
B)   4.2
C)   5.1
D)   2.7
E)   4.4

Question 16

Which of the following is the common name for iron(II)  carbonate?

Accepted Answer

A)   Siderite
B)   Calcite
C)   Barite
D)   Fluorite
E)   Celestite

Question 17

The solubility of strontium carbonate (SrCO3)  in water at 25°C is  4.5×10−34.5 	imes 10 ^ { - 3 }4.5×10−3  g/L. What is the Ksp of this sparingly soluble salt?

Accepted Answer

A)    9.3×10−109.3 	imes 10 ^ { - 10 }9.3×10−10 
B)    1.13×10−131.13 	imes 10 ^ { - 13 }1.13×10−13 
C)    2.34×10−172.34 	imes 10 ^ { - 17 }2.34×10−17 
D)    5.52×10−35.52 	imes 10 ^ { - 3 }5.52×10−3 
E)    3.12×10−23.12 	imes 10 ^ { - 2 }3.12×10−2

Question 18

The concentration of Pb2+ in an aqueous solution is 5.5 × 10-3 M. What concentration of SO42- is required to begin precipitating PbSO4? The Ksp of PbSO4 is 2.5 × 10-8.

Accepted Answer

A)   1.4 × 10-10 M
B)   4.5 × 10-6 M
C)   1.6 × 10-4 M
D)   8.3 × 10-4 M
E)   2.9 × 10-2 M

Question 19

All of the following statements concerning acid-base buffers are true EXCEPT

Accepted Answer

A)   buffers are resistant to pH changes upon addition of small quantities of strong acids or bases.
B)   buffers are used as colored indicators in acid-base titrations.
C)   the pH of a buffer is close to the pKa of the weak acid from which it is made.
D)   buffers contain appreciable quantities of a weak acid and its conjugate base.
E)   buffers are resistant to changes in pH when diluted with water.

Question 20

What is the pH of the buffer that results when 12.0 g of NaH2PO4 and 8.00 g of Na2HPO4 are diluted with water to a volume of 0.50 L? (Ka of H2PO4- = 6.2 × 10-8, the molar masses of NaH2PO4 and Na2HPO4 are 120.0 g/mol and 142.0 mol, respectively)

Accepted Answer

A)   4.10
B)   6.96
C)   7.21
D)   7.46
E)   9.90

Exam 18: Principles of Chemical Reactivity: Other Aspects of Aqueous Equilibria

What is the concentration of Cd²⁺(aq) in a mixture of 0.014 mol Cd(NO₃) ₂ and 1.0 mol NH₃ diluted to 1.00 L? For Cd(NH₃) ₄²⁺, K_f = 1.0 × 10⁷.

Correct Answer
verified

Calculate the molar concentration of uncomplexed Zn²⁺(aq) in a solution that contains 0.17 M Zn(NH₃) ₄²⁺ and 0.3775 M NH₃ at equilibrium. K_f for Zn(NH₃) ₄²⁺ is $2.9 \times 10 ^ { 9 }$ .

Correct Answer
verified

A 1.0-liter solution contains 0.25 M HF and 0.33 M NaF (K_a for HF is 7.2 × 10^-4) . If one adds 0.30 liters of 0.020 M KOH to the solution, what will be the change in pH?

Correct Answer
verified

What is the pH of the buffer that results when 12.0 g of NaH₂PO₄ and 8.00 g of Na₂HPO₄ are diluted with water to a volume of 0.50 L? (K_a of H₂PO₄^- = 6.2 × 10^-8, the molar masses of NaH₂PO₄ and Na₂HPO₄ are 120.0 g/mol and 142.0 mol, respectively)

Correct Answer
verified

What mass of sodium hydroxide must be added to 65.0 mL of 0.926 M acetic acid in order to create a buffer with a pH of 4.83? K_a for acetic acid is 1.8 × 10^-5.

Correct Answer
verified

The K_sp of BaSO₄ is 1.1 × 10^-10 at 25 °C. What mass of BaSO₄ will dissolve in 1.0 L of water at 25 °C? (molar mass = 233.4 g/mol)

Correct Answer
verified

The concentration of Pb²⁺ in an aqueous solution is 5.5 × 10^-3 M. What concentration of SO₄^2- is required to begin precipitating PbSO₄? The K_sp of PbSO₄ is 2.5 × 10^-8.

Correct Answer
verified

The solubility of strontium carbonate (SrCO₃) in water at 25°C is $4.5 \times 10 ^ { - 3 }$ g/L. What is the K_sp of this sparingly soluble salt?

Correct Answer
verified

If 25 mL of 0.10 M NaOH is added to 40 mL of 0.20 M HC₂H₃O₂, what is the pH of the resulting solution at 25°C? K_a for HC₂H₃O₂ is 1.8 × 10^-5 at 25°C.

Correct Answer
verified

What is the molar solubility of Mn(OH) ₂(s) in a solution that is buffered at pH 8.00 at 25 °C? The K_sp of Mn(OH) ₂ is 1.9 × 10^-13 at 25 °C.

Correct Answer
verified

How many moles of solid NaF would have to be added to 1.0 L of 2.16 M HF solution to achieve a buffer of pH 3.35? Assume there is no volume change. (K_a for HF = 7.2 × 10^-4)

Correct Answer
verified

A volume of 25.0 mL of 0.100 M C₆H₅CO₂H(aq) is titrated with 0.100 M NaOH(aq) . What is the pH after the addition of 12.5 mL of NaOH? (K_a of benzoic acid = 6.3 × 10^-5)

Correct Answer
verified

A 50.00-mL solution of 0.0400 M hydrofluoric acid (K_a = 7.2 × 10^-4) is titrated with a 0.0153 M solution of NaOH as the titrant. What is the pH of at the equivalence point? (K_w = 1.00 × 10^-14)

Correct Answer
verified

All of the following statements concerning acid-base buffers are true EXCEPT

Correct Answer
verified

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

Correct Answer
verified

Why do salts containing basic anions have a greater solubility in water than predicted from calculations using K_sp values? Examples of such salts are CaCO₃, PbF₂, and Ca₃(PO₄)₂.

Correct Answer
verified
Basic anions react with water to form th...
View Answer

Which of the following is the common name for iron(II) carbonate?

Correct Answer
verified

The K_sp of Ca(OH) ₂ is 5.5 × 10^-5 at 25 °C. What is the concentration of OH^-(aq) in a saturated solution of Ca(OH) ₂(aq) ?

Correct Answer
verified

Correct Answer
verified

What is the pH of a buffer that results when 0.40 mol NaHCO₂ is mixed with 100.0 mL of 2.00 M HCl(aq) and diluted with water to 250 mL? (K_a of HCO₂H = 1.8 × 10^-4)

Correct Answer
verified

Exam 18: Principles of Chemical Reactivity: Other Aspects of Aqueous Equilibria

What is the concentration of Cd2+(aq) in a mixture of 0.014 mol Cd(NO3) 2 and 1.0 mol NH3 diluted to 1.00 L? For Cd(NH3) 42+, Kf = 1.0 × 107.​

Correct AnswerverifiedShow Answer

Calculate the molar concentration of uncomplexed Zn2+(aq) in a solution that contains 0.17 M Zn(NH3) 42+ and 0.3775 M NH3 at equilibrium. Kf for Zn(NH3) 42+ is 2.9×1092.9 \times 10 ^ { 9 }2.9×109 .

Correct AnswerverifiedShow Answer

A 1.0-liter solution contains 0.25 M HF and 0.33 M NaF (Ka for HF is 7.2 × 10-4) . If one adds 0.30 liters of 0.020 M KOH to the solution, what will be the change in pH?

Correct AnswerverifiedShow Answer

What is the pH of the buffer that results when 12.0 g of NaH2PO4 and 8.00 g of Na2HPO4 are diluted with water to a volume of 0.50 L? (Ka of H2PO4- = 6.2 × 10-8, the molar masses of NaH2PO4 and Na2HPO4 are 120.0 g/mol and 142.0 mol, respectively)

Correct AnswerverifiedShow Answer

What mass of sodium hydroxide must be added to 65.0 mL of 0.926 M acetic acid in order to create a buffer with a pH of 4.83? Ka for acetic acid is 1.8 × 10-5.

Correct AnswerverifiedShow Answer

The Ksp of BaSO4 is 1.1 × 10-10 at 25 °C. What mass of BaSO4 will dissolve in 1.0 L of water at 25 °C? (molar mass = 233.4 g/mol)

Correct AnswerverifiedShow Answer

The concentration of Pb2+ in an aqueous solution is 5.5 × 10-3 M. What concentration of SO42- is required to begin precipitating PbSO4? The Ksp of PbSO4 is 2.5 × 10-8.

Correct AnswerverifiedShow Answer

The solubility of strontium carbonate (SrCO3) in water at 25°C is 4.5×10−34.5 \times 10 ^ { - 3 }4.5×10−3 g/L. What is the Ksp of this sparingly soluble salt?

Correct AnswerverifiedShow Answer

If 25 mL of 0.10 M NaOH is added to 40 mL of 0.20 M HC2H3O2, what is the pH of the resulting solution at 25°C? Ka for HC2H3O2 is 1.8 × 10-5 at 25°C.

Correct AnswerverifiedShow Answer

What is the molar solubility of Mn(OH) 2(s) in a solution that is buffered at pH 8.00 at 25 °C? The Ksp of Mn(OH) 2 is 1.9 × 10-13 at 25 °C.

Correct AnswerverifiedShow Answer

How many moles of solid NaF would have to be added to 1.0 L of 2.16 M HF solution to achieve a buffer of pH 3.35? Assume there is no volume change. (Ka for HF = 7.2 × 10-4)

Correct AnswerverifiedShow Answer

A volume of 25.0 mL of 0.100 M C6H5CO2H(aq) is titrated with 0.100 M NaOH(aq) . What is the pH after the addition of 12.5 mL of NaOH? (Ka of benzoic acid = 6.3 × 10-5)

Correct AnswerverifiedShow Answer

A 50.00-mL solution of 0.0400 M hydrofluoric acid (Ka = 7.2 × 10-4) is titrated with a 0.0153 M solution of NaOH as the titrant. What is the pH of at the equivalence point? (Kw = 1.00 × 10-14)

Correct AnswerverifiedShow Answer

All of the following statements concerning acid-base buffers are true EXCEPT

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Why do salts containing basic anions have a greater solubility in water than predicted from calculations using Ksp values? Examples of such salts are CaCO3, PbF2, and Ca3(PO4)2.

Correct AnswerverifiedBasic anions react with water to form th...View AnswerShow Answer

Which of the following is the common name for iron(II) carbonate?

Correct AnswerverifiedShow Answer

The Ksp of Ca(OH) 2 is 5.5 × 10-5 at 25 °C. What is the concentration of OH-(aq) in a saturated solution of Ca(OH) 2(aq) ?

Correct AnswerverifiedShow Answer

An aqueous solution contains 0.010 M bromide ion (Br-) and 0.010 M iodide ion (I-) . If silver ions (Ag+) are added to the solution until silver bromide just begins to precipitate, what are the concentrations of silver ions and iodide ions? (Ksp of AgBr = 5.4 × 10-13 and Ksp of AgI = 8.5 × 10-17)

Correct AnswerverifiedShow Answer

What is the pH of a buffer that results when 0.40 mol NaHCO2 is mixed with 100.0 mL of 2.00 M HCl(aq) and diluted with water to 250 mL? (Ka of HCO2H = 1.8 × 10-4)

Correct AnswerverifiedShow Answer

What is the concentration of Cd²⁺(aq) in a mixture of 0.014 mol Cd(NO₃) ₂ and 1.0 mol NH₃ diluted to 1.00 L? For Cd(NH₃) ₄²⁺, K_f = 1.0 × 10⁷.

Correct Answer
verified

Calculate the molar concentration of uncomplexed Zn²⁺(aq) in a solution that contains 0.17 M Zn(NH₃) ₄²⁺ and 0.3775 M NH₃ at equilibrium. K_f for Zn(NH₃) ₄²⁺ is $2.9 \times 10 ^ { 9 }$ .

Correct Answer
verified

A 1.0-liter solution contains 0.25 M HF and 0.33 M NaF (K_a for HF is 7.2 × 10^-4) . If one adds 0.30 liters of 0.020 M KOH to the solution, what will be the change in pH?

Correct Answer
verified

What is the pH of the buffer that results when 12.0 g of NaH₂PO₄ and 8.00 g of Na₂HPO₄ are diluted with water to a volume of 0.50 L? (K_a of H₂PO₄^- = 6.2 × 10^-8, the molar masses of NaH₂PO₄ and Na₂HPO₄ are 120.0 g/mol and 142.0 mol, respectively)

Correct Answer
verified

What mass of sodium hydroxide must be added to 65.0 mL of 0.926 M acetic acid in order to create a buffer with a pH of 4.83? K_a for acetic acid is 1.8 × 10^-5.

Correct Answer
verified

The K_sp of BaSO₄ is 1.1 × 10^-10 at 25 °C. What mass of BaSO₄ will dissolve in 1.0 L of water at 25 °C? (molar mass = 233.4 g/mol)

Correct Answer
verified

The concentration of Pb²⁺ in an aqueous solution is 5.5 × 10^-3 M. What concentration of SO₄^2- is required to begin precipitating PbSO₄? The K_sp of PbSO₄ is 2.5 × 10^-8.

Correct Answer
verified

The solubility of strontium carbonate (SrCO₃) in water at 25°C is $4.5 \times 10 ^ { - 3 }$ g/L. What is the K_sp of this sparingly soluble salt?

Correct Answer
verified

If 25 mL of 0.10 M NaOH is added to 40 mL of 0.20 M HC₂H₃O₂, what is the pH of the resulting solution at 25°C? K_a for HC₂H₃O₂ is 1.8 × 10^-5 at 25°C.

Correct Answer
verified

What is the molar solubility of Mn(OH) ₂(s) in a solution that is buffered at pH 8.00 at 25 °C? The K_sp of Mn(OH) ₂ is 1.9 × 10^-13 at 25 °C.

Correct Answer
verified

How many moles of solid NaF would have to be added to 1.0 L of 2.16 M HF solution to achieve a buffer of pH 3.35? Assume there is no volume change. (K_a for HF = 7.2 × 10^-4)

Correct Answer
verified

A volume of 25.0 mL of 0.100 M C₆H₅CO₂H(aq) is titrated with 0.100 M NaOH(aq) . What is the pH after the addition of 12.5 mL of NaOH? (K_a of benzoic acid = 6.3 × 10^-5)

Correct Answer
verified

A 50.00-mL solution of 0.0400 M hydrofluoric acid (K_a = 7.2 × 10^-4) is titrated with a 0.0153 M solution of NaOH as the titrant. What is the pH of at the equivalence point? (K_w = 1.00 × 10^-14)

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Why do salts containing basic anions have a greater solubility in water than predicted from calculations using K_sp values? Examples of such salts are CaCO₃, PbF₂, and Ca₃(PO₄)₂.

Correct Answer
verified
Basic anions react with water to form th...
View Answer

Correct Answer
verified

The K_sp of Ca(OH) ₂ is 5.5 × 10^-5 at 25 °C. What is the concentration of OH^-(aq) in a saturated solution of Ca(OH) ₂(aq) ?

Correct Answer
verified

Correct Answer
verified

What is the pH of a buffer that results when 0.40 mol NaHCO₂ is mixed with 100.0 mL of 2.00 M HCl(aq) and diluted with water to 250 mL? (K_a of HCO₂H = 1.8 × 10^-4)

Correct Answer
verified