Question 1

What is the effect on equilibrium when sodium acetate is added to a solution of acetic acid? CH3COOH(aq)   H+(aq) + CH3COO-(aq)

Accepted Answer

A)  There is no change in the equilibrium. 
B)  The equilibrium shifts to the right. 
C)  More information is needed to answer the question. 
D)  The equilibrium shifts to the left. 
E)  The pH decreases. 
A)  There is no change in the equilibrium. 
B)  The equilibrium shifts to the right. 
C)  More information is needed to answer the question. 
D)  The equilibrium shifts to the left. 
E)  The pH decreases.

Question 2

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

Accepted Answer

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

Question 3

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 the pKb of the conjugate base. 
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 conjugate base.

Question 4

Calculate the pH of a buffer solution prepared by dissolving 0.20 mole of sodium cyanate (NaCNO) and 1.0 mole of cyanic acid (HCNO) in enough water to make 1.0 liter of solution. [Ka(HCNO) = 2.0 × 10-4]

Accepted Answer

A)  0.00 
B)  3.00 
C)  3.70 
D)  4.40 
E)  5.00 
A)  0.00 
B)  3.00 
C)  3.70 
D)  4.40 
E)  5.00

Question 5

The ________ is the solution that is added from the buret during a titration.

Accepted Answer

The answer of The ________ is the solution that is...

Question 6

Suppose 50.0 mL of a 0.100 M solution of the weak acid HA is titrated with a 0.100 M solution of NaOH. Which diagram best represents the equilibrium composition of the solution once 25.0 mL of titrant have been added? (Solvent water molecules are omitted for clarity.)

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 7

Consider the dissolution of MnS in water. [Ksp(MnS) =3.0 × 10-14] MnS(s) + H2O(l)   Mn2+(aq) + HS-(aq) + OH-(aq)
How is the solubility of manganese(II) sulfide affected by the addition of aqueous potassium hydroxide to the system?

Accepted Answer

A)  The solubility will be unchanged. 
B)  The solubility will decrease. 
C)  The solubility will increase. 
D)  The amount of KOH added must be known before its effect can be predicted. 
E)  The pKa of H2S is needed before a reliable prediction can be made. 
A)  The solubility will be unchanged. 
B)  The solubility will decrease. 
C)  The solubility will increase. 
D)  The amount of KOH added must be known before its effect can be predicted. 
E)  The pKa of H2S is needed before a reliable prediction can be made.

Question 8

Below is a representation of the sparingly soluble salt MX at equilibrium in aqueous solution. (Each circle represents 1.0 ×10-3 mol of atoms, and the volume of the box is 1.0 L. Solvent water molecules are omitted for clarity.)   What is Ksp for MX?

Accepted Answer

A)  1.5 ×10-5 
B)  6.0 ×10-6 
C)  3.6 ×10-1 
D)  1.8 ×10-3 
E)  9.0 ×10-6 
A)  1.5 ×10-5 
B)  6.0 ×10-6 
C)  3.6 ×10-1 
D)  1.8 ×10-3 
E)  9.0 ×10-6

Question 9

What is the pH at the equivalence point in the titration of 100 mL of 0.10 M HCl with 0.10 M NaOH?

Accepted Answer

A)  1.0 
B)  6.0 
C)  7.0 
D)  8.0 
E)  13.0 
A)  1.0 
B)  6.0 
C)  7.0 
D)  8.0 
E)  13.0

Question 10

For the 1:1 ratio combination of a monoprotic strong acid and a monoprotic strong base, the ________ is where equal molar amounts of the strong acid and strong base have been combined.

Accepted Answer

The answer of For the 1:1 ratio combination of a...

Question 11

What is the Henderson-Hasselbach equation?

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 12

A 50.00-mL solution of 0.10 M HNO2 is titrated with a 0.10 M KOH solution. After 25.00 mL of the KOH solution is added, what is the pH in the titration flask? [Ka(HNO2) = 4.5 × 10-4]

Accepted Answer

A)  2.17 
B)  3.35 
C)  2.41 
D)  1.48 
E)  7.00 
A)  2.17 
B)  3.35 
C)  2.41 
D)  1.48 
E)  7.00

Question 13

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

Accepted Answer

A) True 
 B)False

Question 14

What is the [H3O+] in a solution that consists of 1.5 M NH3 and 2.5 M 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)  5.6 × 10-10 M 
E)  9.3 × 10-10 M 
A)  1.1 × 10-5 M 
B)  3.0 × 10-6 M 
C)  3.3 × 10-9 M 
D)  5.6 × 10-10 M 
E)  9.3 × 10-10 M

Question 15

Which one of the following is the best representation of the titration curve which will be obtained in the titration of a weak diprotic acid H2A (0.10 M) with a strong base of the same concentration?

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 16

You have 500.0 mL of a buffer solution containing 0.20 M acetic acid (CH3COOH) and 0.30 M sodium acetate (CH3COONa). What will the pH of this solution be after the addition of 20.0 mL of 1.00 M NaOH solution? [Ka(CH3COOH) = 1.8 × 10-5]

Accepted Answer

A)  4.41 
B)  4.74 
C)  4.56 
D)  4.92 
E)  5.07 
A)  4.41 
B)  4.74 
C)  4.56 
D)  4.92 
E)  5.07

Question 17

The indicator propyl red has Ka = 3.3 × 10-6. What would be the approximate pH range over which it would change color?

Accepted Answer

A)  3.5 - 5.5 
B)  4.5 - 6.5 
C)  5.5 - 7.5 
D)  6.5 - 8.5 
E)  7.5 - 9.5 
A)  3.5 - 5.5 
B)  4.5 - 6.5 
C)  5.5 - 7.5 
D)  6.5 - 8.5 
E)  7.5 - 9.5

Question 18

Suppose 0.015 mol of KOH is added to 1.00 L of 0.0010 M Ca(NO3)2. Which statement is correct? [Ksp(Ca(OH)2) = 6.5 × 10-6]

Accepted Answer

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)  Potassium nitrate precipitates until the solution is saturated. 
E)  The presence of KOH will raise the solubility of Ca(NO3)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)  Potassium nitrate precipitates until the solution is saturated. 
E)  The presence of KOH will raise the solubility of Ca(NO3)2.

Question 19

Calculate the minimum concentration of Mg2+ that must be added to 0.10 M NaF in order to initiate a precipitate of magnesium fluoride. [Ksp(MgF2) = 6.9 × 10-9]

Accepted Answer

A)  1.4 × 107 M 
B)  6.9 × 10-9 M 
C)  6.9 × 10-8 M 
D)  1.7 × 10-7 M 
E)  6.9 × 10-7 M 
A)  1.4 × 107 M 
B)  6.9 × 10-9 M 
C)  6.9 × 10-8 M 
D)  1.7 × 10-7 M 
E)  6.9 × 10-7 M

Question 20

A CH3COOH/CH3COO- buffer can be produced by adding a strong acid to a solution of CH3COO- ions.

Accepted Answer

A) True 
 B)False

Exam 17: Acid-Base Equilibria and Solubility Equilibria

What is the effect on equilibrium when sodium acetate is added to a solution of acetic acid? CH3COOH(aq) H+(aq) + CH3COO-(aq)

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

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

Calculate the pH of a buffer solution prepared by dissolving 0.20 mole of sodium cyanate (NaCNO) and 1.0 mole of cyanic acid (HCNO) in enough water to make 1.0 liter of solution. [Ka(HCNO) = 2.0 × 10-4]

The ________ is the solution that is added from the buret during a titration.

Suppose 50.0 mL of a 0.100 M solution of the weak acid HA is titrated with a 0.100 M solution of NaOH. Which diagram best represents the equilibrium composition of the solution once 25.0 mL of titrant have been added? (Solvent water molecules are omitted for clarity.)

Consider the dissolution of MnS in water. [Ksp(MnS) =3.0 × 10-14] MnS(s) + H2O(l) Mn2+(aq) + HS-(aq) + OH-(aq) How is the solubility of manganese(II) sulfide affected by the addition of aqueous potassium hydroxide to the system?

Below is a representation of the sparingly soluble salt MX at equilibrium in aqueous solution. (Each circle represents 1.0 ×10-3 mol of atoms, and the volume of the box is 1.0 L. Solvent water molecules are omitted for clarity.) What is Ksp for MX?

What is the pH at the equivalence point in the titration of 100 mL of 0.10 M HCl with 0.10 M NaOH?

For the 1:1 ratio combination of a monoprotic strong acid and a monoprotic strong base, the ________ is where equal molar amounts of the strong acid and strong base have been combined.

What is the Henderson-Hasselbach equation?

A 50.00-mL solution of 0.10 M HNO2 is titrated with a 0.10 M KOH solution. After 25.00 mL of the KOH solution is added, what is the pH in the titration flask? [Ka(HNO2) = 4.5 × 10-4]

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

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

Which one of the following is the best representation of the titration curve which will be obtained in the titration of a weak diprotic acid H2A (0.10 M) with a strong base of the same concentration?

You have 500.0 mL of a buffer solution containing 0.20 M acetic acid (CH3COOH) and 0.30 M sodium acetate (CH3COONa). What will the pH of this solution be after the addition of 20.0 mL of 1.00 M NaOH solution? [Ka(CH3COOH) = 1.8 × 10-5]

The indicator propyl red has Ka = 3.3 × 10-6. What would be the approximate pH range over which it would change color?

Suppose 0.015 mol of KOH is added to 1.00 L of 0.0010 M Ca(NO3)2. Which statement is correct? [Ksp(Ca(OH)2) = 6.5 × 10-6]

Calculate the minimum concentration of Mg2+ that must be added to 0.10 M NaF in order to initiate a precipitate of magnesium fluoride. [Ksp(MgF2) = 6.9 × 10-9]

A CH3COOH/CH3COO- buffer can be produced by adding a strong acid to a solution of CH3COO- ions.

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What is the effect on equilibrium when sodium acetate is added to a solution of acetic acid? CH₃COOH(aq) H⁺(aq) + CH₃COO^-(aq)

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

Calculate the pH of a buffer solution prepared by dissolving 0.20 mole of sodium cyanate (NaCNO) and 1.0 mole of cyanic acid (HCNO) in enough water to make 1.0 liter of solution. [K_a(HCNO) = 2.0 × 10^-4]

Consider the dissolution of MnS in water. [K_sp(MnS) =3.0 × 10^-14] MnS(s) + H₂O(l) Mn²⁺(aq) + HS^-(aq) + OH^-(aq) How is the solubility of manganese(II) sulfide affected by the addition of aqueous potassium hydroxide to the system?

Below is a representation of the sparingly soluble salt MX at equilibrium in aqueous solution. (Each circle represents 1.0 ×10^-3 mol of atoms, and the volume of the box is 1.0 L. Solvent water molecules are omitted for clarity.) What is K_sp for MX?

A 50.00-mL solution of 0.10 M HNO₂ is titrated with a 0.10 M KOH solution. After 25.00 mL of the KOH solution is added, what is the pH in the titration flask? [K_a(HNO₂) = 4.5 × 10^-4]

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

Which one of the following is the best representation of the titration curve which will be obtained in the titration of a weak diprotic acid H₂A (0.10 M) with a strong base of the same concentration?

You have 500.0 mL of a buffer solution containing 0.20 M acetic acid (CH₃COOH) and 0.30 M sodium acetate (CH₃COONa). What will the pH of this solution be after the addition of 20.0 mL of 1.00 M NaOH solution? [K_a(CH₃COOH) = 1.8 × 10^-5]

The indicator propyl red has K_a = 3.3 × 10^-6. What would be the approximate pH range over which it would change color?

Suppose 0.015 mol of KOH is added to 1.00 L of 0.0010 M Ca(NO₃)₂. Which statement is correct? [K_sp(Ca(OH)₂) = 6.5 × 10^-6]

Calculate the minimum concentration of Mg²⁺ that must be added to 0.10 M NaF in order to initiate a precipitate of magnesium fluoride. [K_sp(MgF₂) = 6.9 × 10^-9]

A CH₃COOH/CH₃COO^- buffer can be produced by adding a strong acid to a solution of CH₃COO^- ions.