Question 1

A solution is prepared by dissolving 0.23 mol of benzoic acid and 0.27 mol of sodium benzoate in water sufficient to yield 1.00 L of solution.The addition of 0.05 mol of HCl to this buffer solution causes the pH to drop slightly.The pH does not decrease drastically because the HCl reacts with the ________ present in the buffer solution.The Ka of benzoic acid is 1.36 × 10-3.

Accepted Answer

A) H2O 
B) H3O+ 
C) benzoate ion 
D) benzoic acid 
E) This is a buffer solution: the pH does not change upon addition of acid or base.

Question 2

When titrating a strong monoprotic acid and KOH at 25°C,the

Accepted Answer

A) pH will be less than 7 at the equivalence point. 
B) pH will be greater than 7 at the equivalence point. 
C) titration will require more moles of base than acid to reach the equivalence point. 
D) pH will be equal to 7 at the equivalence point. 
E) titration will require more moles of acid than base to reach the equivalence point.

Question 3

Match the following.
-pH > 7

Accepted Answer

A) half-way to equivalence point of a weak acid/strong base titration 
B) equivalence point of a strong acid/strong base titration 
C) equivalence point of a weak base/strong acid titration 
D) equivalence point of a weak acid/strong base titration

Question 4

A 100.0 mL sample of 0.20 M HF is titrated with 0.10 M KOH.Determine the pH of the solution before the addition of any KOH.The Ka of HF is 3.5 × 10-4.

Accepted Answer

A) 4.15 
B) 0.70 
C) 2.08 
D) 3.46 
E) 1.00

Question 5

A 25.0-mL sample of 0.150 M hydrazoic acid is titrated with a 0.150 M NaOH solution.What is the pH after 13.3 mL of base is added? 
The Ka of hydrazoic acid is 1.9 × 10-5.

Accepted Answer

A) 4.45 
B) 1.34 
C) 3.03 
D) 4.78 
E) 4.66

Question 6

A 100.0 mL sample of 0.10 M NH3 is titrated with 0.10 M HNO3.Determine the pH of the solution after the addition of 50.0 mL of HNO3.The Kb of NH3 is 1.8 × 10-5.

Accepted Answer

A) 4.74 
B) 7.78 
C) 7.05 
D) 9.26 
E) 10.34

Question 7

If the pKa of HCHO2 is 3.74 and the pH of an HCHO2/NaCHO2 solution is 3.11,which of the following is true?

Accepted Answer

A) [HCHO2] 2] 
B) [HCHO2] = [NaCHO2] 
C) [HCHO2] 2] 
D) [HCHO2] > [NaCHO2] 
E) It is not possible to make a buffer of this pH from HCHO2 and NaCHO2.

Question 8

A 100.0 mL sample of 0.10 M Ca(OH)2 is titrated with 0.10 M HBr.Determine the pH of the solution after the addition of 100.0 mL HBr.

Accepted Answer

A) 2.00 
B) 12.00 
C) 1.30 
D) 12.70 
E) 7.00

Question 9

Which of the following solutions is a good buffer system?

Accepted Answer

A) a solution that is 0.10 M NaCl and 0.10 M HCl 
B) a solution that is 0.10 M HCN and 0.10 M LiCN 
C) a solution that is 0.10 M LiOH and 0.10 M HNO3 
D) a solution that is 0.10 M HNO3 and 0.10 M LiNO3 
E) a solution that is 0.10 M HCN and 0.10 M KBr

Question 10

A 100.0 mL sample of 0.18 M HClO4 is titrated with 0.27 M LiOH.Determine the pH of the solution after the addition of 30.0 mL of LiOH.

Accepted Answer

A) 0.86 
B) 1.21 
C) 2.00 
D) 1.12 
E) 2.86

Question 11

What is the pH of a buffer solution that is 0.255 M in hypochlorous acid (HClO)and 0.333 M in sodium hypochlorite? The Ka of hypochlorous acid is 3.8 × 10-8.

Accepted Answer

A) 13.88 
B) 6.46 
C) 8.49 
D) 7.30 
E) 7.54

Question 12

Define a complex ion

Accepted Answer

The answer of Define a complex ion...

Question 13

What is the molar solubility of barium fluoride (BaF2)in water? The solubility-product constant for BaF2 is 1.7 × 10-6 at 25°C.

Accepted Answer

A) 6.5 × 10-4 
B) 1.2 × 10-2 
C) 1.8 × 10-3 
D) 7.5 × 10-3 
E) 5.7 × 10-7

Question 14

Calculate the pH of a buffer that is 0.058 M HF and 0.058 M LiF.The Ka for HF is 3.5 × 10-4.

Accepted Answer

A) 2.86 
B) 9.31 
C) 10.54 
D) 3.46 
E) 4.69

Question 15

Define buffer capacity.

Accepted Answer

A) Buffer capacity is the amount of acid or base that can be added to a buffer without destroying its effectiveness. 
B) Buffer capacity is the amount of acid that can be added until all of the base is used up. 
C) Buffer capacity is the amount of base that can be added until all of the acid is used up. 
D) Buffer capacity is the amount of acid that can be added until all of the acid is used up. 
E) Buffer capacity is the amount of base that can be added until all of the base is used up.

Question 16

An aqueous solution of 0.01 M NaCl and 0.01 M AgNO3 are mixed.Which statement is true?
(Ksp of AgCl = 1.8 × 10-10)

Accepted Answer

A) A precipitate of AgCl will form. 
B) No precipitate will form. 
C) The solution will not have any Ag+ and Cl- ions after precipitation. 
D) None of the above

Question 17

Calculate the percent ionization of nitrous acid in a solution that is 0.249 M in nitrous acid.The acid dissociation constant of nitrous acid is 4.50 × 10-4.

Accepted Answer

A) 1.12 × 10-4 
B) 0.0450 
C) 4.25 
D) 0.342 
E) 5.53

Question 18

Calculate the pH of a solution formed by mixing 250.0 mL of 0.15 M NH4Cl with 100.0 mL of
0.20 M NH3.The Kb for NH3 is 1.8 × 10-5.

Accepted Answer

A) 9.13 
B) 9.25 
C) 9.53 
D) 4.74 
E) 8.98

Question 19

What is the molar solubility of AgCl in 0.30 M NH3? Ksp for AgCl is 1.8 × 10-10 and Kf for Ag(NH3)2+ is 1.7 × 107.

Accepted Answer

A) 1.3 × 10-5 M 
B) 1.6 × 10-2 M 
C) 1.7 × 10-2 M 
D) 5.5 × 10-2 M

Question 20

Determine the molar solubility of Co3(AsO4)2 in pure water.Ksp (Co3(AsO4)2)= 6.80 × 10-29.

Accepted Answer

A) 2.02 × 10-5 
B) 2.32 × 10-6 
C) 2.15 × 10-8 
D) 9.26 × 10-6 
E) 9.12 × 10-7

Exam 16: Aqueous Ionic Equilibrium

When titrating a strong monoprotic acid and KOH at 25°C,the

Match the following. -pH > 7

A 100.0 mL sample of 0.20 M HF is titrated with 0.10 M KOH.Determine the pH of the solution before the addition of any KOH.The K_a of HF is 3.5 × 10^-4.

A 25.0-mL sample of 0.150 M hydrazoic acid is titrated with a 0.150 M NaOH solution.What is the pH after 13.3 mL of base is added? The K_a of hydrazoic acid is 1.9 × 10^-5.

A 100.0 mL sample of 0.10 M NH₃ is titrated with 0.10 M HNO₃.Determine the pH of the solution after the addition of 50.0 mL of HNO₃.The K_b of NH₃ is 1.8 × 10^-5.

If the pK_a of HCHO₂ is 3.74 and the pH of an HCHO₂/NaCHO₂solution is 3.11,which of the following is true?

A 100.0 mL sample of 0.10 M Ca(OH) ₂ is titrated with 0.10 M HBr.Determine the pH of the solution after the addition of 100.0 mL HBr.

Which of the following solutions is a good buffer system?

A 100.0 mL sample of 0.18 M HClO₄ is titrated with 0.27 M LiOH.Determine the pH of the solution after the addition of 30.0 mL of LiOH.

What is the pH of a buffer solution that is 0.255 M in hypochlorous acid (HClO) and 0.333 M in sodium hypochlorite? The K_a of hypochlorous acid is 3.8 × 10^-⁸.

Define a complex ion

What is the molar solubility of barium fluoride (BaF₂) in water? The solubility-product constant for BaF₂ is 1.7 × 10^-6 at 25°C.

Calculate the pH of a buffer that is 0.058 M HF and 0.058 M LiF.The K_a for HF is 3.5 × 10^-4.

Define buffer capacity.

An aqueous solution of 0.01 M NaCl and 0.01 M AgNO₃ are mixed.Which statement is true? (K_sp of AgCl = 1.8 × 10^-10)

Calculate the percent ionization of nitrous acid in a solution that is 0.249 M in nitrous acid.The acid dissociation constant of nitrous acid is 4.50 × 10^-4.

Calculate the pH of a solution formed by mixing 250.0 mL of 0.15 M NH₄Cl with 100.0 mL of 0.20 M NH₃.The K_b for NH₃ is 1.8 × 10^-5.

What is the molar solubility of AgCl in 0.30 M NH₃? K_sp for AgCl is 1.8 × 10^-10 and K_f for Ag(NH₃) ₂⁺ is 1.7 × 10⁷.

Determine the molar solubility of Co₃(AsO₄) ₂in pure water.K_sp (Co₃(AsO₄) ₂) = 6.80 × 10^-29.

Exam 16: Aqueous Ionic Equilibrium

When titrating a strong monoprotic acid and KOH at 25°C,the

Match the following. -pH > 7

A 100.0 mL sample of 0.20 M HF is titrated with 0.10 M KOH.Determine the pH of the solution before the addition of any KOH.The Ka of HF is 3.5 × 10-4.

A 25.0-mL sample of 0.150 M hydrazoic acid is titrated with a 0.150 M NaOH solution.What is the pH after 13.3 mL of base is added? The Ka of hydrazoic acid is 1.9 × 10-5.

A 100.0 mL sample of 0.10 M NH3 is titrated with 0.10 M HNO3.Determine the pH of the solution after the addition of 50.0 mL of HNO3.The Kb of NH3 is 1.8 × 10-5.

If the pKa of HCHO2 is 3.74 and the pH of an HCHO2/NaCHO2 solution is 3.11,which of the following is true?

A 100.0 mL sample of 0.10 M Ca(OH) 2 is titrated with 0.10 M HBr.Determine the pH of the solution after the addition of 100.0 mL HBr.

Which of the following solutions is a good buffer system?

A 100.0 mL sample of 0.18 M HClO4 is titrated with 0.27 M LiOH.Determine the pH of the solution after the addition of 30.0 mL of LiOH.

What is the pH of a buffer solution that is 0.255 M in hypochlorous acid (HClO) and 0.333 M in sodium hypochlorite? The Ka of hypochlorous acid is 3.8 × 10-8.

Define a complex ion

What is the molar solubility of barium fluoride (BaF2) in water? The solubility-product constant for BaF2 is 1.7 × 10-6 at 25°C.

Calculate the pH of a buffer that is 0.058 M HF and 0.058 M LiF.The Ka for HF is 3.5 × 10-4.

Define buffer capacity.

An aqueous solution of 0.01 M NaCl and 0.01 M AgNO3 are mixed.Which statement is true? (Ksp of AgCl = 1.8 × 10-10)

Calculate the percent ionization of nitrous acid in a solution that is 0.249 M in nitrous acid.The acid dissociation constant of nitrous acid is 4.50 × 10-4.

Calculate the pH of a solution formed by mixing 250.0 mL of 0.15 M NH4Cl with 100.0 mL of 0.20 M NH3.The Kb for NH3 is 1.8 × 10-5.

What is the molar solubility of AgCl in 0.30 M NH3? Ksp for AgCl is 1.8 × 10-10 and Kf for Ag(NH3) 2+ is 1.7 × 107.

Determine the molar solubility of Co3(AsO4) 2 in pure water.Ksp (Co3(AsO4) 2) = 6.80 × 10-29.

A 100.0 mL sample of 0.20 M HF is titrated with 0.10 M KOH.Determine the pH of the solution before the addition of any KOH.The K_a of HF is 3.5 × 10^-4.

A 25.0-mL sample of 0.150 M hydrazoic acid is titrated with a 0.150 M NaOH solution.What is the pH after 13.3 mL of base is added? The K_a of hydrazoic acid is 1.9 × 10^-5.

A 100.0 mL sample of 0.10 M NH₃ is titrated with 0.10 M HNO₃.Determine the pH of the solution after the addition of 50.0 mL of HNO₃.The K_b of NH₃ is 1.8 × 10^-5.

If the pK_a of HCHO₂ is 3.74 and the pH of an HCHO₂/NaCHO₂solution is 3.11,which of the following is true?

A 100.0 mL sample of 0.10 M Ca(OH) ₂ is titrated with 0.10 M HBr.Determine the pH of the solution after the addition of 100.0 mL HBr.

A 100.0 mL sample of 0.18 M HClO₄ is titrated with 0.27 M LiOH.Determine the pH of the solution after the addition of 30.0 mL of LiOH.

What is the pH of a buffer solution that is 0.255 M in hypochlorous acid (HClO) and 0.333 M in sodium hypochlorite? The K_a of hypochlorous acid is 3.8 × 10^-⁸.

What is the molar solubility of barium fluoride (BaF₂) in water? The solubility-product constant for BaF₂ is 1.7 × 10^-6 at 25°C.

Calculate the pH of a buffer that is 0.058 M HF and 0.058 M LiF.The K_a for HF is 3.5 × 10^-4.

An aqueous solution of 0.01 M NaCl and 0.01 M AgNO₃ are mixed.Which statement is true? (K_sp of AgCl = 1.8 × 10^-10)

Calculate the percent ionization of nitrous acid in a solution that is 0.249 M in nitrous acid.The acid dissociation constant of nitrous acid is 4.50 × 10^-4.

Calculate the pH of a solution formed by mixing 250.0 mL of 0.15 M NH₄Cl with 100.0 mL of 0.20 M NH₃.The K_b for NH₃ is 1.8 × 10^-5.

What is the molar solubility of AgCl in 0.30 M NH₃? K_sp for AgCl is 1.8 × 10^-10 and K_f for Ag(NH₃) ₂⁺ is 1.7 × 10⁷.

Determine the molar solubility of Co₃(AsO₄) ₂in pure water.K_sp (Co₃(AsO₄) ₂) = 6.80 × 10^-29.