Question 1

If the pKa of HCHO2 is 3.74 and the pH of an HCHO2/NaCHO2 solution is 3.89,which of the following is TRUE?

Accepted Answer

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

Question 2

A sample contains MgNH4(PO4)2, Sb2S3,KBr,Cr(OH)3,and PbCl2.Identify the precipitate after the addition of 6 M HCl; then H2S and 0.2 M HCl.

Accepted Answer

A)  MgNH4(PO4)2 
B)  Sb2S3 
C)  KBr 
D)  Cr(OH)3 
E)  PbCl2 
A)  MgNH4(PO4)2 
B)  Sb2S3 
C)  KBr 
D)  Cr(OH)3 
E)  PbCl2

Question 3

Calculate the percent ionization of nitrous acid in a solution that is 0.222 M in nitrous acid (HNO2)and 0.278 M in potassium nitrite (KNO2).The acid dissociation constant of nitrous acid is 4.50 × 10-4.

Accepted Answer

A)  55.6 
B)  0.162 
C)  15.5 
D)  2.78 × 10-3 
E)  3.448 
A)  55.6 
B)  0.162 
C)  15.5 
D)  2.78 × 10-3 
E)  3.448

Question 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 26.0 mL of base is added? The Ka of hydrazoic acid is 1.9 × 10-5.

Accepted Answer

A)  2.54 
B)  11.47 
C)  7.00 
D)  4.70 
E)  4.74 
A)  2.54 
B)  11.47 
C)  7.00 
D)  4.70 
E)  4.74

Question 5

Determine the molar solubility of MgCO3 in pure water.Ksp (MgCO3)= 6.82 × 10-6.

Accepted Answer

A)  6.82 × 10-6 M 
B)  3.41 × 10-6 M 
C)  4.65 × 10-3 M 
D)  2.61 × 10-3 M 
E)  3.25 × 10-4 M 
A)  6.82 × 10-6 M 
B)  3.41 × 10-6 M 
C)  4.65 × 10-3 M 
D)  2.61 × 10-3 M 
E)  3.25 × 10-4 M

Question 6

Give the equation for a supersaturated solution in comparing Q with Ksp.

Accepted Answer

A)  Q > Ksp 
B)  Q sp 
C)  Q = Ksp 
D)  Q ≠ Ksp 
E)  none of the above 
A)  Q > Ksp 
B)  Q sp 
C)  Q = Ksp 
D)  Q ≠ Ksp 
E)  none of the above

Question 7

What is the pH of the resulting solution if 35.00 mL of 0.10 M acetic acid is added to 10.00 mL of 0.10 M KOH? Assume that the volumes of the solutions are additive.Ka = 1.8 × 10-5 for CH3CO2H

Accepted Answer

A)  9.65 
B)  8.86 
C)  5.14 
D)  4.35 
E)  6.62 
A)  9.65 
B)  8.86 
C)  5.14 
D)  4.35 
E)  6.62

Question 8

Identify the most common indicator.

Accepted Answer

A)  alizarin 
B)  thymol blue 
C)  crystal violet 
D)  phenolphthalein 
E)  thymolphthalein 
A)  alizarin 
B)  thymol blue 
C)  crystal violet 
D)  phenolphthalein 
E)  thymolphthalein

Question 9

What is the pH of a solution made by mixing 15.00 mL of 0.100 M HCl with 50.00 mL of 0.100 M KOH? Assume that the volumes of the solutions are additive.

Accepted Answer

A)  11.73 
B)  12.73 
C)  1.27 
D)  2.27 
E)  7.00 
A)  11.73 
B)  12.73 
C)  1.27 
D)  2.27 
E)  7.00

Question 10

A solution is prepared by dissolving 0.23 mol of hydrazoic acid and 0.27 mol of sodium azide in water sufficient to yield 1.00 L of solution.The addition of 0.05 mol of NaOH to this buffer solution causes the pH to increase slightly.The pH does not increase drastically because the NaOH reacts with the ________ present in the buffer solution.The Ka of hydrazoic acid is 1.9 × 10-5.

Accepted Answer

A)    O 
B)    
C)  azide 
D)  hydrazoic acid 
E)  This is a buffer solution: the pH does not change upon addition of acid or base. 
A)    O 
B)    
C)  azide 
D)  hydrazoic acid 
E)  This is a buffer solution: the pH does not change upon addition of acid or base.

Question 11

A sample contains MgNH4(PO4)2, Sb2S3,KBr,Cr(OH)3,and PbCl2.Identify the precipitate after the addition of 6 M HCl; then H2S and 0.2 M HCl; then OH- to a pH of 8; and then (NH4)2HPO4 with NH3.

Accepted Answer

A)  MgNH4(PO4)2 
B)  Sb2S3 
C)  KBr 
D)  Cr(OH)3 
E)  PbCl2 
A)  MgNH4(PO4)2 
B)  Sb2S3 
C)  KBr 
D)  Cr(OH)3 
E)  PbCl2

Question 12

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. 
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 13

Describe what happens at low pH for aluminum hydroxide.

Accepted Answer

A)  Al(H2O)63+ dissolves. 
B)  Al(H2O)4(OH)2- precipitates. 
C)  Al(OH)3 precipitates. 
D)  Al precipitates. 
E)  Al dissolves. 
A)  Al(H2O)63+ dissolves. 
B)  Al(H2O)4(OH)2- precipitates. 
C)  Al(OH)3 precipitates. 
D)  Al precipitates. 
E)  Al dissolves.

Question 14

Identify the ion that is less soluble in acidic water.

Accepted Answer

A)  NH4+ 
B)  S2- 
C)  CO32- 
D)  OH- 
E)  CN- 
A)  NH4+ 
B)  S2- 
C)  CO32- 
D)  OH- 
E)  CN-

Question 15

The molar solubility of Ba3(PO4)2 is 8.89 × 10-9 M in pure water.Calculate the Ksp for Ba3(PO4)2.

Accepted Answer

A)  4.94 × 10-49 M 
B)  5.55 × 10-41 M 
C)  5.33 × 10-37 M 
D)  8.16 × 10-31 M 
E)  6.00 × 10-39 M  
A)  4.94 × 10-49 M 
B)  5.55 × 10-41 M 
C)  5.33 × 10-37 M 
D)  8.16 × 10-31 M 
E)  6.00 × 10-39 M

Question 16

A 600.0 mL sample of 0.20 M HF is titrated with 0.10 M NaOH.Determine the pH of the solution after the addition of 600.0 mL of NaOH.The Ka of HF is 3.5 × 10-4.

Accepted Answer

A)  2.08 
B)  3.15 
C)  4.33 
D)  3.46 
E)  4.15 
A)  2.08 
B)  3.15 
C)  4.33 
D)  3.46 
E)  4.15

Question 17

Give the name of the compound that is in antifreeze and is toxic to pets.

Accepted Answer

The answer of Give the name of the compound that...

Question 18

A 100.0 mL sample of 0.20 M HF is titrated with 0.10 M KOH.Determine the pH of the solution after the addition of 300.0 mL of KOH.The Ka of HF is 3.5 × 10-4.

Accepted Answer

A)  12.40 
B)  9.33 
C)  7.00 
D)  8.94 
E)  12.00 
A)  12.40 
B)  9.33 
C)  7.00 
D)  8.94 
E)  12.00

Question 19

Determine the molar solubility of CuCl in a solution containing 0.020 M LiCl. Ksp (CuCl)= 1.0 × 10-6.

Accepted Answer

A)  1.0 × 10-12 M 
B)  2.0 × 10-8 M 
C)  5.0 × 10-5 M 
D)  1.0 × 10-3 M 
E)  0.20 M 
A)  1.0 × 10-12 M 
B)  2.0 × 10-8 M 
C)  5.0 × 10-5 M 
D)  1.0 × 10-3 M 
E)  0.20 M

Question 20

Identify the compound that is in stalactites and stalagmites.

Accepted Answer

The answer of Identify the compound that is in stalactites...

Exam 17: Aqueous Ionic Equilibrium

If the pKa of HCHO2 is 3.74 and the pH of an HCHO2/NaCHO2 solution is 3.89,which of the following is TRUE?

A sample contains MgNH4(PO4)2, Sb2S3,KBr,Cr(OH)3,and PbCl2.Identify the precipitate after the addition of 6 M HCl; then H2S and 0.2 M HCl.

Calculate the percent ionization of nitrous acid in a solution that is 0.222 M in nitrous acid (HNO2)and 0.278 M in potassium nitrite (KNO2).The acid dissociation constant of nitrous acid is 4.50 × 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 26.0 mL of base is added? The Ka of hydrazoic acid is 1.9 × 10-5.

Determine the molar solubility of MgCO3 in pure water.Ksp (MgCO3)= 6.82 × 10-6.

Give the equation for a supersaturated solution in comparing Q with Ksp.

What is the pH of the resulting solution if 35.00 mL of 0.10 M acetic acid is added to 10.00 mL of 0.10 M KOH? Assume that the volumes of the solutions are additive.Ka = 1.8 × 10-5 for CH3CO2H

Identify the most common indicator.

What is the pH of a solution made by mixing 15.00 mL of 0.100 M HCl with 50.00 mL of 0.100 M KOH? Assume that the volumes of the solutions are additive.

A sample contains MgNH4(PO4)2, Sb2S3,KBr,Cr(OH)3,and PbCl2.Identify the precipitate after the addition of 6 M HCl; then H2S and 0.2 M HCl; then OH- to a pH of 8; and then (NH4)2HPO4 with NH3.

Define buffer capacity.

Describe what happens at low pH for aluminum hydroxide.

Identify the ion that is less soluble in acidic water.

The molar solubility of Ba3(PO4)2 is 8.89 × 10-9 M in pure water.Calculate the Ksp for Ba3(PO4)2.

A 600.0 mL sample of 0.20 M HF is titrated with 0.10 M NaOH.Determine the pH of the solution after the addition of 600.0 mL of NaOH.The Ka of HF is 3.5 × 10-4.

Give the name of the compound that is in antifreeze and is toxic to pets.

A 100.0 mL sample of 0.20 M HF is titrated with 0.10 M KOH.Determine the pH of the solution after the addition of 300.0 mL of KOH.The Ka of HF is 3.5 × 10-4.

Determine the molar solubility of CuCl in a solution containing 0.020 M LiCl. Ksp (CuCl)= 1.0 × 10-6.

Identify the compound that is in stalactites and stalagmites.

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If the pKa of HCHO₂ is 3.74 and the pH of an HCHO₂/NaCHO₂solution is 3.89,which of the following is TRUE?

A sample contains MgNH₄(PO₄)₂,Sb₂S₃,KBr,Cr(OH)₃,and PbCl₂.Identify the precipitate after the addition of 6 M HCl; then H₂S and 0.2 M HCl.

Calculate the percent ionization of nitrous acid in a solution that is 0.222 M in nitrous acid (HNO₂)and 0.278 M in potassium nitrite (KNO₂).The acid dissociation constant of nitrous acid is 4.50 × 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 26.0 mL of base is added? The K_a of hydrazoic acid is 1.9 × 10^-5.

Determine the molar solubility of MgCO₃in pure water.K_sp (MgCO₃)= 6.82 × 10^-6.

Give the equation for a supersaturated solution in comparing Q with K_sp.

What is the pH of the resulting solution if 35.00 mL of 0.10 M acetic acid is added to 10.00 mL of 0.10 M KOH? Assume that the volumes of the solutions are additive.K_a = 1.8 × 10^-5for CH₃CO₂H

A sample contains MgNH₄(PO₄)₂,Sb₂S₃,KBr,Cr(OH)₃,and PbCl₂.Identify the precipitate after the addition of 6 M HCl; then H₂S and 0.2 M HCl; then OH^-to a pH of 8; and then (NH₄)₂HPO₄ with NH₃.

The molar solubility of Ba₃(PO₄)₂ is 8.89 × 10^-9M in pure water.Calculate the K_sp for Ba₃(PO₄)₂.

A 600.0 mL sample of 0.20 M HF is titrated with 0.10 M NaOH.Determine the pH of the solution after the addition of 600.0 mL of NaOH.The K_a of HF is 3.5 × 10^-4.

A 100.0 mL sample of 0.20 M HF is titrated with 0.10 M KOH.Determine the pH of the solution after the addition of 300.0 mL of KOH.The K_a of HF is 3.5 × 10^-4.

Determine the molar solubility of CuCl in a solution containing 0.020 M LiCl. K_sp (CuCl)= 1.0 × 10^-6.