Question 1

The following pictures represent solutions that contain a weak acid HA and/or its potassium salt KA.Unshaded spheres represent H atoms and shaded spheres represent AS1U1P1-S1S1P0 ions.(KS1U1P1+S1S1P0,HS1U1B13S1U1B0OS1U1P1+S1S1P0,OHS1U1P1-S1S1P0,and solvent HS1U1B12S1U1B0O molecules have been omitted for clarity. ) 
-Which of the solutions are buffer solutions?

Accepted Answer

A) (1)and (2) 
B) (1)and (3) 
C) (2)and (3) 
D) (2)and (4)

Question 2

What is the Henderson-Hasselbalch equation for the acidic buffer HA/A-?

Accepted Answer

A) pH = -log[H3O+] 
B) pH = 14 - pOH 
C) pH = pKa + log{[A-]/[HA]} 
D) pH = pKa - log{[A-]/[HA]}

Question 3

What is the pH of the solution formed when 50 mL of 0.250 M NaOH is added to 50 mL of 0.120 M HCl?

Accepted Answer

The answer of What is the pH of the solution...

Question 4

The following pictures represent solutions of AgCl,which may also contain ions other than AgS1U1P1+S1S1P0 and ClS1U1P1-S1S1P0 which are not shown.Gray spheres represent AgS1U1P1+S1S1P0 ions and dotted spheres represent ClS1U1P1-S1S1P0 ions. 
-If solution (1)is a saturated solution of AgCl,which of solutions (1)-(4)represents the solution after a small amount of NH3 is added and equilibrium is restored?

Accepted Answer

A) (1) 
B) (2) 
C) (3) 
D) (4)

Question 5

TRIS {(HOCH2)3CNH2} is one of the most common buffers used in biochemistry.A solution is prepared by adding enough TRIS and 12 M HCl(aq)to give 1.00 L of solution with [TRIS] = 0.30 M and [TRISH+] = 0.60 M.What is the pH of this buffered system if the pKb is 5.92?

Accepted Answer

A) 5)92 
B) 6)22 
C) 7)78 
D) 8)08

Question 6

What is the K_a of the amino acid glycine if it is 75.0% dissociated at pH = 10.08?

Accepted Answer

The answer of What is the K_a of the amino...

Question 7

What is the [CH3CO2-]/[CH3CO2H] ratio necessary to make a buffer solution with a pH of 4.44? Ka = 1.8 × 10-5 for CH3CO2H.

Accepted Answer

A) 0)50:1 
B) 0)94:1 
C) 1)1:1 
D) 2)0:1

Question 8

When 50 mL of 0.10 M NaF is added to 50 mL of 0.10 M HF,relative to the pH of the 0.10 M HF solution the pH of the resulting solution will

Accepted Answer

A) become 7. 
B) decrease. 
C) increase. 
D) remain the same.

Question 9

Calculate the Ksp for silver sulfite if the solubility of Ag2SO3 in pure water is 4.6 × 10-3 g/L.

Accepted Answer

A) 3)8 × 10-15 
B) 1)5 × 10-14 
C) 2)4 × 10-10 
D) 4)8 × 10-10

Question 10

Calculate the molar solubility of thallium(I)chloride in 0.40 M NaCl at 25°C.Ksp for TlCl is
1)7 × 10-4.

Accepted Answer

A) 6)8 × 10-5 M 
B) 4)2 × 10- 4 M 
C) 8)2 × 10-3 M 
D) 1)3 × 10-2 M

Question 11

The following pictures represent solutions that contain a weak acid HA (pKS1U1B1aS1U1B0 = 5.0)and its potassium salt KA.Unshaded spheres represent H atoms and shaded spheres represent AS1U1P1-S1S1P0 ions.(KS1U1P1+S1S1P0,HS1U1B13S1U1B0OS1U1P1+S1S1P0,OHS1U1P1-S1S1P0,and solvent HS1U1B12S1U1B0O molecules have been omitted for clarity. ) 
-Which solution has the greatest buffer capacity?

Accepted Answer

A) (1) 
B) (2) 
C) (3) 
D) (4)

Question 12

The following pictures represent solutions at various stages in the titration of a weak diprotic acid HS1U1B12S1U1B0A with aqueous KOH.Unshaded spheres represent H atoms,black spheres represent oxygen atoms,and shaded spheres represent AS1U1P12-S1S1P0 ions.(KS1U1P1+S1S1P0,HS1U1B13S1U1B0OS1U1P1+S1S1P0 initially present,OHS1U1P1-S1S1P0 initially present and solvent water molecules have been omitted for clarity). 
-Which picture represents the system halfway between the first and second equivalence points?

Accepted Answer

A) (1) 
B) (2) 
C) (3) 
D) (4)

Question 13

Which is a net ionic equation for the neutralization reaction of a weak acid with a weak base?

Accepted Answer

A) H3O+(aq)+ OH-(aq)⇌ 2 H2O(l) 
B) HF(aq)+ NH3(aq)⇌ NH4+(aq)+ F-(aq) 
C) HF(aq)+ OH-(aq)⇌ H2O(l)+ F-(aq) 
D) H3O+(aq)+ NH3(aq)⇌ NH4+(aq)+ H2O(l)

Question 14

Which of these neutralization reactions has a pH < 7 when equal molar amounts of acid and base are mixed?

Accepted Answer

A) CH3CO2H(aq)+ NaOH(aq)⇌ H2O(l)+ NaCH3CO2(aq) 
B) HCl(aq)+ C5H5N(aq)⇌ C5H5NHCl(aq) 
C) HCl(aq)+ NaOH(aq)⇌ H2O(l)+ NaCl(aq) 
D) H2SO4(aq)+ 2 KOH(aq)⇌2 H2O(l)+ K2SO4(aq)

Question 15

A solution may contain the following ions Ag+,Cu2+,Cd2+,Mn2+,Ni2+ and Na+.A white precipitate formed when 0.10 M NaCl was added and after this was removed the solution was treated with H2S gas under acidic conditions and no precipitate formed.When the solution was made basic and again treated with H2S gas a dark colored precipitate formed.If no further tests were made then what conclusions can you draw?

Accepted Answer

A) possible ions present Ag+,Mn2+,Ni2+ 
B) possible ions present Ag+,Mn2+,Ni2+,Na+ 
C) possible ions present Ag+,Cu2+,Cd2+ 
D) possible ions present Ag+,Cu2+,Cd2+,Na+

Question 16

What is the pH at the equivalence point of a weak base-strong acid titration if 20.00 mL of NaOCl requires 28.30 mL of 0.50 M HCl? Ka = 3.0 × 10-8 for HOCl.

Accepted Answer

A) 0)30 
B) 3)18 
C) 3)76 
D) 4)03

Question 17

What is the pH of a buffer solution made by mixing 50.0 mL of 0.100 M potassium hydrogen phthalate with 13.6 mL of 0.100 M NaOH and diluting the mixture to 100.0 mL with water? The Ka2 for hydrogen phthalate is 3.1 × 10-6.

Accepted Answer

A) 3)25 
B) 5)08 
C) 5)51 
D) 5)94

Question 18

What is the pH of a solution made by mixing 10.00 mL of 0.10 M acetic acid with 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) 5)28 
B) 7)00 
C) 8)72 
D) 10.02

Question 19

The following pictures represent solutions that contain a weak acid HA and/or its potassium salt KA.Unshaded spheres represent H atoms and shaded spheres represent AS1U1P1-S1S1P0 ions.(KS1U1P1+S1S1P0,HS1U1B13S1U1B0OS1U1P1+S1S1P0,OHS1U1P1-S1S1P0,and solvent HS1U1B12S1U1B0O molecules have been omitted for clarity. ) 
-Which solution has the highest pH?

Accepted Answer

A) (1) 
B) (2) 
C) (3) 
D) (4)

Question 20

The following plot shows two titration curves,each representing the titration of 50.00 mL of 0.100 M acid with 0.100 M NaOH. 
-Which points a-d represent the half-equivalence point and the equivalence point,respectively,for the titration of a weak acid?

Accepted Answer

A) points a and b 
B) points a and c 
C) points b and d 
D) points c and d

Exam 15: Applications of Aqueous Equilibria

The following pictures represent solutions that contain a weak acid HA and/or its potassium salt KA.Unshaded spheres represent H atoms and shaded spheres represent A^- ions.(K⁺,H₃O⁺,OH^-,and solvent H₂O molecules have been omitted for clarity. ) -Which of the solutions are buffer solutions?

What is the Henderson-Hasselbalch equation for the acidic buffer HA/A^-?

What is the pH of the solution formed when 50 mL of 0.250 M NaOH is added to 50 mL of 0.120 M HCl?

TRIS {(HOCH₂) ₃CNH₂} is one of the most common buffers used in biochemistry.A solution is prepared by adding enough TRIS and 12 M HCl(aq) to give 1.00 L of solution with [TRIS] = 0.30 M and [TRISH⁺] = 0.60 M.What is the pH of this buffered system if the pK_b is 5.92?

What is the K_a of the amino acid glycine if it is 75.0% dissociated at pH = 10.08?

What is the [CH₃CO₂^-]/[CH₃CO₂H] ratio necessary to make a buffer solution with a pH of 4.44? K_a = 1.8 × 10^-5 for CH₃CO₂H.

When 50 mL of 0.10 M NaF is added to 50 mL of 0.10 M HF,relative to the pH of the 0.10 M HF solution the pH of the resulting solution will

Calculate the K_sp for silver sulfite if the solubility of Ag₂SO₃ in pure water is 4.6 × 10^-3g/L.

Calculate the molar solubility of thallium(I) chloride in 0.40 M NaCl at 25°C.K_sp for TlCl is 1) 7 × 10^-4.

Which is a net ionic equation for the neutralization reaction of a weak acid with a weak base?

Which of these neutralization reactions has a pH < 7 when equal molar amounts of acid and base are mixed?

What is the pH at the equivalence point of a weak base-strong acid titration if 20.00 mL of NaOCl requires 28.30 mL of 0.50 M HCl? K_a = 3.0 × 10^-8 for HOCl.

What is the pH of a buffer solution made by mixing 50.0 mL of 0.100 M potassium hydrogen phthalate with 13.6 mL of 0.100 M NaOH and diluting the mixture to 100.0 mL with water? The K_a2 for hydrogen phthalate is 3.1 × 10^-6.

What is the pH of a solution made by mixing 10.00 mL of 0.10 M acetic acid with 10.00 mL of 0.10 M KOH? Assume that the volumes of the solutions are additive.K_a =1.8 × 10^-5 for CH₃CO₂H.

The following pictures represent solutions that contain a weak acid HA and/or its potassium salt KA.Unshaded spheres represent H atoms and shaded spheres represent A^- ions.(K⁺,H₃O⁺,OH^-,and solvent H₂O molecules have been omitted for clarity. ) -Which solution has the highest pH?

The following plot shows two titration curves,each representing the titration of 50.00 mL of 0.100 M acid with 0.100 M NaOH. -Which points a-d represent the half-equivalence point and the equivalence point,respectively,for the titration of a weak acid?

Exam 15: Applications of Aqueous Equilibria

The following pictures represent solutions that contain a weak acid HA and/or its potassium salt KA.Unshaded spheres represent H atoms and shaded spheres represent A- ions.(K+,H3O+,OH-,and solvent H2O molecules have been omitted for clarity. ) -Which of the solutions are buffer solutions?

What is the Henderson-Hasselbalch equation for the acidic buffer HA/A-?

What is the pH of the solution formed when 50 mL of 0.250 M NaOH is added to 50 mL of 0.120 M HCl?

TRIS {(HOCH2) 3CNH2} is one of the most common buffers used in biochemistry.A solution is prepared by adding enough TRIS and 12 M HCl(aq) to give 1.00 L of solution with [TRIS] = 0.30 M and [TRISH+] = 0.60 M.What is the pH of this buffered system if the pKb is 5.92?

What is the Ka of the amino acid glycine if it is 75.0% dissociated at pH = 10.08?

What is the [CH3CO2-]/[CH3CO2H] ratio necessary to make a buffer solution with a pH of 4.44? Ka = 1.8 × 10-5 for CH3CO2H.

When 50 mL of 0.10 M NaF is added to 50 mL of 0.10 M HF,relative to the pH of the 0.10 M HF solution the pH of the resulting solution will

Calculate the Ksp for silver sulfite if the solubility of Ag2SO3 in pure water is 4.6 × 10-3 g/L.

Calculate the molar solubility of thallium(I) chloride in 0.40 M NaCl at 25°C.Ksp for TlCl is 1) 7 × 10-4.

Which is a net ionic equation for the neutralization reaction of a weak acid with a weak base?

Which of these neutralization reactions has a pH < 7 when equal molar amounts of acid and base are mixed?

What is the pH at the equivalence point of a weak base-strong acid titration if 20.00 mL of NaOCl requires 28.30 mL of 0.50 M HCl? Ka = 3.0 × 10-8 for HOCl.

What is the pH of a buffer solution made by mixing 50.0 mL of 0.100 M potassium hydrogen phthalate with 13.6 mL of 0.100 M NaOH and diluting the mixture to 100.0 mL with water? The Ka2 for hydrogen phthalate is 3.1 × 10-6.

What is the pH of a solution made by mixing 10.00 mL of 0.10 M acetic acid with 10.00 mL of 0.10 M KOH? Assume that the volumes of the solutions are additive.Ka =1.8 × 10-5 for CH3CO2H.

The following pictures represent solutions that contain a weak acid HA and/or its potassium salt KA.Unshaded spheres represent H atoms and shaded spheres represent A- ions.(K+,H3O+,OH-,and solvent H2O molecules have been omitted for clarity. ) -Which solution has the highest pH?

The following plot shows two titration curves,each representing the titration of 50.00 mL of 0.100 M acid with 0.100 M NaOH. -Which points a-d represent the half-equivalence point and the equivalence point,respectively,for the titration of a weak acid?

The following pictures represent solutions that contain a weak acid HA and/or its potassium salt KA.Unshaded spheres represent H atoms and shaded spheres represent A^- ions.(K⁺,H₃O⁺,OH^-,and solvent H₂O molecules have been omitted for clarity. ) -Which of the solutions are buffer solutions?

What is the Henderson-Hasselbalch equation for the acidic buffer HA/A^-?

TRIS {(HOCH₂) ₃CNH₂} is one of the most common buffers used in biochemistry.A solution is prepared by adding enough TRIS and 12 M HCl(aq) to give 1.00 L of solution with [TRIS] = 0.30 M and [TRISH⁺] = 0.60 M.What is the pH of this buffered system if the pK_b is 5.92?

What is the K_a of the amino acid glycine if it is 75.0% dissociated at pH = 10.08?

What is the [CH₃CO₂^-]/[CH₃CO₂H] ratio necessary to make a buffer solution with a pH of 4.44? K_a = 1.8 × 10^-5 for CH₃CO₂H.

Calculate the K_sp for silver sulfite if the solubility of Ag₂SO₃ in pure water is 4.6 × 10^-3g/L.

Calculate the molar solubility of thallium(I) chloride in 0.40 M NaCl at 25°C.K_sp for TlCl is 1) 7 × 10^-4.

What is the pH at the equivalence point of a weak base-strong acid titration if 20.00 mL of NaOCl requires 28.30 mL of 0.50 M HCl? K_a = 3.0 × 10^-8 for HOCl.

What is the pH of a buffer solution made by mixing 50.0 mL of 0.100 M potassium hydrogen phthalate with 13.6 mL of 0.100 M NaOH and diluting the mixture to 100.0 mL with water? The K_a2 for hydrogen phthalate is 3.1 × 10^-6.

What is the pH of a solution made by mixing 10.00 mL of 0.10 M acetic acid with 10.00 mL of 0.10 M KOH? Assume that the volumes of the solutions are additive.K_a =1.8 × 10^-5 for CH₃CO₂H.

The following pictures represent solutions that contain a weak acid HA and/or its potassium salt KA.Unshaded spheres represent H atoms and shaded spheres represent A^- ions.(K⁺,H₃O⁺,OH^-,and solvent H₂O molecules have been omitted for clarity. ) -Which solution has the highest pH?