Question 1

If the pKa of HCOOH is 3.74 and the pH of an HCOOH/HCOONa solution is 3.11, which of the following is TRUE?

Accepted Answer

A)  [HCOOH]  [HCOONa] 
E)  [HCOOH] >> [HCOONa] 
A)  [HCOOH]  [HCOONa] 
E)  [HCOOH] >> [HCOONa]

Question 2

Determine the molar solubility of BaF2 in a solution containing 0.0750 mol L-1 LiF. Ksp (BaF2) = 1.7 × 10-6.

Accepted Answer

A)  2.3 × 10-5 mol L-1 
B)  8.5 × 10-7 mol L-1 
C)  1.2 × 10-2 mol L-1 
D)  0.075 mol L-1 
E)  3.0 × 10-4 mol L-1 
A)  2.3 × 10-5 mol L-1 
B)  8.5 × 10-7 mol L-1 
C)  1.2 × 10-2 mol L-1 
D)  0.075 mol L-1 
E)  3.0 × 10-4 mol L-1

Question 3

Which of the following is the correct equation relating Q to Ksp for an unsaturated solution?

Accepted Answer

A)  Q > Ksp 
B)  Q sp 
C)  Q = Ksp 
D)  Q ≠ Ksp 
E)  Q ≥ Ksp 
A)  Q > Ksp 
B)  Q sp 
C)  Q = Ksp 
D)  Q ≠ Ksp 
E)  Q ≥ Ksp

Question 4

Which of the following acids (listed with pKa values) and its conjugate would be the best choice to make a buffer with a pH of 2.12?

Accepted Answer

A)  HC7H5O2, pKa = 4.19 
B)  CH3COOH, pKa = 4.74 
C)  HClO, pKa = 7.54 
D)  HCN, pKa = 9.31 
E)  HClO2, pKa = 1.96 
A)  HC7H5O2, pKa = 4.19 
B)  CH3COOH, pKa = 4.74 
C)  HClO, pKa = 7.54 
D)  HCN, pKa = 9.31 
E)  HClO2, pKa = 1.96

Question 5

A 25.0 mL sample of 0.150 mol L-1 formic acid is titrated with a 0.150 mol L-1 NaOH solution. What is the pH at the equivalence point? The   of formic acid is 1.8 × 10-4.

Accepted Answer

A)  11.38 
B)  10.26 
C)  5.69 
D)  8.31 
E)  7.00 
A)  11.38 
B)  10.26 
C)  5.69 
D)  8.31 
E)  7.00

Question 6

A 100.0 mL sample of 0.20 mol L-1 HF is titrated with 0.10 mol L-1 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 
A)  4.15 
B)  0.70 
C)  2.08 
D)  3.46 
E)  1.00

Question 7

If the pKa of HCOOH is 3.74 and the pH of an HCOOH/HCOONa buffer solution is 3.74, which of the following is TRUE?

Accepted Answer

A)  [HCOOH] > [HCOONa] 
B)  [HCOOH] = [HCOONa] 
C)  [HCOOH] > [HCOONa] 
A)  [HCOOH] > [HCOONa] 
B)  [HCOOH] = [HCOONa] 
C)  [HCOOH] > [HCOONa]

Question 8

What is the pH of a solution prepared by mixing 25.00 mL of 0.10 mol L-1 CH3COOH with 25.00 mL of 0.0 10 mol L-1 CH3COONa? Assume that the volume of the solutions are additive and that Ka = 1.8 × 10-5 for CH3COOH.

Accepted Answer

A)  2.87 
B)  3.74 
C)  4.7 5 
D)  5. 74 
A)  2.87 
B)  3.74 
C)  4.7 5 
D)  5. 74

Question 9

When titrating a weak monoprotic acid with NaOH at 25 °C, the ________.

Accepted Answer

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

Question 10

A sample contains Ba3(PO4)2, CdS, AgCl, NH4Cl, and ZnS. Identify the precipitate formed upon the addition of 6 mol L-1 HCl.

Accepted Answer

A)  Ba3(PO4)2 
B)  CdS 
C)  AgCl 
D)  NH4Cl 
E)  ZnS 
A)  Ba3(PO4)2 
B)  CdS 
C)  AgCl 
D)  NH4Cl 
E)  ZnS

Question 11

Which of the following compounds' solubility will not be affected by a low pH in solution?

Accepted Answer

A)  AgCl 
B)  Mg(OH)2 
C)  CaF2 
D)  CuS 
E)  BaCO3 
A)  AgCl 
B)  Mg(OH)2 
C)  CaF2 
D)  CuS 
E)  BaCO3

Question 12

What is the [CH3COO-]/[CH3COOH] ratio necessary to make a buffer solution with a pH of 4. 34? Ka = 1.8 × 10-5 for CH3COOH.

Accepted Answer

A)  0. 39:1 
B)  0. 91:1 
C)  1. 09:1 
D)  2.5:1 
A)  0. 39:1 
B)  0. 91:1 
C)  1. 09:1 
D)  2.5:1

Question 13

Determine the molar solubility of BaF2 in pure water. Ksp for BaF2 = 2.45 × 10-5.

Accepted Answer

A)  1.83 × 10-2 mol L-1 
B)  1.23 × 10-5 mol L-1 
C)  2.90 × 10-2 mol L-1 
D)  4.95 × 10-3 mol L-1 
E)  6.13 × 10-6 mol L-1 
A)  1.83 × 10-2 mol L-1 
B)  1.23 × 10-5 mol L-1 
C)  2.90 × 10-2 mol L-1 
D)  4.95 × 10-3 mol L-1 
E)  6.13 × 10-6 mol L-1

Question 14

A 100.0 mL sample of 0.10 mol L-1 NH3 is titrated with 0.10 mol L-1 HNO3. Determine the pH of the solution after the addition of 100.0 mL of HNO3. The Kb of NH3 is 1.8 × 10-5.

Accepted Answer

A)  6.58 
B)  10.56 
C)  8.72 
D)  3.44 
E)  5.28 
A)  6.58 
B)  10.56 
C)  8.72 
D)  3.44 
E)  5.28

Question 15

A 1.00 L buffer solution is 0.150 mol L-1 in C6H5COOH and 0.250 mol L-1 in C6H5COOLi. Calculate the pH of the solution after the addition of 100.0 mL of 1.00 mol L-1 HCl. The Ka for HC7H5O2 is 6.5 × 10-5.

Accepted Answer

A)  4.19 
B)  5.03 
C)  4.41 
D)  3.34 
E)  3.97 
A)  4.19 
B)  5.03 
C)  4.41 
D)  3.34 
E)  3.97

Question 16

What is the pH of the resulting solution if 45 mL of 0.432 mol L-1 methylamine, CH3NH2, is added to 15 mL of 0.234 mol L-1 HCl? Assume that the volumes of the solutions are additive. Ka = 2.70 × 10-11 for CH3NH3+.

Accepted Answer

A)  2.77 
B)  4.09 
C)  9.91 
D)  11.23 
A)  2.77 
B)  4.09 
C)  9.91 
D)  11.23

Question 17

A solution containing AgNO3 is mixed with a solution of NaCl to form a solution that is 0.10 mol L-1 in AgNO3 and 0.075 mol L-1 in NaCl. What will happen once these solutions are mixed? Ksp (AgCl) = 1.77 × 10-10.

Accepted Answer

A)  Nothing will happen since the molar solubility of AgCl is higher than the solution concentrations. 
B)  Silver chloride will precipitate out of the solution, leaving an unsaturated solution of AgCl. 
C)  Silver chloride will precipitate out of the solution, leaving a saturated AgCl solution. 
D)  Nothing will happen since NaCl and AgNO3 are both soluble compounds. 
E)  Silver chloride will precipitate, leaving a pure solution of NaNO3. 
A)  Nothing will happen since the molar solubility of AgCl is higher than the solution concentrations. 
B)  Silver chloride will precipitate out of the solution, leaving an unsaturated solution of AgCl. 
C)  Silver chloride will precipitate out of the solution, leaving a saturated AgCl solution. 
D)  Nothing will happen since NaCl and AgNO3 are both soluble compounds. 
E)  Silver chloride will precipitate, leaving a pure solution of NaNO3.

Question 18

Calculate the mole ratio of C6H5COONa to C6H5COOH required to make a buffer with pH of 4.68. Ka of C6H5COOH is 6.3 × 10-5.

Accepted Answer

A)  0.122 
B)  3.02 
C)  0.75 
D)  1.22 
E)  10.0 
A)  0.122 
B)  3.02 
C)  0.75 
D)  1.22 
E)  10.0

Question 19

What is the approximate pH at the equivalence point of a weak acid-strong base titration if 25 mL of aqueous formic acid (HCOOH) requires 29.80 mL of 0. 3567 mol L-1 NaOH? Ka =1.8 × 10-4   for formic acid.

Accepted Answer

A)  2. 06 
B)  5. 48 
C)  8. 52 
D)  11.94 
A)  2. 06 
B)  5. 48 
C)  8. 52 
D)  11.94

Question 20

What volume of 5.00 × 10-3 mol L-1 HNO3 is needed to titrate 80.00 mL of 5.00 × 10-3 mol L-1 Ca(OH)2 to the equivalence point?

Accepted Answer

A)  10.0 mL 
B)  40.0 mL 
C)  80.0 mL 
D)  160. mL 
A)  10.0 mL 
B)  40.0 mL 
C)  80.0 mL 
D)  160. mL

Exam 16: Aqueous Ionic Equilibrium

If the pKa of HCOOH is 3.74 and the pH of an HCOOH/HCOONa solution is 3.11, which of the following is TRUE?

Determine the molar solubility of BaF2 in a solution containing 0.0750 mol L-1 LiF. Ksp (BaF2) = 1.7 × 10-6.

Which of the following is the correct equation relating Q to Ksp for an unsaturated solution?

Which of the following acids (listed with pKa values) and its conjugate would be the best choice to make a buffer with a pH of 2.12?

A 25.0 mL sample of 0.150 mol L-1 formic acid is titrated with a 0.150 mol L-1 NaOH solution. What is the pH at the equivalence point? The of formic acid is 1.8 × 10-4.

A 100.0 mL sample of 0.20 mol L-1 HF is titrated with 0.10 mol L-1 KOH. Determine the pH of the solution before the addition of any KOH. The Ka of HF is 3.5 × 10-4.

If the pKa of HCOOH is 3.74 and the pH of an HCOOH/HCOONa buffer solution is 3.74, which of the following is TRUE?

What is the pH of a solution prepared by mixing 25.00 mL of 0.10 mol L-1 CH3COOH with 25.00 mL of 0.0 10 mol L-1 CH3COONa? Assume that the volume of the solutions are additive and that Ka = 1.8 × 10-5 for CH3COOH.

When titrating a weak monoprotic acid with NaOH at 25 °C, the ________.

A sample contains Ba3(PO4)2, CdS, AgCl, NH4Cl, and ZnS. Identify the precipitate formed upon the addition of 6 mol L-1 HCl.

Which of the following compounds' solubility will not be affected by a low pH in solution?

What is the [CH3COO-]/[CH3COOH] ratio necessary to make a buffer solution with a pH of 4. 34? Ka = 1.8 × 10-5 for CH3COOH.

Determine the molar solubility of BaF2 in pure water. Ksp for BaF2 = 2.45 × 10-5.

A 100.0 mL sample of 0.10 mol L-1 NH3 is titrated with 0.10 mol L-1 HNO3. Determine the pH of the solution after the addition of 100.0 mL of HNO3. The Kb of NH3 is 1.8 × 10-5.

A 1.00 L buffer solution is 0.150 mol L-1 in C6H5COOH and 0.250 mol L-1 in C6H5COOLi. Calculate the pH of the solution after the addition of 100.0 mL of 1.00 mol L-1 HCl. The Ka for HC7H5O2 is 6.5 × 10-5.

What is the pH of the resulting solution if 45 mL of 0.432 mol L-1 methylamine, CH3NH2, is added to 15 mL of 0.234 mol L-1 HCl? Assume that the volumes of the solutions are additive. Ka = 2.70 × 10-11 for CH3NH3+.

A solution containing AgNO3 is mixed with a solution of NaCl to form a solution that is 0.10 mol L-1 in AgNO3 and 0.075 mol L-1 in NaCl. What will happen once these solutions are mixed? Ksp (AgCl) = 1.77 × 10-10.

Calculate the mole ratio of C6H5COONa to C6H5COOH required to make a buffer with pH of 4.68. Ka of C6H5COOH is 6.3 × 10-5.

What is the approximate pH at the equivalence point of a weak acid-strong base titration if 25 mL of aqueous formic acid (HCOOH) requires 29.80 mL of 0. 3567 mol L-1 NaOH? Ka =1.8 × 10-4 for formic acid.

What volume of 5.00 × 10-3 mol L-1 HNO3 is needed to titrate 80.00 mL of 5.00 × 10-3 mol L-1 Ca(OH)2 to the equivalence point?

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Filters

If the pKa of HCOOH is 3.74 and the pH of an HCOOH/HCOONasolution is 3.11, which of the following is TRUE?

Determine the molar solubility of BaF₂ in a solution containing 0.0750 mol L^-1 LiF. K_sp (BaF₂) = 1.7 × 10^-6.

Which of the following is the correct equation relating Q to K_sp for an unsaturated solution?

Which of the following acids (listed with pK_a values) and its conjugate would be the best choice to make a buffer with a pH of 2.12?

A 25.0 mL sample of 0.150 mol L^-1 formic acid is titrated with a 0.150 mol L^-1 NaOH solution. What is the pH at the equivalence point? The of formic acid is 1.8 × 10^-4.

A 100.0 mL sample of 0.20 mol L^-1 HF is titrated with 0.10 mol L^-1 KOH. Determine the pH of the solution before the addition of any KOH. The K_a of HF is 3.5 × 10^-4.

If the pK_a of HCOOH is 3.74 and the pH of an HCOOH/HCOONabuffer solution is 3.74, which of the following is TRUE?

What is the pH of a solution prepared by mixing 25.00 mL of 0.10 mol L^-1 CH₃COOH with 25.00 mL of 0.0 10 mol L^-1 CH₃COONa? Assume that the volume of the solutions are additive and that K_a = 1.8 × 10^-5 for CH₃COOH.

A sample contains Ba₃(PO₄)₂,CdS, AgCl, NH₄Cl, and ZnS. Identify the precipitate formed upon the addition of 6 mol L^-1 HCl.

What is the [CH₃COO^-]/[CH₃COOH] ratio necessary to make a buffer solution with a pH of 4. 34? K_a = 1.8 × 10^-5for CH3COOH.

Determine the molar solubility of BaF₂in pure water. K_sp for BaF₂ = 2.45 × 10^-5.

A 100.0 mL sample of 0.10 mol L^-1 NH₃ is titrated with 0.10 mol L^-1 HNO₃. Determine the pH of the solution after the addition of 100.0 mL of HNO₃. The K_b of NH₃ is 1.8 × 10^-5.

A 1.00 L buffer solution is 0.150 mol L^-1 in C₆H₅COOH and 0.250 mol L^-1 in C₆H₅COOLi. Calculate the pH of the solution after the addition of 100.0 mL of 1.00 mol L^-1 HCl. The K_a for HC₇H₅O₂ is 6.5 × 10^-5.

What is the pH of the resulting solution if 45 mL of 0.432 mol L^-1 methylamine, CH₃NH₂, is added to 15 mL of 0.234 mol L^-1 HCl? Assume that the volumes of the solutions are additive. K_a = 2.70 × 10^-11for CH₃NH₃⁺.

A solution containing AgNO₃ is mixed with a solution of NaCl to form a solution that is 0.10 mol L^-1 in AgNO₃ and 0.075 mol L^-1 in NaCl. What will happen once these solutions are mixed? K_sp (AgCl) = 1.77 × 10^-10.

Calculate the mole ratio of C₆H₅COONa to C₆H₅COOH required to make a buffer with pH of 4.68. K_a of C₆H₅COOH is 6.3 × 10^-5.

What is the approximate pH at the equivalence point of a weak acid-strong base titration if 25 mL of aqueous formic acid (HCOOH) requires 29.80 mL of 0. 3567 mol L^-1 NaOH? K_a =1.8 × 10^-4 for formic acid.

What volume of 5.00 × 10^-3 mol L^-1 HNO₃ is needed to titrate 80.00 mL of 5.00 × 10^-3 mol L^-1 Ca(OH)₂ to the equivalence point?