Question 1

Calculate the pH of a buffer that is 0.105 mol L-1 CH3COOH and 0.146 mol L-1 CH3COOK. The Ka for CH3COOH is 1.8 × 10-5.

Accepted Answer

A) 4.89 
B) 9.11 
C) 4.74 
D) 9.26 
E) 4.60 
A) 4.89 
B) 9.11 
C) 4.74 
D) 9.26 
E) 4.60

Question 2

What is the approximate pH at the equivalence point of a weak acid-strong base titration if 25 mL of aqueous hydrofluoric acid requires 30.00 mL of 0.400 mol L-1 NaOH? Ka = 6.76 × 10-4 for HF.

Accepted Answer

A) 1.74 
B) 5.75 
C) 8.25 
D) 12.26 
A) 1.74 
B) 5.75 
C) 8.25 
D) 12.26

Question 3

Which of the following is the correct equation relating Q to Ksp for a supersaturated 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

When titrating a monoprotic strong acid with a weak base at 25 °C, the

Accepted Answer

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

Question 5

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 6

Sketch the titration curve for a strong acid titrated with a strong base. Make sure to indicate the equivalence point (and whether the equivalence point is acidic, basic, or neutral)and the buffer region.

Accepted Answer

See the fi

Question 7

What is the pH of a solution prepared by mixing 50.00 mL of 0.10 mol L-1 methylamine, CH3NH2, with 20.00 mL of 0.10 mol L-1 methylammonium chloride, CH3NH3Cl? Assume that the volume of the solutions are additive and that Kb = 3.70 × 10-4 for methylamine.

Accepted Answer

A) 10.17 
B) 10.57 
C) 10.97 
D) 11.78 
A) 10.17 
B) 10.57 
C) 10.97 
D) 11.78

Question 8

Identify the pH of normal blood.

Accepted Answer

A) 7.0 
B) 7.2 
C) 7.4 
D) 7.6 
E) 7.8 
A) 7.0 
B) 7.2 
C) 7.4 
D) 7.6 
E) 7.8

Question 9

Sodium hypochlorite, NaOCl, is the active ingredient in household bleach. What is the concentration of hypochlorite ion if 20.00 mL of bleach requires 32.00 mL of 0.500 mol L-1 HCl to reach the equivalence point?

Accepted Answer

A) 0.300 mol L-1 
B) 0.312 mol L-1 
C) 0.800 mol L-1 
D) 1.30 mol L-1 
A) 0.300 mol L-1 
B) 0.312 mol L-1 
C) 0.800 mol L-1 
D) 1.30 mol L-1

Question 10

What is the hydronium ion concentration in a solution prepared by mixing 50.00 mL of 0.10 mol L-1 HCN with 50.00 mL of 0.030 mol L-1 NaCN? Assume that the volumes of the solutions are additive and that Ka = 4.9 × 10-10 for HCN.

Accepted Answer

A) 1.5 × 10-10 mol L-1 
B) 4.9 × 10-10 mol L-1 
C) 1.6 × 10-9 mol L-1 
D) 7.0 × 10-6 mol L-1 
A) 1.5 × 10-10 mol L-1 
B) 4.9 × 10-10 mol L-1 
C) 1.6 × 10-9 mol L-1 
D) 7.0 × 10-6 mol L-1

Question 11

What is the pH of the resulting solution if 25.00 mL of 0.10 mol L-1 acetic acid is added to 10.00 mL of 0.10 mol L-1 NaOH? Assume that the volumes of the solutions are additive. Ka = 1.8 × 10-5 for CH3COOH.

Accepted Answer

A) 9.43 
B) 9.08 
C) 4.92 
D) 4.57 
A) 9.43 
B) 9.08 
C) 4.92 
D) 4.57

Question 12

Identify the expression for the solubility product constant for Ca3(PO4)2.

Accepted Answer

A)    
B)    
C)    
D) [Ca2+]2[PO43-]3 
E) [Ca2+]3[PO43-]2 
A)    
B)    
C)    
D) [Ca2+]2[PO43-]3 
E) [Ca2+]3[PO43-]2

Question 13

Determine the molar solubility of AgBr in a solution containing 0.150 mol L-1 NaBr. Ksp (AgBr)= 7.7 × 10-13.

Accepted Answer

A) 8.8 × 10-7 mol L-1 
B) 3.9 × 10-13 mol L-1 
C) 5.8 × 10-5 mol L-1 
D) 5.1 × 10-12 mol L-1 
E) 0.150 mol L-1 
A) 8.8 × 10-7 mol L-1 
B) 3.9 × 10-13 mol L-1 
C) 5.8 × 10-5 mol L-1 
D) 5.1 × 10-12 mol L-1 
E) 0.150 mol L-1

Question 14

What is the molar solubility of AgCl in 0.40 mol L-1 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 mol L-1 
B) 2.0 × 10-5 mol L-1 
C) 2.2 × 10-2 mol L-1 
D) 5.5 × 10-2 mol L-1 
A) 1.3 × 10-5 mol L-1 
B) 2.0 × 10-5 mol L-1 
C) 2.2 × 10-2 mol L-1 
D) 5.5 × 10-2 mol L-1

Question 15

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 mol L-1 HCl for complete neutralization? Ka = 3.0 × 10-8 for HOCl.

Accepted Answer

A) 0.30 
B) 3.18 
C) 3.76 
D) 4.03 
A) 0.30 
B) 3.18 
C) 3.76 
D) 4.03

Question 16

How many millilitres of 0.0850 mol L-1 NaOH are required to titrate 25.0 mL of 0.0720 mol L-1 HBr to the equivalence point?

Accepted Answer

A) 21.2 
B) 0.245 
C) 3.92 
D) 0.153 
E) 29.5 
A) 21.2 
B) 0.245 
C) 3.92 
D) 0.153 
E) 29.5

Question 17

Calculate the pH of a solution formed by mixing 250.0 mL of 0.15 mol L-1 NH4Cl with 200.0 mL of 0.12 mol L-1 NH3. The Kb for NH3 is 1.8 × 10-5.

Accepted Answer

A) 9.06 
B) 9.45 
C) 4.55 
D) 4.74 
E) 9.26 
A) 9.06 
B) 9.45 
C) 4.55 
D) 4.74 
E) 9.26

Question 18

Match the following.

-pH = 7

Accepted Answer

A) equivalence point of a weak base-strong acid titration 
B) equivalence point of a weak acid-strong base titration 
C) three-quarters of the way to second equivalence point of a diprotic acid-strong base titration 
D) halfway to equivalence point of a weak acid-strong base titration 
E) equivalence point of a strong acid-strong base titration 
A) equivalence point of a weak base-strong acid titration 
B) equivalence point of a weak acid-strong base titration 
C) three-quarters of the way to second equivalence point of a diprotic acid-strong base titration 
D) halfway to equivalence point of a weak acid-strong base titration 
E) equivalence point of a strong acid-strong base titration

Question 19

A 1.50 L buffer solution is 0.250 mol L-1 in HF and 0.250 mol L-1 in NaF. Calculate the pH of the solution after the addition of 0.0500 moles of solid NaOH. Assume no volume change upon the addition of the base. The Ka for HF is 3.5 × 10-4.

Accepted Answer

A) 3.34 
B) 3.46 
C) 3.57 
D) 3.63 
E) 2.89 
A) 3.34 
B) 3.46 
C) 3.57 
D) 3.63 
E) 2.89

Question 20

What is the maximum ratio of conjugate base to acid in an effective buffer?

Accepted Answer

A) 2 
B) 5 
C) 10 
D) 20 
E) 15 
A) 2 
B) 5 
C) 10 
D) 20 
E) 15

Exam 16: Aqueous Ionic Equilibrium

Calculate the pH of a buffer that is 0.105 mol L-1 CH3COOH and 0.146 mol L-1 CH3COOK. The Ka for CH3COOH is 1.8 × 10-5.

What is the approximate pH at the equivalence point of a weak acid-strong base titration if 25 mL of aqueous hydrofluoric acid requires 30.00 mL of 0.400 mol L-1 NaOH? Ka = 6.76 × 10-4 for HF.

Which of the following is the correct equation relating Q to Ksp for a supersaturated solution?

When titrating a monoprotic strong acid with a weak base at 25 °C, the

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?

Sketch the titration curve for a strong acid titrated with a strong base. Make sure to indicate the equivalence point (and whether the equivalence point is acidic, basic, or neutral)and the buffer region.

What is the pH of a solution prepared by mixing 50.00 mL of 0.10 mol L-1 methylamine, CH3NH2, with 20.00 mL of 0.10 mol L-1 methylammonium chloride, CH3NH3Cl? Assume that the volume of the solutions are additive and that Kb = 3.70 × 10-4 for methylamine.

Identify the pH of normal blood.

Sodium hypochlorite, NaOCl, is the active ingredient in household bleach. What is the concentration of hypochlorite ion if 20.00 mL of bleach requires 32.00 mL of 0.500 mol L-1 HCl to reach the equivalence point?

What is the hydronium ion concentration in a solution prepared by mixing 50.00 mL of 0.10 mol L-1 HCN with 50.00 mL of 0.030 mol L-1 NaCN? Assume that the volumes of the solutions are additive and that Ka = 4.9 × 10-10 for HCN.

What is the pH of the resulting solution if 25.00 mL of 0.10 mol L-1 acetic acid is added to 10.00 mL of 0.10 mol L-1 NaOH? Assume that the volumes of the solutions are additive. Ka = 1.8 × 10-5 for CH3COOH.

Identify the expression for the solubility product constant for Ca3(PO4)2.

Determine the molar solubility of AgBr in a solution containing 0.150 mol L-1 NaBr. Ksp (AgBr)= 7.7 × 10-13.

What is the molar solubility of AgCl in 0.40 mol L-1 NH3? Ksp for AgCl is 1.8 × 10-10 and Kf for Ag(NH3)2+ is 1.7 × 107.

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 mol L-1 HCl for complete neutralization? Ka = 3.0 × 10-8 for HOCl.

How many millilitres of 0.0850 mol L-1 NaOH are required to titrate 25.0 mL of 0.0720 mol L-1 HBr to the equivalence point?

Calculate the pH of a solution formed by mixing 250.0 mL of 0.15 mol L-1 NH4Cl with 200.0 mL of 0.12 mol L-1 NH3. The Kb for NH3 is 1.8 × 10-5.

Match the following. -pH = 7

A 1.50 L buffer solution is 0.250 mol L-1 in HF and 0.250 mol L-1 in NaF. Calculate the pH of the solution after the addition of 0.0500 moles of solid NaOH. Assume no volume change upon the addition of the base. The Ka for HF is 3.5 × 10-4.

What is the maximum ratio of conjugate base to acid in an effective buffer?

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Calculate the pH of a buffer that is 0.105 mol L^-1 CH₃COOH and 0.146 mol L^-1 CH₃COOK. The K_a for CH₃COOH is 1.8 × 10^-5.

What is the approximate pH at the equivalence point of a weak acid-strong base titration if 25 mL of aqueous hydrofluoric acid requires 30.00 mL of 0.400 mol L^-1 NaOH? K_a = 6.76 × 10^-4 for HF.

Which of the following is the correct equation relating Q to K_sp for a supersaturated solution?

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

What is the pH of a solution prepared by mixing 50.00 mL of 0.10 mol L^-1 methylamine, CH₃NH₂, with 20.00 mL of 0.10 mol L^-1 methylammonium chloride, CH₃NH₃Cl? Assume that the volume of the solutions are additive and that K_b = 3.70 × 10^-4 for methylamine.

Sodium hypochlorite, NaOCl, is the active ingredient in household bleach. What is the concentration of hypochlorite ion if 20.00 mL of bleach requires 32.00 mL of 0.500 mol L^-1 HCl to reach the equivalence point?

What is the hydronium ion concentration in a solution prepared by mixing 50.00 mL of 0.10 mol L^-1 HCN with 50.00 mL of 0.030 mol L^-1 NaCN? Assume that the volumes of the solutions are additive and that K_a = 4.9 × 10^-10for HCN.

What is the pH of the resulting solution if 25.00 mL of 0.10 mol L^-1 acetic acid is added to 10.00 mL of 0.10 mol L^-1 NaOH? Assume that the volumes of the solutions are additive. K_a = 1.8 × 10^-5for CH₃COOH.

Identify the expression for the solubility product constant for Ca₃(PO₄)₂.

Determine the molar solubility of AgBr in a solution containing 0.150 mol L^-1 NaBr. K_sp (AgBr)= 7.7 × 10^-13.

What is the molar solubility of AgCl in 0.40 mol L^-1 NH₃? K_sp for AgCl is 1.8 × 10^-10 and K_f for Ag(NH₃)₂⁺ is 1.7 × 10⁷.

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 mol L^-1 HCl for complete neutralization? K_a = 3.0 × 10^-8 for HOCl.

How many millilitres of 0.0850 mol L^-1 NaOH are required to titrate 25.0 mL of 0.0720 mol L^-1 HBr to the equivalence point?

Calculate the pH of a solution formed by mixing 250.0 mL of 0.15 mol L^-1 NH₄Cl with 200.0 mL of 0.12 mol L^-1 NH₃. The K_b for NH₃ is 1.8 × 10^-5.

A 1.50 L buffer solution is 0.250 mol L^-1 in HF and 0.250 mol L^-1 in NaF. Calculate the pH of the solution after the addition of 0.0500 moles of solid NaOH. Assume no volume change upon the addition of the base. The K_a for HF is 3.5 × 10^-4.