Deck 16: Aqueous Ionic Equilibrium

Question 1

Fluffy,your prized Himalayan cat,was outside when your dad was changing the antifreeze in the car.Fluffy licked up a large amount of the antifreeze off the driveway.You live many miles from the veterinarian.What could you give Fluffy to drink to counteract the effects of antifreeze?

A)mineral oil
B)rubbing alcohol
C)a strong alcoholic drink
D)gasoline
E)vegetable oil

Answer 1

a strong alcoholic drink

Question 2

Which of the following solutions is a good buffer system?

A)a solution that is 0.10 M HC₂H₃O₂ and 0.10 M LiC₂H₃O₂
B)a solution that is 0.10 M HF and 0.10 M NaC₂H₃O₂
C)a solution that is 0.10 M HCl and 0.10 M NH₄⁺
D)a solution that is 0.10 M NaOH and 0.10 M KOH
E)None of the above are buffer systems.

Answer 2

a solution that is 0.10 M HC₂H₃O₂ and 0.10 M LiC₂H₃O₂

Question 3

You wish to prepare an HC₂H₃O₂ buffer with a pH of 4.24.If the pK_a of is 4.74,what ratio of
C₂H₃O₂^-/HC₂H₃O₂ must you use?

A)0.10
B)0.50
C)0.32
D)2.0
E)2.8

Answer 3

0.32

Question 4

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

A)[HCHO₂] < [NaCHO₂]
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 5

You wish to prepare an HC₂H₃O₂ buffer with a pH of 5.44.If the pK_a of is 4.74,what ratio of
C₂H₃O₂^-/HC₂H₃O₂ must you use?

A)0.70
B)0.20
C)1.4
D)5.0
E)1.1

Question 6

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

A)[HCHO₂] > [NaCHO₂]
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 7

Calculate the pH of a solution formed by mixing 100.0 mL of 0.20 M HClO with 200.0 mL of
0.30 M KClO.The K_a for HClO is 2.9 × 10^-8.

A)5.99
B)8.01
C)7.54
D)7.71
E)6.46

Question 8

Calculate the pH of a solution formed by mixing 150.0 mL of 0.10 M HC₇H₅O₂ with 100.0 mL of
0.30 M NaC₇H₅O₂.The K_a for HC₇H₅O₂ is 6.5 × 10^-5.

A)4.19
B)9.69
C)4.49
D)4.31
E)10.51

Question 9

Which one of the following statements is true?

A)A buffer is an aqueous solution composed of two weak acids.
B)A buffer can absorb an unlimited amount of acid or base.
C)A buffer resists pH change by neutralizing added acids and bases.
D)A buffer does not change pH when strong acid or base is added.
E)None of the above are true.

Question 10

Calculate the pH of a buffer that is 0.158 M HClO and 0.099 M NaClO.The K_a for HClO is 2.9 × 10^-8.

A)7.54
B)6.67
C)3.77
D)6.46
E)7.33

Question 11

A 1.00 L buffer solution is 0.250 M in HF and 0.250 M in NaF.Calculate the pH of the solution after the addition of 100.0 mL of 1.00 M HCl.The K_a for HF is 3.5 × 10^-4.

A)3.09
B)4.11
C)3.82
D)3.46
E)2.78

Question 12

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.

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

Question 13

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

A)[HCHO₂] < [NaCHO₂]
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 14

Which of the following solutions is a good buffer system?

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 NaOH and 0.10 M HNO₃
D)a solution that is 0.10 M HNO₃ and 0.10 M KNO₃
E)a solution that is 0.10 M HCN and 0.10 M NaCl

Question 15

Calculate the pH of a buffer that is 0.105 M HC₂H₃O₂ and 0.146 M KC₂H₃O₂.The K_a for HC₂H₃O₂ is 1.8 × 10^-5.

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

Question 16

Calculate the pH of a solution formed by mixing 250.0 mL of 0.15 M HCHO₂ with 100.0 mL of
0.20 M LiCHO₂.The K_a for HCHO₂ is 1.8 × 10^-4.

A)3.87
B)3.74
C)10.53
D)3.47
E)10.13

Question 17

A buffer solution is 0.100 M in both HC₇H₅O₂ and LiC₇H₅O₂ and has a pH of 4.19.Which of the following pH values would you be most likely to see from the addition of a small amount of a dilute solution of a strong base?

A)3.89
B)3.69
C)5.69
D)4.49
E)There is not enough information to determine.

Question 18

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

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

Question 19

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.

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

Question 20

A 1.00 L buffer solution is 0.150 M in HC₇H₅O₂ and 0.250 M in LiC₇H₅O₂.Calculate the pH of the solution after the addition of 100.0 mL of 1.00 M HCl.The K_a for HC₇H₅O₂ is 6.5 × 10^-5.

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

Question 21

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

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 the 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 22

Define buffer capacity.

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 23

Which of the following acids (listed with pK_a values)and their conjugate base would form a buffer with a pH of 8.10?

A)HC₇H₅O₂,pK_a = 4.19
B)HF,pK_a = 3.46
C)HClO,pK_a = 7.54
D)HCN,pK_a = 9.31
E)HClO₂,pK_a = 1.96

Question 24

A 100.0 mL sample of 0.180 M HClO₄ is titrated with 0.270 M LiOH.Determine the pH of the solution after the addition of 75.0 mL of LiOH.

A)12.1
B)2.65
C)11.35
D)1.89
E)13.06

Question 25

Which of the following is true?

A)An effective buffer has a [base]/[acid] ratio in the range of 10 - 100.
B)A buffer is most resistant to pH change when [acid] = [conjugate base]
C)An effective buffer has very small absolute concentrations of acid and conjugate base.
D)A buffer cannot be destroyed by adding too much strong base.It can only be destroyed by adding too much strong acid.
E)None of the above are true.

Question 26

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

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 27

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.

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

Question 28

Which of the following acids (listed with K_a values)and their conjugate base would form a buffer with a pH of 2.34?

A)HC₇H₅O₂,K_a = 6.5 × 10^-5
B)HF,K_a = 3.5 × 10^-4
C)HClO,K_a = 2.9 × 10^-8
D)HCN,K_a = 4.9 × 10^-10
E)HClO₂,K_a = 1.1 × 10^-2

Question 29

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 66.67 mL of LiOH.(This is the equivalence point. )

A)0.97
B)13.03
C)2.76
D)11.24
E)7.00

Question 30

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

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 31

Which of the following is true?

A)The equivalence point is where the amount of acid equals the amount of base during any acid-base titration.
B)At the equivalence point,the pH is always 7.
C)An indicator is not pH sensitive.
D)A titration curve is a plot of pH vs.the [base]/[acid] ratio.
E)None of the above are true.

Question 32

Identify the most common indicator.

A)Alizarin
B)Thymol blue
C)Crystal violet
D)Phenolphthalein
E)Alizarin yellow R

Question 33

Identify the indicator that can be used at the lowest pH.

A)Alizarin
B)Thymol blue
C)Crystal violet
D)Phenolphthalein
E)Alizarin yellow R

Question 34

A 1.00 L buffer solution is 0.250 M in HF and 0.250 M in LiF.Calculate the pH of the solution after the addition of 0.150 moles of solid LiOH.Assume no volume change upon the addition of base.The K_a for HF is 3.5 × 10^-4.

A)3.46
B)4.06
C)2.85
D)3.63
E)4.24

Question 35

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

A)1.74
B)1.05
C)0.74
D)0.57
E)1.57

Question 36

A 1.0 L buffer solution is 0.250 M HC₂H₃O₂ and 0.050 M LiC₂H₃O₂.Which of the following actions will destroy the buffer?

A)adding 0.050 moles of LiC₂H₃O₂
B)adding 0.050 moles of HC₂H₃O₂
C)adding 0.050 moles of HCl
D)adding 0.050 moles of NaOH
E)None of the above will destroy the buffer.

Question 37

The highest pH for an effective buffer occurs when the base is how many times as concentrated as the acid?

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

Question 38

Identify the indicator that can be used at the highest pH.

A)Alizarin
B)Thymol blue
C)Crystal violet
D)Phenolphthalein
E)Alizarin yellow R

Question 39

A 1.50 L buffer solution is 0.250 M in HF and 0.250 M 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 base.The K_a for HF is 3.5 × 10^-4.

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

Question 40

A 1.0 L buffer solution is 0.050 M HC₂H₃O₂ and 0.250 M LiC₂H₃O₂.Which of the following actions will destroy the buffer?

A)adding 0.050 moles of NaOH
B)adding 0.050 moles of HCl
C)adding 0.050 moles of HC₂H₃O₂
D)adding 0.050 moles of LiC₂H₃O₂
E)None of the above will destroy the buffer.

Question 41

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 400.0 mL HBr.

A)1.00
B)1.40
C)1.22
D)1.30
E)2.11

Question 42

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

A)AgCl
B)Mg(OH)₂
C)CaF₂
D)CuS
E)BaCO₃

Question 43

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.

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

Question 44

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 100.0 mL of HNO₃.The K_b of NH₃ is 1.8 × 10^-5.

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

Question 45

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 100.0 mL of LiOH.

A)13.13
B)12.65
C)1.35
D)0.87
E)12.95

Question 46

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 before the addition of any HBr.

A)12.86
B)13.00
C)13.30
D)0.70
E)1.00

Question 47

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.

A)12.40
B)9.33
C)5.06
D)8.94
E)12.00

Question 48

Which of the following compounds will have the highest molar solubility in pure water?

A)PbSO₄, K_sp = 1.82 × 10^-8
B)MgCO₃, K_sp = 6.82 × 10^-6
C)AgI,K_sp = 8.51 × 10^-17
D)PbS,K_sp = 9.04 × 10^-29
E)FeS,K_sp = 3.72 × 10^-19

Question 49

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

A)4.74
B)9.26
C)11.13
D)13.00
E)12.55

Question 50

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 150.0 mL of HNO₃.The K_b of NH₃ is 1.8 × 10^-5.

A)1.70
B)6.44
C)7.56
D)12.30
E)2.30

Question 51

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 400.0 mL of KOH.The K_a of HF is 3.5 × 10^-4.

A)13.08
B)12.60
C)13.85
D)12.30
E)12.78

Question 52

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

Question 53

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 100.0 mL of KOH.The K_a of HF is 3.5 × 10^-4.

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

Question 54

Which of the following compounds will be more soluble in acidic solution than in pure water?

A)PbCl₂
B)FeS
C)Ca(ClO₄)₂
D)CuI
E)None of the above will be more soluble in acidic solution.

Question 55

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 200.0 mL of KOH.The K_a of HF is 3.5 × 10^-4.

A)9.62
B)7.00
C)3.46
D)10.54
E)8.14

Question 56

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

Question 57

Give the expression for the solubility product constant for PbCl₂.

A)
B)
C)[Pb²⁺][Cl⁻]²
D)
E)[Pb²⁺]²[Cl⁻]

Question 58

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 200.0 mL of HNO₃.The K_b of NH₃ is 1.8 × 10^-5.

A)6.44
B)1.48
C)2.00
D)12.52
E)12.00

Question 59

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 300.0 mL HBr.

A)1.60
B)1.30
C)1.00
D)12.40
E)1.12

Question 60

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 200.0 mL HBr.

A)2.62
B)2.00
C)1.48
D)12.52
E)7.00

Question 61

The molar solubility of ZnS is 1.6 × 10^-12 M in pure water.Calculate the K_sp for ZnS.

A)8.0 × 10^-13
B)3.2 × 10^-12
C)1.6 × 10^-35
D)2.6 × 10^-24
E)6.80 × 10^-5

Question 62

Determine the molar solubility of CuCl in a solution containing 0.050 M KCl.K_sp (CuCl)= 1.0 × 10^-6.

A)1.0 × 10^-12 M
B)5.0 × 10^-7 M
C)2.0 × 10^-5 M
D)1.0 × 10^-3 M
E)0.050 M

Question 63

Determine the molar solubility of Fe(OH)₂ in pure water.K_sp (Fe(OH)₂)= 4.87 × 10^-17.

A)2.44 × 10^-17 M
B)1.62 × 10^-17 M
C)4.03 × 10^-9 M
D)3.65 × 10^-6 M
E)2.30 × 10^-6 M

Question 64

Give the equation for an unsaturated solution in comparing Q with K_sp.

A)Q > K_sp
B)Q < K_sp
C)Q = K_sp
D)Q ≠ K_sp
E)None of the above.

Question 65

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

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

Question 66

Give the expression for the solubility product constant for BaF₂.

A)
B)
C)[Ba²⁺]²[F⁻]
D)[Ba²⁺][F⁻]²
E)[Ba²⁺][F⁻]

Question 67

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

A)Q > K_sp
B)Q < K_sp
C)Q = K_sp
D)Q ≠ K_sp
E)None of the above.

Question 68

Calculate the Ksp of Fe₂S₃ in pure water.The molar solubility is 1.05 × 10^-18.

A)7.00 × 10^-88
B)1.28 × 10^-90
C)1.40 × 10^-88
D)6.30 × 10^-18
E)exceeds ability of calculator

Question 69

The molar solubility of Ag₂S is 1.26 × 10^-16 M in pure water.Calculate the K_sp for Ag₂S.

A)1.59 × 10^-32
B)1.12 × 10^-8
C)6.81 × 10^-63
D)3.78 × 10^-12
E)8.00 × 10^-48

Question 70

Determine the molar solubility of BaF₂ in pure water.K_sp (BaF₂)= 2.45 × 10^-5.

A)1.83 × 10^-2 M
B)1.23 × 10^-5 M
C)2.90 × 10^-2 M
D)4.95 × 10^-3 M
E)6.13 × 10^-6 M

Question 71

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

A)2.3 × 10^-5 M
B)8.5 × 10^-7 M
C)1.2 × 10^-2 M
D)0.0750 M
E)3.0 × 10^-4 M

Question 72

Determine the molar solubility of AgI in pure water.K_sp (AgI)= 8.51 × 10^-17.

A)9.22 × 10^-9 M
B)4.26 × 10^-17 M
C)8.51 × 10^-17 M
D)2.77 × 10^-6 M
E)4.40 × 10^-6 M

Question 73

Give the expression for the solubility product constant for Cr₂(CO₃)₃.

A)[Cr³⁺]²[CO₃^2-]³
B)
C)
D)
E)[Cr³⁺]³[CO₃^2-]²

Question 74

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

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 75

The molar solubility of CuI is 2.26 × 10^-6 M in pure water.Calculate the K_sp for CuI.

A)5.11 × 10^-12
B)4.52 × 10^-6
C)1.50 × 10^-3
D)4.62 × 10^-17
E)1.02 × 10^-11

Question 76

Determine the molar solubility of CaSO₄ in a solution containing 0.100 M Na₂SO₄.
K_sp (CaSO₄)= 2.4 × 10^-5.

A)4.9 × 10^-3 M
B)2.4 × 10^-4 M
C)5.8 × 10^-10 M
D)1.2 × 10^-5 M
E)0.10 M

Question 77

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

A)
B)
C)
D)[Ca²⁺]²[PO₄^3-]³
E)[Ca²⁺]³[PO₄^3-]²

Question 78

Which of the following compounds will have the highest molar solubility in pure water?

A)PbS,K_sp = 9.04 × 10^-29
B)CuS,K_sp = 1.27 × 10^-36
C)Al(OH)₃,K_sp = 3 × 10^-34
D)ZnS,K_sp = 1.6 × 10^-24
E)Ag₂S,K_sp = 8 × 10^-48

Question 79

Determine the molar solubility of PbSO₄ in pure water.K_sp (PbSO₄)= 1.82 × 10^-8.

A)1.82 × 10^-8 M
B)1.35 × 10^-4 M
C)9.1 × 10^-9 M
D)3.31 × 10^-16 M
E)4.48 × 10^-4 M

Question 80

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

A)8.8 × 10^-7 M
B)3.9 × 10^-13 M
C)5.8 × 10^-5 M
D)5.1 × 10^-12 M
E)0.150 M