Chem2 Ch15

A solution containing CaCl 2 is mixed with a solution of Li 2C 2O 4 to form a solution that is 3.5 × 10 -4 M in calcium ion and 2.33 × 10 -4 M in oxalate ion. What will happen once these solutions are mixed? K sp (CaC 2O 4) = 2.3 × 10 -9. -Nothing will happen Ksp > Q for all possible precipitants. -A precipitate will form as calcium oxalate is not soluble to any extent. -A precipitate will form since Q > Ksp for calcium oxalate. -Nothing will happen since both calcium chloride and lithium oxalate are soluble compounds. -There is not enough information to determine.

-A precipitate will form since Q > Ksp for calcium oxalate.

When titrating a weak monoprotic acid with NaOH at 25°C, the -pH will be less than 7 at the equivalence point. -pH will be greater than 7 at the equivalence point. -pH will be equal to 7 at the equivalence point. -titration will require more moles of base than acid to reach the equivalence point. -titration will require more moles of acid than base to reach the equivalence point.

-pH will be greater than 7 at the equivalence point.

What is the molar solubility of AgCl in 0.10 M NaCN if the colorless complex ion Ag(CN) 2 - forms? K sp for AgCl is 1.8 × 10 -10 and K f for Ag(CN) 2 - is 1.0 × 10 21. 0.050 M 0.10 M 0.40 M 0.20 M

0.050 M

Formic acid (HCO 2H, K a = 1.8 × 10 -4) is the principal component in the venom of stinging ants. What is the molarity of a formic acid solution if 25.00 mL of the formic acid solution requires 29.80 mL of 0.0567 M NaOH to reach the equivalence point? 0.0676 M 0.0134 M 0.0567 M 0.0476 M

0.0676 M

Calculate the percent ionization of nitrous acid in a solution that is 0.222 M in nitrous acid and 0.278 M in potassium nitrite (KNO 2). The acid dissociation constant of nitrous acid is 4.5 x 10^-4 15.5 0.162 3.448 2.78 × 10-3 55.6

0.162

What is the [CH 3CO 2-]/[CH 3CO 2H] ratio necessary to make a buffer solution with a pH of 4.34? K a = 1.8 × 10 -5 for CH 3CO 2H. 2.5:1 0.91:1 1.09:1 0.39:1

0.39:1

You wish to prepare an HC 2H 3O 2 buffer with a pH of 4.34. If the pK a of is 4.74, what ratio of C 2H 3O 2 /HC 2H 3O 2 must you use? 4.0 0.40 0.10 0.40 2.51

0.40

A 100.0 mL sample of 0.18 M HClO 4 is titrated with 0.27 M LiOH. Determine the pH of the solution before the addition of any LiOH. 0.57 1.74 1.57 0.74 1.05

0.74

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 M HCl to reach the equivalence point? 0.800 M 1.30 M 0.312 M 0.300 M

0.800 M

Determine the molar solubility of Al(OH) 3 in a solution containing 0.0500 M AlCl 3. K sp (Al(OH) 3) = 1.3 × 10 -33. 1.04 x 10-29 M 2.6 x 10-9M 2.6 x 10-32 M 6.5 x 10-35 M 5.2 x 10-31 M

1.04 x 10-29 M

Determine the molar solubility of PbSO 4 in pure water. K sp (PbSO 4) = 1.82 × 10 -8. 9.1 × 10-9 M 4.48 × 10-4 M 1.35 × 10-4 M 3.31 × 10-16 M 1.82 × 10-8 M

1.35 × 10 -4 M

A 100.0 mL sample of 0.10 M NH 3 is titrated with 0.10 M HNO 3. Determine the pH of the solution after the addition of 200.0 mL of HNO 3. The K b of NH 3 is 1.8 × 10 -5. 12.52 1.48 6.44 12.00 2.00

1.48

A 100.0 mL sample of 0.18 M HClO 4 is titrated with 0.27 M LiOH. Determine the pH of the solution after the addition of 50.0 mL of LiOH. 12.48 3.22 2.35 1.52 0.68

1.52

What is the molar solubility of AgCl in 0.30 M NH 3? K sp for AgCl is 1.8 x 10^-10 and K f for Ag(NH 3) 2 + is 1.7 x 10^7 1.3 × 10-5 M 1.6 × 10-2 M 5.5 × 10-2 M 1.7 × 10-2 M

1.6 × 10-2 M

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. 1.60 1.12 12.40 1.30 1.00

1.60

Determine the molar solubility of CuCl in a solution containing 0.060 M KCl. K sp (CuCl) = 1.0 × 10 -6. 1.0 × 10-3 M 1.7 × 10-5 M 1.0 × 10-12 M 0.050 M 6.0 × 10-8 M

1.7 × 10-5 M

A 100.0 mL sample of 0.10 M NH 3 is titrated with 0.10 M HNO 3. Determine the pH of the solution after the addition of 150.0 mL of HNO 3. The K b of NH 3 is 1.8 × 10 -5. 2.30 6.44 12.30 7.56 1.70

1.70

Determine the molar solubility of BaF 2 in pure water. K sp for BaF 2 = 2.45 × 10 -5. 1.83 × 10-2 M 1.23 × 10-5 M 6.13 × 10-6 M 2.90 × 10-2 M 4.95 × 10-3 M

1.83 × 10-2 M

A solution contains 2.2 × 10 -3 M in Cu 2+ and 0.33 M in LiCN. If the K f for Cu(CN) 4 2- is 1.0 × 10 25, how much copper ion remains at equilibrium? 3.8 × 10-24 M 6.7 × 10-28 M 2.9 × 10-27 M 4.6 × 10-25 M 1.9 x 10-26 M

1.9 x 10-26 M

What is the molar solubility of magnesium carbonate ( MgCO 3 ) in water? The solubility-product constant for MgCO 3 is 3.5 × 10 -8 at 25°C. 7.46 1.8 × 10-8 1.9 × 10-4 7.0 × 10-8 2.6 × 10-4

1.9 × 10-4

Determine the molar solubility for Zn(OH) 2 in pure water. Ksp for Zn(OH) 2 is 3.00 x 10 -17. 3.0 x 10-17 M 5.5 x 10-19 M 7.5 x 10-18 M 1.96 x 10-6 M 3.11 x 10-6 M

1.96 x 10-6 M

The highest pH for an effective buffer occurs when the base is how many times as concentrated as the acid? 8 5 10 25 40

10

What is the pH of a solution prepared by mixing 50.00 mL of 0.10 M NH 3 with 5.00 mL of 0.10 M NH 4Cl? Assume that the volume of the solutions are additive and that K b = 1.8 × 10 -5 for NH 3. 11.13 9.28 10.26 8.25

10.26

What is the pH of a solution prepared by mixing 50.00 mL of 0.10 M methylamine, CH 3NH 2, with 20.00 mL of 0.10 M methylammonium chloride, CH 3NH 3Cl? Assume that the volume of the solutions are additive and that K b = 3.70 × 10 -4 for methylamine. 10.57 10.97 11.78 10.17

10.97

A 100.0 mL sample of 0.10 M NH 3 is titrated with 0.10 M HNO 3. Determine the pH of the solution before the addition of any HNO 3. The K b of NH 3 is 1.8 × 10 -5. 4.74 13.00 12.55 9.26 11.13

11.13

What is the pH of the resulting solution if 45 mL of 0.432 M methylamine, CH 3NH 2, is added to 15 mL of 0.234 M HCl? Assume that the volumes of the solutions are additive. K a = 2.70 × 10 -11 for CH 3NH 3 +. 9.91 4.09 2.77 11.23

11.23

A 25.0 mL sample of 0.150 M hypochlorous 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 hypochlorous acid is 3.0 × 10 -8. 2.54 7.54 11.47 7.00 7.51

11.47

A 100.0 mL sample of 0.180 M HClO 4 is titrated with 0.270 M LiOH. Determine the pH of the solution after the addition of 75.0 mL of LiOH. 2.65 1.89 11.35 13.06 12.1

12.1

What is the pH of a solution made by mixing 30.00 mL of 0.10 M acetic acid with 50.00 mL of 0.100 M KOH? Assume that the volumes of the solutions are additive. K a = 1.8 × 10 -5 for CH3CO2H 9.26 11.13 12.40 8.26

12.40

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. 1.27 7.00 12.73 2.27 11.73

12.73

What is the pH of a solution prepared by mixing 100.00 mL of 0.020 M Ca(OH) 2 with 50.00 mL of 0.300 M NaOH? Assume that the volumes are additive. 13.10 13.58 13.05 13.28

13.10

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. 1.00 12.86 0.70 13.00 13.30

13.30

Determine the molar solubility of Fe(OH) 2 in pure water. K sp for Fe(OH) 2= 4.87 × 10 -17. 4.03 × 10-9 M 2.44 × 10-17 M 1.62 × 10-17 M 3.65 × 10-6 M 2.30 × 10-6 M

2.30 × 10-6 M

Calculate the solubility (in g/L) of calcium fluoride in water at 25°C if the K sp for is 1.5 × 10 -10. 9.6 × 10-4 g/L 2.6 × 10-2 g/L 3.3 × 10-2 g/L 4.1 × 10-2 g/L

2.6 × 10-2 g/L

The molar solubility of ZnS is 1.6 × 10 -12 M in pure water. Calculate the K sp for ZnS. 8.0 × 10-13 6.80 × 10-5 1.6 × 10-35 3.2 × 10-12 2.6 × 10-24

2.6 × 10-24

Determine the molar solubility of MgCO 3 in pure water. K sp (MgCO 3) = 6.82 × 10 -6. 3.25 × 10-4 M 3.41 × 10-6 M 4.65 × 10-3 M 2.61 × 10-3 M 6.82 × 10-6 M

2.61 × 10-3 M

A 25.0-mL sample of 0.150 M butanoic acid is titrated with a 0.150 M NaOH solution. What is the pH before any base is added? The K a of butanoic acid is 1.5 × 10 -5. 1.5 × 10-3 1.0 × 104 2.83 4.00 4.82

2.83

How many milliliters of 0.0850 M NaOH are required to titrate 25.0 mL of 0.0720 M HBr to the equivalence point? 3.92 21.2 29.5 0.245 0.153

21.2

A solution contains 0.021 M Cl and 0.017 M I . A solution containing copper (I) ions is added to selectively precipitate one of the ions. At what concentration of copper (I) ion will a precipitate begin to form? What is the identity of the precipitate? K sp(CuCl) = 1.0 × 10 -6, K sp(CuI) = 5.1 × 10 -12. 3.0 × 10-10 M, CuI 3.0 × 10-10 M, CuCl 4.8 × 10-5 M, CuI 4.8 × 10-5 M, CuCl No precipitate will form at any concentration of copper (I).

3.0 × 10-10 M, CuI

Determine the molar solubility of BaF 2 in a solution containing 0.0750 M LiF. K sp (BaF 2) = 1.7 × 10 -6. 8.5 × 10-7 M 3.0 × 10-4 M 0.0750 M 1.2 × 10-2 M 2.3 × 10-5 M

3.0 × 10-4 M

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 Ka for HF is 3.5 × 10 -4. 3.82 2.78 4.11 3.46 3.09

3.09

Calculate the pH of a buffer that is 0.060 M HF and 0.030 M KF. The K a for HF is 3.5 × 10 -4. 3.56 3.16 3.76 2.06 4.86

3.16

Calculate the pH of a buffer that is 0.032 M HF and 0.032 M NaF. The K a for HF is 3.5 × 10 -4. 4.79 3.46 10.54 9.31 2.86

3.46

Calculate the pH of a solution formed by mixing 250.0 mL of 0.15 M HCHO 2 with 100.0 mL of 0.20 M LiCHO 2. The K a for HCHO 2 is 1.8 × 10 -4. 10.13 10.53 3.74 3.87 3.47

3.47

Calculate the pH of a solution that is 0.210 M in nitrous acid (HNO 2) and 0.290 M in potassium nitrite (KNO 2). The acid dissociation constant of nitrous acid is 4.50 × 10 -4. 3.210 3.487 4.562 10.51 13.86

3.487

What is the pH of a buffer solution that is 0.211 M in lactic acid and 0.111 M in sodium lactate? The K a of lactic acid is 1.4 × 10 -4. 14.28 4.13 10.43 3.57 5.48

3.57

A solution contains 0.036 M Cu 2+ and 0.044 M Fe 2+. A solution containing sulfide ions is added to selectively precipitate one of the metal ions from solution. At what concentration of sulfide ion will a precipitate begin to form? What is the identity of the precipitate? K sp(CuS) = 1.3 × 10 -36, K sp(FeS) = 6.3 × 10 -18. 1.4 × 10-16 M, CuS 1.4 × 10-16 M, FeS 3.6 × 10-35 M, FeS 3.6 × 10-35 M, CuS No precipitate will form at any concentration of sulfide ion.

3.6 × 10-35 M, CuS

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 0.100 moles of solid NaOH. Assume no volume change upon the addition of base. The K a for HF is 3.5 × 10 -4. 3.22 3.09 3.69 4.46 3.82

3.69

What is the pH of a solution prepared by mixing 25.00 mL of 0.10 M CH 3CO 2H with 25.00 mL of 0.010 M CH 3CO 2Na? Assume that the volume of the solutions are additive and that K a = 1.8 × 10 -5 for CH 3CO 2H. 3.74 5.74 2.87 4.75

3.74

Calculate the pH of a buffer that is 0.020 M HF and 0.040 M NaF. The K a for HF is 3.5 × 10 -4. 3.76 3.36 3.16 2.06 4.86

3.76

Determine the molar solubility of AgBr in a solution containing 0.200 M NaBr. K sp (AgBr) = 7.7 × 10 -13. 1.54 × 10-13 M 8.8 × 10-7 M 3.8 × 10-12 M 5.8 × 10-5 M 0.200 M

3.8 × 10-12 M

Calculate the K sp for zinc hydroxide if the solubility of Zn (OH) 2 in pure water is 2.1 × 10 -4 g/L. 3.8 × 10-17 9.9 × 10-18 2.9 × 10-3 1.5 × 10-3

3.8 × 10-17

A 1.00 L buffer solution is 0.150 M in HC 7H 5O 2 and 0.250 M in LiC 7H 5O 2. Calculate the pH of the solution after the addition of 100.0 mL of 1.00 M HCl. The K a for HC 7H 5O 2 is 6.5 × 10 -5. 3.34 5.03 3.97 4.41 4.19

3.97

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. 3.46 4.24 3.63 2.85 4.06

4.06

Calculate the molar solubility of thallium chloride in 0.40 M NaCl at 25°C. K sp for TlCl is 1.3 × 10-2 M 8.2 × 10-3 M 6.8 × 10-5 M 4.2 × 10-4 M

4.2 × 10-4 M

Calculate the percent ionization of nitrous acid in a solution that is 0.249 M in nitrous acid. The acid dissociation constant of nitrous acid is 4.5 x 10^-4 0.342 0.0450 1.12 × 10-4 5.53 4.25

4.25

Calculate the pH of a solution formed by mixing 150.0 mL of 0.10 M HC 7H 5O 2 with 100.0 mL of 0.30 M NaC 7H 5O 2. The K a for HC 7H 5O 2 is 6.5 × 10 -5. 4.31 9.69 10.51 4.49 4.19

4.49

Calculate the pH of a buffer that is 0.225 M HC 2H 3O 2 and 0.162 M KC 2H 3O 2. The K a for HC 2H 3O 2 is 1.8 × 10 -5. 4.74 4.89 4.60 9.11 9.26

4.60

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 13.3 mL of base is added? The K a of hydrazoic acid is 1.9 × 10 -5. 4.78 1.34 3.03 4.45 4.66

4.78

Calculate the pH of a buffer that is 0.145 M HC 2H 3O 2 and 0.202 M KC 2H 3O 2. The K a for HC 2H 3O 2 is 1.8 × 10 -5. 4.89 9.01 4.60 5.05 4.74

4.89

The molar solubility of CuI is 2.26 × 10 -6 M in pure water. Calculate the K sp for CuI. 4.52 × 10-6 4.62 × 10-17 1.02 × 10-11 5.11 × 10-12 1.50 × 10-3

5.11 × 10-12

The molar solubility of Ba 3(PO 4) 2 is 8.89 x 10 -9 M in pure water. Calculate the K sp for Ba 3(PO 4) 2. 8.16 x 10-31 5.33 x 10-37 4.94 x 10-49 5.55 x 10-41 6.00 x 10-39

6.00 x 10-39

Determine the molar solubility for Pb 3(PO 4) 2 in pure water. Ksp for Pb 3(PO 4) 2 is 1.0 x 10 -54. 5.8 x 10-10 M 1.1 x 10-11 M 4.1 x 10-28 M 1.0 x 10-54 M 6.2 x 10-12 M

6.2 x 10-12 M

A 100.0 mL sample of 0.18 M HClO 4 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). 0.97 2.76 11.24 7.00 13.03

7.00

Calculate the pH of a solution formed by mixing 200.0 mL of 0.30 M HClO with 100.0 mL of 0.20 M KClO. The K a for HClO is 2.9 × 10 -8. 7.54 8.01 5.99 7.06 6.46

7.06

Calculate the pH of a buffer that is 0.94 M HClO and 0.059 M NaClO. The K a for HClO is 2.9 × 10 -8. 7.34 6.36 7.54 7.74 6.67

7.34

Identify the pH of normal blood. 7.2 7.4 7.6 7.8 6.9

7.4

What is the molar solubility of barium fluoride ( BaF 2 ) in water? The solubility-product constant for BaF 2 is 1.7 × 10 -6 at 25 degrees celsius 1.2 × 10-2 1.8 × 10-3 7.5 × 10-3 6.5 × 10-4 5.7 × 10-7

7.5 × 10-3

Calculate the pH of a solution formed by mixing 200.0 mL of 0.30 M HClO with 300.0 mL of 0.20 M KClO. The K a for HClO is 2.9 × 10 -8. 5.99 8.01 7.54 6.46 7.06

7.54

What is the pH of a buffer solution that is 0.255 M in hypochlorous acid (HClO) and 0.333 M in sodium hypochlorite? The K a of hypochlorous acid is 3.8 × 10 -8. 6.46 13.88 7.30 8.49 7.54

7.54

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. 7.06 7.54 5.99 6.46 8.01

8.01

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 M NaOH? K a = 6.76 × 10 -4 for HF. 12.26 8.25 1.74 5.75

8.25

What is the approximate pH at the equivalence point of a weak acid-strong base titration if 25 mL of aqueous formic acid requires 29.80 mL of 0.3567 M NaOH? K a =1.8 × 10 -4 for formic acid. 5.48 8.52 2.06 11.94

8.52

Calculate the pH of a solution formed by mixing 250.0 mL of 0.15 M NH 4Cl with 100.0 mL of 0.20 M NH 3. The K b for NH 3 is 1.8 x 10 -5. 9.53 8.98 9.25 9.13 4.74

8.98

Calculate the pH of a solution formed by mixing 250.0 mL of 0.15 M NH 4Cl with 200.0 mL of 0.12 M NH 3. The K b for NH 3 is 1.8 × 10 -5. 4.74 9.26 9.45 4.55 9.06

9.06

A solution contains 3.8 × 10 -2 M in Al 3+ and 0.29 M in NaF. If the K f for AlF 6 3- is 7 × 10 19, how much aluminum ion remains at equilibrium? 1.9 × 10-21 M 1.1 × 10-19 M 9.1 × 10-19 M 3.1 × 10-22 M 4.4 × 10-20 M

9.1 × 10-19 M

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

A buffer is most resistant to pH change when [acid] = [conjugate base]

A solution containing CaCl 2 is mixed with a solution of Li 2C 2O 4 to form a solution that is 3.5 × 10 -4 M in calcium ion and 2.33 × 10 -4 M in oxalate ion. What will happen once these solutions are mixed? K sp (CaC 2O 4) = 2.3 × 10 -9. Nothing will happen Ksp > Q for all possible precipitants. A precipitate will form as calcium oxalate is not soluble to any extent. A precipitate will form since Q > Ksp for calcium oxalate. Nothing will happen since both calcium chloride and lithium oxalate are soluble compounds. There is not enough information to determine.

A precipitate will form since Q > Ksp for calcium oxalate.

Which of the following solutions is a good buffer system? A solution that is 0.10 M NaOH and 0.10 M HNO3 A solution that is 0.10 M NaCl and 0.10 M HCl A solution that is 0.10 M HCN and 0.10 M LiCN A solution that is 0.10 M HCN and 0.10 M KI A solution that is 0.10 M HNO3 and 0.10 M NaNO3

A solution that is 0.10 M HCN and 0.10 M LiCN

A sample contains Ba 3(PO 4) 2, CdS, AgCl, NH 4Cl, and ZnS. Identify the precipitate after the addition of 6 M HCl. NiS Ca3(PO4)2 HgS AgCl NH4Cl

AgCl

Which of the following compounds solubility will not be affected by a low pH in solution? AgCl CuS CaF2 SrCO3 Sr(OH)2

AgCl

Gives what happens at high pH for aluminum hydroxide. Al dissolves Al(H2O)2(OH)4- dissolves Al(H2O)33+ precipitates Al(OH)5 dissolves Al precipitates

Al(H2O)2(OH)4- dissolves

Gives what happens at low pH for aluminum hydroxide. Al(H2O)4(OH)2- precipitates Al(H2O)63+ dissolves Al dissolves Al(OH)3 precipitates Al precipitates

Al(H2O)63+ dissolves

Gives what happens at neutral pH for aluminum hydroxide. Al(H2O)63+ precipitates Al(OH)3 precipitates Al precipitates Al dissolves Al(H2O)2(OH)4- dissolves

Al(OH)3 precipitates

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. 12.70 2.00 1.30 12.00 7.00

Balanced equation Ca(OH)2 + 2 HBr ------> CaBr2 + 2 H2O Moles of Ca(OH)2 = molarity x volume = 0.1 L x 0.1 M = 0.01 mol moles of HBr = 0.1 L x 0.1M = 0.01 mol From the stoichiometry of the reaction 2 moles of HBr reacts with = 1 mole Ca(OH)2 Moles of HBr required = 2*0.01 = 0.02 mol total volume = 200 mL = 0.20 L M HBr = 0.02 moles HBr/0.20 L= 0.1 M pH=-log[H+] pH= -log[0.1] pH = 1 pH= 1.4

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. 1.00 1.30 1.40 1.22 2.11

Ca(OH)2 + 2 HBr => CaBr2 + 2 H2O Initial moles of Ca(OH)2 = 100.0/1000 x 0.10 = 0.01 mol Initial moles of HBr = 400.0/100 x 0.10 = 0.04 mol Moles of HBr reacted = 2 x moles of Ca(OH)2 = 2 x 0.01 = 0.02 mol Excess moles of HBr = 0.04 - 0.02 = 0.02 mol Total volume = 100 + 400 = 500 mL = 0.500 L [H+] = moles of excess HBr/total volume = 0.02/0.500 = 0.04 M pH = -log[H+] = -log(0.04) = 1.40

Which of the following compounds will have the highest molar solubility in pure water? ZnS, Ksp = 2.0 × 10-25 CuS, Ksp = 1.27 × 10-36 HgS, Ksp = 1.6 × 10-54 Fe(OH)3, Ksp = 2.79 × 10-39 Ag2S, Ksp = 6.0 × 10-51

Fe(OH)3, Ksp = 2.79 × 10-39

Which of the following compounds will be more soluble in acidic solution than in pure water? Ca(ClO4)2 FeS PbBr2 CuI None of the above will be more soluble in acidic solution.

FeS

A 100.0 mL sample of 0.18 M HClO 4 is titrated with 0.27 M LiOH. Determine the pH of the solution after the addition of 30.0 mL of LiOH. 1.12 1.21 0.86 2.00 2.86

HClO4 LiOH MA = 0.18M MB = 0.27M VA = 100ml VB = 30ml M =[H+] = MAVA - MBVB/VA+ VB = 0.18*100-0.27*30/100+30 = 9.9/130 = 0.076M PH = -log[H+] = -log0.076 = 1.119 >>>>>> answer

A ligand is a molecule or ion that acts as a Lewis base Brønsted-Lowry base conjugate base Lewis acid Arrhenius base

Lewis base

Which of the following compounds will have the highest molar solubility in pure water? AgCN, Ksp = 5.97 × 10-17 MgCO3, Ksp = 6.82 × 10-6 PbSO4, Ksp = 1.82 × 10-8 NiS, Ksp = 3.00 × 10-20 PbS, Ksp = 9.04 × 10-29

MgCO3, Ksp = 6.82 × 10-6

A sample contains Ba 3(PO 4) 2, CdS, AgCl, NH 4Cl, and ZnS. Identify the precipitate after the addition of 6 M HCl; H 2S and 0.2 M HCl; and OH - to a pH of 8. Ba3(PO4)2 MnS NH4Cl HgS AgCl

MnS

A 100.0 mL sample of 0.10 M NH 3 is titrated with 0.10 M HNO 3. Determine the pH of the solution after the addition of 50.0 mL of HNO 3. The K b of NH 3 is 1.8 × 10 -5. 7.05 9.26 7.78 10.34 4.74

Molarity of HNO3 = 0.1 M Volume of HNO3 = 50 mL Molarity of NH3 = 0.1 M Volume of NH3 = 100 mL mol of HNO3 = Molarity of HNO3 * Volume of HNO3 mol of HNO3 = 0.1 M * 50 mL = 5 mmol mol of NH3 = Molarity of NH3 * Volume of NH3 mol of NH3 = 0.1 M * 100 mL = 10 mmol We have: mol of HNO3 = 5 mmol mol of NH3 = 10 mmol 5 mmol of both will react excess NH3 remaining = 5 mmol Volume of Solution = 50 + 100 = 150 mL [NH3] = 5 mmol/150 mL = 0.0333 M [NH4+] = 5 mmol/150 mL = 0.0333 M They form basic buffer base is NH3 conjugate acid is NH4+ Kb = 1.8*10^-5 pKb = - log (Kb) = - log(1.8*10^-5) = 4.745 we have below equation to be used: This is Henderson-Hasselbalch equation pOH = pKb + log {[conjugate acid]/[base]} = 4.745+ log {3.333*10^-2/3.333*10^-2} = 4.74 we have below equation to be used: PH = 14 - pOH = 14 - 4.74 = 9.26

A solution containing CaCl 2 is mixed with a solution of Li 2C 2O 4 to form a solution that is 2.1 × 10 -5 M in calcium ion and 4.75 × 10 -5 M in oxalate ion. What will happen once these solutions are mixed? K sp (CaC 2O 4) = 2.3 × 10 -9. Nothing will happen since calcium oxalate is extremely soluble. A precipitate will form since Q > Ksp for calcium oxalate. Nothing will happen since both calcium chloride and lithium oxalate are soluble compounds. Nothing will happen since Ksp > Q for all possible precipitants. There is not enough information to determine.

Nothing will happen since Ksp > Q for all possible precipitants.

Give the equation for an unsaturated solution in comparing Q with K sp. Q ≠ Ksp Q < Ksp Q > Ksp Q = Ksp none of the above

Q < Ksp

Give the equation for a saturated solution in comparing Q with K sp. Q ≠ Ksp Q = Ksp Q < Ksp Q > Ksp none of the above

Q = Ksp

A solution containing AgNO 3 is mixed with a solution of NaCl to form a solution that is 0.10 M in AgNO 3 and 0.075 M in NaCl. What will happen once these solutions are mixed? K sp (AgCl) = 1.77 × 10 -10. Silver chloride will precipitate out of solution, leaving a saturated AgCl solution. Nothing will happen since the molar solubility of AgCl is higher than the solution concentrations. Silver chloride will precipitate out of solution, leaving an unsaturated solution of AgCl. Nothing will happen since NaCl and AgNO3 are both soluble compounds. There is not enough information to say anything about this solution.

Silver chloride will precipitate out of solution, leaving a saturated AgCl solution.

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

The equivalence point is where the amount of acid equals the amount of base during any acid-base titration.

Identify the compound that is base-insoluble. ZnS PbCl2 Ca3(PO4)2 KCl As2S3

ZnS

Give the expression for the solubility product constant for BaF 2. [Ba2+]2[ F] [Ba2+][2F] [Ba2+][F]2

[Ba2+][F]2

Give the expression for the solubility product constant for Ca 3(PO 4) 2. [Ca2+]3[PO43-]2 [ Ca2+]2[ PO43-]3

[Ca2+]3[PO43-]2

If the pKa of HCHO 2 is 3.74 and the pH of an HCHO 2/NaCHO 2 solution is 3.89, which of the following is TRUE? [HCHO2] = [NaCHO2] [HCHO2] < [NaCHO2] [HCHO2] > [NaCHO2] [HCHO2] >> [NaCHO2] It is not possible to make a buffer of this pH from HCHO2 and NaCHO2.

[HCHO2] < [NaCHO2]

If the pKa of HCHO 2 is 3.74 and the pH of an HCHO 2/NaCHO 2 solution is 3.74, which of the following is TRUE? [HCHO2] = [NaCHO2] [HCHO2] < <[NaCHO2] [HCHO2] < [NaCHO2] [HCHO2] > [NaCHO2] It is not possible to make a buffer of this pH from HCHO2 and NaCHO2.

[HCHO2] = [NaCHO2]

If the pKa of HCHO 2 is 3.74 and the pH of an HCHO 2/NaCHO 2 solution is 3.11, which of the following is TRUE? [HCHO2] << [NaCHO2] [HCHO2] < [NaCHO2] [HCHO2] = [NaCHO2] [HCHO2] > [NaCHO2] It is not possible to make a buffer of this pH from HCHO2 and NaCHO2.

[HCHO2] > [NaCHO2]

Give the expression for the solubility product constant for PbCl 2. [Pb2+][Cl-]2 [Pb2+]2[2Cl-]

[Pb2+][Cl-]2

A 1.0 L buffer solution is 0.250 M HC 2H 3O 2 and 0.050 M LiC 2H 3O 2. Which of the following actions will destroy the buffer? adding 0.050 moles of HC2H3O2 adding 0.050 moles of LiC2H3O2 adding 0.050 moles of NaOH adding 0.050 moles of HCl None of the above will destroy the buffer.

adding 0.050 moles of HCl

Identify the indicator that has two endpoints. alizarin yellow R crystal violet phenol red alizarin phenolphthalein

alizarin

Identify the indicator that can be used at the highest pH. alizarin phenolphthalein alizarin yellow R thymol blue crystal violet

alizarin yellow R

Stalactites and stalagmites form as ________ precipitates out of the water evaporating in underground caves. sodium hydroxide hydrochloric acid calcium carbonate sodium bicarbonate sodium chloride

calcium carbonate

An important buffer in the blood is a mixture of ________. acetic acid and carbonate ion hydrochloric acid and sodium hydroxide sodium chloride and hydrochloric acid acetic acid and bicarbonate ion carbonic acid and bicarbonate ion

carbonic acid and bicarbonate ion

Identify the indicator that can be used at the lowest pH. phenolphthalein phenol red thymol blue m-nitrophenol crystal violet

crystal violet

A 100.0 mL sample of 0.18 M HClO 4 is titrated with 0.27 M LiOH. Determine the pH of the solution after the addition of 100.0 mL of LiOH. 12.65 13.13 0.87 12.95 1.35

mmol of acid = MV = 100*0.18 = 18 mmol mmol of base = MV = 100*0.27 = 27 mmol mmol of base left after reaction = 27-18 = 9 [OH-] = mmol/(V1+V2) = 9/(100+100) = 0.045 M pOH = -log(0.045) = 1.34678 pH = 14-1.34678 pH= 12.65322

When titrating a strong monoprotic acid and KOH at 25°C, the -titration will require more moles of acid than base to reach the equivalence point. -pH will be greater than 7 at the equivalence point. -pH will be less than 7 at the equivalence point. -titration will require more moles of base than acid to reach the equivalence point. -pH will be equal to 7 at the equivalence point.

pH will be equal to 7 at the equivalence point.

When titrating a monoprotic strong acid with a weak base at 25°C, the pH will be greater than 7 at the equivalence point. titration will require more moles of acid than base to reach the equivalence point. pH will be less than 7 at the equivalence point. pH will be 7 at the equivalence point. titration will require more moles of the base than acid to reach the equivalence point.

pH will be less than 7 at the equivalence point.

Identify the most common indicator. thymol blue phenolphthalein thymolphthalein crystal violet alizarin

phenolphthalein

Identify a good buffer. small amounts of both a strong acid and a strong base significant amounts of both a weak acid and a strong acid small amounts of both a weak acid and its conjugate base significant amounts of both a strong acid and a strong base significant amounts of both a weak acid and its conjugate base

significant amounts of both a weak acid and its conjugate base

Describe the solubility of Al(OH) 3 with respect to pH. soluble at low pH, insoluble in pH-neutral solution, and insoluble at high pH insoluble at low pH,insoluble in pH-neutral solution, and soluble at high pH soluble at low pH, insoluble in pH-neutral solution, and soluble at high pH insolubleinsoluble at low pH, in pH-neutral solution, and at high pH pH has no effect on the solubility

soluble at low pH, insoluble in pH-neutral solution, and soluble at high pH