Acid Bases

Calculate the pH of a buffer that is 0.105 M HC2H3O2 and 0.146 M KC2H3O2. The Ka for HC2H3O2 is 1.8 x 10-5. A) 4.89 B) 9.11 C) 4.74 D) 9.26 E) 4.60

A) 4.89

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 Kb for NH3 is 1.8 x 10-5. A) 9.06 B) 9.45 C) 4.55 D) 4.74 E) 9.26

A) 9.06

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

A) A solution that is 0.10 M HC2H3O2 and 0.10 M LiC2H3O2

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

A) AgCl

Define buffer capacity. A) Buffer capacity is the amount of acid or base that can be added to a buffer without destroying 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.

A) Buffer capacity is the amount of acid or base that can be added to a buffer without destroying effectiveness.

Identify the salts that are in hard water. A) CaCO3 and MgCO3 B) MgSO4 and CaSO4 C) NaCl and KBr D) NaHSO4 and Na2SO4 E) NaOCland HOCl

A) CaCO3 and MgCO3

Which of the following is TRUE? A) The equivalence point 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

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

Determine the molar solubility of PbSO4 in pure water. Ksp (PbSO4) = 1.82 x 10-8. A) 1.82 x 10-8 M B) 1.35 x 10-4 M C) 9.1 x 10-9 M D) 3.31 x 10-16 M E) 4.48 x 10-4 M

B) 1.35 x 10-4 M

Calculate the pH of a solution that contains 3.9 x 10-4 M H3O+ at 25C. A) 4.59 B) 3.41 C) 10.59 D) 9.41 E) 0.59

B) 3.41

What is the pH of a solution prepared by mixing 25.00 mL of 0.10 M CH3CO2H with 25.00 mL of 0.010 M CH3CO2H Na? Assume that the volume of the solutions are additive and that Ka = 1.8 x 10-5 for CH3CO2H. A) 2.87 B) 3.74 C) 4.75 D) 5.74

B) 3.74

Which of the following is NOT a conjugate acid-base pair? A) NH4+ /NH3 B) H3O+ /OH- C) H2SO3 /HSO3- D) C2H3O2- /HC2H3O2 E) All of the above are conjugate acid-base pairs.

B) H3O+ /OH-

Identify the triprotic acid. A) HNO3 B) H3PO4 C) H2SO3 D) HClO4 E) H2SO4

B) H3PO4

Which of the following compounds will have the highest molar solubility in pure water? A) PbSO4, Ksp = 1.82 x 10-8 B) MgCO3, Ksp = 6.82 x 10-6 C) AgI, Ksp = 8.51 x 10=17 D) PbS, Ksp = 9.04 x 10-29 E) FeS, Ksp = 3.72 x 10-19

B) MgCO3, Ksp = 6.82 x 10-6

Identify the indicator that has two endpoints. A) phenol red B) thymol blue C) crystal violet D) phenolphalein E) alizarian yellow R

B) thymol blue

The base-dissociation constant of ethylamine (C5H5NH2) is 6.4 x 10-4 at 25.0 C. The [H+] in a 1.6 x 10-2 M solution of ethylamine is ________ M. A) 3.5 x 10-12 B) 2.9 x 10-3 C) 3.1 x 10-12 D) 3.2 x 10-3 E) 11.46

C) 3.1 x 10-12

Calculate the pH of a solution that contains 2.4 x 10-5 M H3O+ at 25C. A) 2.40 B) 9.38 C) 4.62 D) 11.60 E) 4.17

C) 4.62

Identify the pH of normal blood. A) 7.0 B) 7.2 C) 7.4 D) 7.6 E) 7.8

C) 7.4

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

C) A buffer resists pH change by neutralizing added acids and bases

Identify the weak diprotic acid. A) HNO3 B) H3PO4 C) H2SO3 D) HClO4 E) H2SO4

C) H2SO3

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

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

Give the expression for the solubility product constant for PbCl2. A) [Pb2+] [Cl-]2 / [PbCl2] B) [PbCl2] / [Pb2+] [Cl-]2 C) [Pb2+] [Cl-]2 D) [Pb2+] [Cl-] / [PbCl2] E) [Pb2+]2 [Cl-]

C) [Pb2+] [Cl-]2

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

C) pH will be greater than 7 at equivalence point

Calculate the pH of a buffer that is 0.058 M HF and 0.058 M LiF. Then Ka for HF is 3.5 x 10-4. A) 2.86 B) 9.31 C) 10.54 D) 3.46 E) 4.69

D) 3.46

Identify the most common indicator. A) Alizarin B) Thymol Blue C) Crystal Violet D) Phenolphthalein E) ALizarin yellow R

D) Phenolphthalein

When titrating a strong monoprotic acid and KOH at 25C, the A) pH will be less than 7 at equivalence point B) pH will be greater than 7 at 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 equivalence point. E) titration will require more mole of acid than base to reach the equivalence point

D) pH will be equal to 7 at equivalence point.

Identify the most common indicator. A) alizarin B) thymol blue C) crystal violet D) phenolphthalein E) alizarin yellow R

D) phenolphthalein

Determine the [OH-] concentration in a 0.235 M NaOH solution. A) 4.25 x 10-14 M B) 0.470 M C) 2.13 x 10-14 M D) 0.198 M E) 0.235 M

E) 0.235 M

Give the characteristics of a strong acid. A) Ionizes completely in aqueous solutions. B) Has a very electronegative atom attached to the oxygen. C) Has a polar bond. D) Has a weaker bond to hydrogen. E) All the above

E) All the above

What is the conjugate acid of HCO3-? A) H3O+ B) H2O C) CO32- D) OH- E) H2CO3

E) H2CO3

Identify the indicator that can be used at the highest pH. A) phenol red B) thymol blue C) crystal violet D) phenolphalein E) alizarian yellow R

E) alizarian yellow R