Competitive Exams: Chemistry MCQs (Practice-Test 18 of 31)

  1. Which of the following contains TWO anions that form soluble salts with most metal ions and TWO anions that form insoluble salts with most metal ions?

    1. Sulfate, hydroxide, chromate, sulfide

    2. Nitrate, hydroxide, chromate, sulfide

    3. Chloride, hydroxide, chromate, sulfide

    4. Nitrate, chloride, hydroxide, sulfide

  2. Consider an aqueous solution that contains 0.10 M each of Pb2 +, Hg2 + and Ni2 +. If a solution containing 2.0 × 10 − 20 M S2-is added to the solution containing the metal ions, which sulfides will precipitate from the solution? PbS: Ksp = 8.0 × 10 − 28; HgS: Ksp = 4 × 10 − 53; NiS: Ksp = 3.2 × 10 − 19

    1. PbS, HgS and NiS

    2. PbS and HgS

    3. HgS and NiS

    4. NiS only

    5. HgS only

  3. How much (in g) barium sulfate (BaSO4, MW = 233.39) will dissolve in 500 mL of water. For BaSO4: Ksp = 1.1 × 10 − 10.

  4. Which anions below are expected to form soluble salts with all metal ions?

    1. S2-, OH-, NO3-

    2. S2-, Cl-, NO3-

    3. NO3-, ClO3-, ClO4-

    4. CO32-, PO43-, S2-

    5. No response is correct.

  5. Which anions below are expected to form insoluble compounds with most metal ions except alkali metal ions and ammonium ion?

    1. S2-, OH-, NO3-

    2. S2-, Cl-, NO3-

    3. NO3-, ClO3-, ClO4-

    4. CO32-, PO43-, S2-

    5. No response is correct.

  6. Which of the following salts is the most soluble in pure water?

    1. AgBr: Ksp = 7.7 × 10 − 13

    2. AgI: Ksp = 8.3 × 10 − 17

    3. AgCl: Ksp = 1.6 × 10 − 10

    4. SrSO4: Ksp = 3.8 × 10 − 7

    5. More information is needed to answer the question.

  7. Addition of solid silver sulfate (Ag2SO4, Ksp = 1.4 × 10 − 5) to a solution that is already saturated in silver sulfate will cause:

    1. no change in Ag + or SO42-concentrations.

    2. more silver sulfate to dissolve.

    3. some silver sulfate to precipitate from solution.

    4. the silver ion concentration to increase and the sulfate ion concentration to decrease.

    5. No response is correct.

  8. The solubility of silver chromate (Ag2CrO4) in water is 1.3 × 10 − 4 mol/L; what is the solubility product constant for silver chromate?

  9. Calculate the solubility of Ag4 (FeCN) 6 in water assuming no other interfering equilibria. Ag4Fe (CN) 6 ⇔ 4 Ag + + Fe (CN) 64-, Ksp = 1.6 × 10 − 41

  10. Calculate the solubility of aluminum hydroxide (Al (OH) 3, Ksp = 1.0 × 10 − 33) in a solution buffered at pH 11.

  11. What hydroxide ion concentration would be required to start precipitation of manganese hydroxide from a solution that is 0.0031 mol/L in Mn2 +. For Mn (OH) 2, Ksp = 4.6 × 10 − 14.

  12. Milk of magnesia consists of gelatinous Mg (OH) 2 (s) and a small amount of water saturated with Mg (OH) 2. Calculate the pH of the milk of magnesia found in the drug store. Ksp (Mg (OH) 2) = 8.9 × 10 − 12. You may neglect the dissociation of water.

  13. Gastric juice (i.e.. the digestive juice found in our stomach) has a pH of approximately 1.4. Would you expect the solid Mg (OH) 2found in milk of magnesia to be more soluble in gastric juice or in pure water?

  14. Consider a saturated solution of silver bromide, AgBr. If more solid silver bromide were added to this saturated solution, describe what will happen to:

    1. the concentration of Ag +.

    2. the concentration of Br-.

    3. the solubility of AgBr.