Chapter 3 - Solubility Practice Test #1

Transcription

1 Chapter 3 - Solubility Practice Test #1 1. Which combination of factors will affect the rate of the following reaction? Zn (s) + 2HCl ZnCl 2 + H 2(g) A. Temperature and surface area only B. Temperature and concentration only C. Concentration and surface area only D. Temperature, concentration, and surface area 2. Consider the following reaction: - 2MnO 4 + 5C 2 O H + 2Mn CO 2(g) + 8H 2 O (l) The rate of decomposition of the oxalate ion is increased by A. Adding NaOH B. Removing CO 2 C. Adding a catalyst D. Decreasing the pressure 3. An equilibrium system shifts left when the temperature is increased. The forward rate is A. Exothermic and H is positive. B. Exothermic and H is negative. C. Endothermic and H is positive. D. Endothermic and H is negative. 4. The value of the Keq can be changed by A. adding a catalyst. B. changing the temperature. C. changing the reactant concentration. D. changing the volume of the container 5. Consider the following equilibrium: 2NOCl (g) 2NO (g) + Cl 2(g) In a 1.0 L container at equilibrium there are 1.0 mol NOCl, 0.70 mol NO and 0.40 mol Cl 2. At constant temperature and volume, 0.10 mol NOCl is added. The concentrations in the new equilibrium in comparison to the concentrations in the old equilibrium are [NOCl] [NO] [Cl 2 ] A new = old new = old new = old B new > old new > old new > old C new < old new < old new > old D new < old new > old new > old 6. The equation that represents the equilibrium in a saturated solution of Fe 2 (SO 4 ) 3 is A. Fe 2 (SO 4 ) 3(s) 3Fe SO 4 3- B. Fe 2 (SO 4 ) 3(s) 2Fe SO 4 3- C. Fe 2 (SO 4 ) 3(s) 3Fe SO 4 D. Fe 2 (SO 4 ) 3(s) 2Fe SO 4 1

2 7. When equal volumes of 0.20 M K 2 CrO 4 and 0.20 M AgNO 3 are mixed, a red precipitate is formed. The net ionic equation for this reaction is A. K NO 3 KNO 3(s) B. 2Ag + + CrO 4 Ag 2 CrO 4(s) C. K 2 CrO 4 + 2AgNO 3 Ag 2 CrO 4(s) + 2KNO 3 D. 2Ag CrO 4 + 2K NO 3 Ag 2 CrO 4(s) + 2KNO 3(s) 8. Which of the following compounds could be used to prepare a 0.20 M solution of hydroxide ion? A. KOH B. Fe(OH) 3 C. Mg(OH) 2 D. Zn(OH) 2 9. When 250 ml of 0.36 M Sr(OH) 2 are added to 750 ml of water, the resulting ion concentrations are A. [Sr 2+ ] = 0.12 M and [OH - ] = 0.12 M B. [Sr 2+ ] = 0.12 M and [OH - ] = 0.24 M C. [Sr 2+ ] = M and [OH - ] = M D. [Sr 2+ ] = M and [OH - ] = M 10. When equal volumes of 2.0 M Pb(NO 3 ) 2 and 2.0 M KCl are mixed, A. a precipitate forms because the trial ion product < K sp B. a precipitate forms because the trial ion product > K sp C. a precipitate does not form because the trial ion product < K sp D. a precipitate does not form because the trial ion product > K sp 11. Consider the following equilibrium: AgCl(s) Ag+ + Cl- When Br - is added to a saturated solution of AgCl, A. more AgCl dissolves and its solubility product increases. B. more AgCl precipitates and its solubility product decreases. C. more AgCl dissolves and its solubility product remains constant. D. more AgCl precipitates and its solubility product remains constant. 12. The molar solubility of iron II sulphide is A. 3.6 x M B. 3.0 x M C. 6.0 x M D. 7.7 x M 13. A solution containing an unknown cation was added to three solutions and the following observations were recorded: Solution NaI Na 2 SO 4 NaOH Observation no precipitate precipitate no precipitate The unknown cation is A. Pb 2+ B. Sr 2+ C. Ca 2+ D. Ag + 2

3 14. If the solubility of Pb(OH) 2 is g/l, then the concentration of each ion in a saturated solution is A. [Pb 2+ ] = g/l and [OH - ] = g/l B. [Pb 2+ ] = g/l and [OH - ] = g/l C. [Pb 2+ ] = 6.43 x 10-4 M and [OH - ] = 1.29 x 10-3 M D. [Pb 2+ ] = 6.43 x 10-4 M and [OH - ] = 6.43 x 10-3 M 15. Which of the following could be used to separate Pb 2+ from Ba 2+ by precipitation? A. Na 2 S B. NaOH C. Na 2 CO 3 D. Na 2 SO When dissolved in water, which of the following form a molecular solution? A. HCl (g) B. NaNO 3(s) C. CH 3 OH (l) D. K 2 SO 4(s) 17. Which of the following will be most soluble in water at 25 o C. A. AgI B. PbS C. MgSO 4 D. Ba(OH) At 25 o C, the solubility of Mg(OH) 2 is A. 1. x M B. 1. x M C. 1. x 10-6 M D. 1. x 10-4 M 19. At 25 o C, the solubility of an unknown compound is 7.1 x 10-5 M. The compound is A. CuI B. AgI C. CaCO 3 D. CaSO When solid AgBr is added to a saturated solution of AgBr, the reaction rates can be described as: Rate of Dissolving Rate of Crystalizing A. increasing increasing B. increasing decreasing C. decreasing increasing D. increasing no change 21. The solubility of PbS is 2.9 x M. What is the value of the Ksp. A. 8.4 x C. 5.8 x B. 2.9 x D. 1.7 x Which of the following causes a precipitate to form when Sr 2+ is added but not when Zn 2+ is added? A. S C. SO 4 B. Cl - D. CO 3 3

4 23. A 3.0 L solution of NiCl 2 is found to have a chloride concentration of 0.60 M. The concentration of nickel II ions is A M B M C M D. 1.2 M 24. When equal volumes of 0.20 M K 2 CO 3 and 0.2 M Na 3 PO 4 are mixed, A. no precipitate will form B. a precipitate of K 3 PO 4 will form C. a precipitate of Na 2 CO 3 will form D. a precipitate of K 3 PO 4 and Na 2 CO 3 will form 25. A solution of AgNO 3 is slowly added to a mixture containing 0.10 M I -, Cl -, Br -, and IO 3 -. The precipitate which forms first is A. AgI B. AgCl C. AgBr D. AgIO Which of the following units can be used to represent solubility? A. g B. mol C. mol/l D. ml/s 27. Consider the following equilibrium: CaCO 3(s) Ca 2+ + CO 3 Which of the following reagents when added to the equilibrium system, would cause more CaCO 3 to dissolve? A. KNO 3(s) B. CaCO 3(s) C. H 2 C 2 O 4(s) D. Na 2 CO 3(s) 28. Which of the following could be used to precipitate both Mg 2+ and Ca 2+ from hard water? A. lithium sulphate B. sodium phosphate C. potassium sulphide D. ammonium chloride 29. What is the maximum [Ag + ] that can exist in 0.20 M NaBrO 3? A. 1.1 x 10-5 M B. 5.3 x 10-5 M C. 2.6 x 10-4 M D. 7.3 x 10-3 M 30. Which of the following ions could be used to separate Cl - from SO 4 by precipitation? A. Ag + B. Ca 2+ C. NH 4 + D. Pb The Ksp expression for a saturated solution Ca 3 (PO 4 ) 2 is A. K sp = [Ca 2+ ][PO 3-4 ] C. K sp = [3Ca 2+ ][2PO 4 B. K sp = [Ca 2+ ] 3 [PO 3-4 ] 2 D. K sp = [3Ca 2+ ][2PO 3-4 ] 3- ] 4

5 32. When Ca(OH) 2 attains solubility equilibrium, the A. solution will be saturated B. ph will be less than 7 C. trial K sp is less than the K sp D. concentrations of the ions are equal 33. Which of the following describes the changes in ion concentrations when 1.0 g of solid ZnS is added to a saturated solution of ZnS? [Zn 2+ ] [S ] A. increases decreases B. decreases decreases C. increases increases D. remains constant remains constant 34. The net ionic equation for the reaction between Sr(OH) 2 and H 2 SO 4 is A. H + + OH - H 2 O B. Sr 2+ + SO 4 SrSO 4 C. Sr(OH) 2 + H 2 SO 4 SrSO 4 + 2H 2 O D. Sr OH - + 2H + + SO 4 SrSO 4 + 2H 2 O 35. The relationship between the solubility and the size of the K sp is A. there is no relationship B. the smaller the K sp the greater the solubility C. the greater the K sp the greater the solubility D. the solubility is always the square root of the K sp 36. Which of the following compounds will form a saturated solution with the greatest concentration of Ag +? A. AgI B. AgBr C. AgIO 3 D. AgBrO When equal volumes of 0.20 M CuSO 4 and 0.20 M Li 2 S are combined, the complete ionic equation is A. Cu 2+ + S CuS (s) B. CuSO 4 + Li 2 S CuS (s) + Li 2 SO 4 C. Cu 2+ + SO 4 + 2Li + + S CuS (s) + Li 2 SO 4 D. Cu 2+ + SO 4 + 2Li + + S CuS (s) + 2Li + + SO Which of the following would have the [Fe 3+ ] = M? A L of M Fe(NO 3 ) 3 C L of M FeC 6 H 5 O 7 B L of M Fe 2 (SO 4 ) 3 D L of M Fe 2 (C 2 O 4 ) 3 5

6 39. A solution contains both Ag + and Mg 2+ ions. During selective precipitation, these ions are removed one at a time by adding A. I - followed by OH - C. SO 4 followed by Cl - B. OH - followed by S D. NO followed by PO The solubility of an AB 2 type salt is 2.3 x 10-6 M. The salt is A. PbBr 2 B. Fe(OH) 2 C. Cu(IO 3 ) 2 D. Mg(OH) 2 1. A saturated solution of BaSO 4 is given to patients needing digestive tract x-rays. a) Write an equation that represents the solubility equilibrium b) Calculate the [Ba 2+ ] present in the saturated solution. 2. Will a precipitate form when 90.0 ml of 1.00 x 10-2 M Cu(NO 3 ) 2 and 10.0 ml of 1.00 x 10-2 M NaIO 3 are mixed? Explain using appropriate calculations. 3. What is the maximum [CO 3 ] that can exist in a 1.3 x 10-4 M AgNO 3 solution? 6

7 4. The following data was collected when a ml sample of water containing chloride ion was titrated using M AgNO 3 to completely precipitate the chloride ion. Initial volume of AgNO 3 Final volume of AgNO ml ml a) Write the net ionic reaction for the precipitation reaction. c) Calculate the [Cl - ]. 5. In an experiment to determine the solubility of BaF 2, ml of the saturated solution was heated in an evaporating dish to remove the water. The evaporating dish and the residue were then heated two more times to ensure all the water was removed. Volume of the saturated solution of BaF 2 Mass of the evaporating dish Mass of the evaporating dish and BaF 2 after the first heating Mass of the evaporating dish and BaF 2 after the second heating Mass of the evaporating dish and BaF 2 after the third heating ml g g g g Using the above data, calculate the Ksp for BaF 2 7

8 Answers 1. Which combination of factors will affect the rate of the following reaction? Zn (s) + 2HCl ZnCl 2 + H 2(g) A. Temperature and surface area only B. Temperature and concentration only C. Concentration and surface area only D. Temperature, concentration, and surface area 2. Consider the following reaction: - 2MnO 4 + 5C 2 O H + 2Mn CO 2(g) + 8H 2 O (l) The rate of decomposition of the oxalate ion is increased by A. Adding NaOH B. Removing CO 2 C. Adding a catalyst D. Decreasing the pressure 3. An equilibrium system shifts left when the temperature is increased. The forward rate is A. Exothermic and H is positive. B. Exothermic and H is negative. C. Endothermic and H is positive. D. Endothermic and H is negative. 4. The value of the Keq can be changed by A. adding a catalyst. B. changing the temperature. C. changing the reactant concentration. D. changing the volume of the container 5. Consider the following equilibrium: 2NOCl (g) 2NO (g) + Cl 2(g) In a 1.0 L container at equilibrium there are 1.0 mol NOCl, 0.70 mol NO and 0.40 mol Cl 2. At constant temperature and volume, 0.10 mol NOCl is added. The concentrations in the new equilibrium in comparison to the concentrations in the old equilibrium are [NOCl] [NO] [Cl 2 ] A new = old new = old new = old B new > old new > old new > old C new < old new < old new > old D new < old new > old new > old 8

9 6. The equation that represents the equilibrium in a saturated solution of Fe 2 (SO 4 ) 3 is A. Fe 2 (SO 4 ) 3(s) 3Fe SO 4 3- B. Fe 2 (SO 4 ) 3(s) 2Fe SO 4 3- C. Fe 2 (SO 4 ) 3(s) 3Fe SO 4 D. Fe 2 (SO 4 ) 3(s) 2Fe SO 4 7. When equal volumes of 0.20 M K 2 CrO 4 and 0.20 M AgNO 3 are mixed, a red precipitate is formed. The net ionic equation for this reaction is A. K NO 3 KNO 3(s) B. 2Ag + + CrO 4 Ag 2 CrO 4(s) C. K 2 CrO 4 + 2AgNO 3 Ag 2 CrO 4(s) + 2KNO 3 D. 2Ag CrO 4 + 2K NO 3 Ag 2 CrO 4(s) + 2KNO 3(s) 8. Which of the following compounds could be used to prepare a 0.20 M solution of hydroxide ion? A. KOH B. Fe(OH) 3 C. Mg(OH) 2 D. Zn(OH) 2 9. When 250 ml of 0.36 M Sr(OH) 2 are added to 750 ml of water, the resulting ion concentrations are A. [Sr 2+ ] = 0.12 M and [OH - ] = 0.12 M B. [Sr 2+ ] = 0.12 M and [OH - ] = 0.24 M C. [Sr 2+ ] = M and [OH - ] = M D. [Sr 2+ ] = M and [OH - ] = M 10. When equal volumes of 2.0 M Pb(NO 3 ) 2 and 2.0 M KCl are mixed, A. a precipitate forms because the trial ion product < K sp B. a precipitate forms because the trial ion product > K sp C. a precipitate does not form because the trial ion product < K sp D. a precipitate does not form because the trial ion product > K sp 11. Consider the following equilibrium: AgCl(s) Ag+ + Cl- When Br - is added to a saturated solution of AgCl, A. more AgCl dissolves and its solubility product increases. B. more AgCl precipitates and its solubility product decreases. C. more AgCl dissolves and its solubility product remains constant. D. more AgCl precipitates and its solubility product remains constant. 12. The molar solubility of iron II sulphide is A. 3.6 x M 9

10 B. 3.0 x M C. 6.0 x M D. 7.7 x M 13. A solution containing an unknown cation was added to three solutions and the following observations were recorded: Solution NaI Na 2 SO 4 NaOH Observation no precipitate precipitate no precipitate The unknown cation is A. Pb 2+ B. Sr 2+ C. Ca 2+ D. Ag If the solubility of Pb(OH) 2 is g/l, then the concentration of each ion in a saturated solution is A. [Pb 2+ ] = g/l and [OH - ] = g/l B. [Pb 2+ ] = g/l and [OH - ] = g/l C. [Pb 2+ ] = 6.43 x 10-4 M and [OH - ] = 1.29 x 10-3 M D. [Pb 2+ ] = 6.43 x 10-4 M and [OH - ] = 6.43 x 10-3 M 15. Which of the following could be used to separate Pb 2+ from Ba 2+ by precipitation? A. Na 2 S B. NaOH C. Na 2 CO 3 D. Na 2 SO When dissolved in water, which of the following form a molecular solution? A. HCl (g) B. NaNO 3(s) C. CH 3 OH (l) D. K 2 SO 4(s) 17. Which of the following will be most soluble in water at 25 o C. A. AgI B. PbS C. MgSO 4 D. Ba(OH) At 25 oc, the solubility of Mg(OH) 2 is A. 1. x M B. 1. x M C. 1. x 10-6 M D. 1. x 10-4 M 10

11 19. At 25 oc, the solubility of an unknown compound is 7.1 x 10-5 M. The compound is A. CuI B. AgI C. CaCO 3 D. CaSO When solid AgBr is added to a saturated solution of AgBr, the reaction rates can be described as: Rate of Dissolving Rate of Crystalizing A. increasing increasing B. increasing decreasing C. decreasing increasing D. increasing no change 21. The solubility of PbS is 2.9 x M. What is the value of the Ksp. A. 8.4 x B. 2.9 x C. 5.8 x D. 1.7 x Which of the following causes a precipitate to form when Sr 2+ is added but not when Zn 2+ is added? A. S B. Cl - C. SO 4 D. CO A 3.0 L solution of NiCl 2 is found to have a chloride concentration of 0.60 M. The concentration of nickel II ions is A M B M C M D. 1.2 M 24. When equal volumes of 0.20 M K 2 CO 3 and 0.2 M Na 3 PO 4 are mixed, A. no precipitate will form B. a precipitate of K 3 PO 4 will form C. a precipitate of Na 2 CO 3 will form D. a precipitate of K 3 PO 4 and Na 2 CO 3 will form 25. A solution of AgNO 3 is slowly added to a mixture containing 0.10 M I -, Cl -, Br -, and IO 3 -. The precipitate which forms first is A. AgI B. AgCl 11

12 C. AgBr D. AgIO Which of the following units can be used to represent solubility? A. g B. mol C. mol/l D. ml/s 27. Consider the following equilibrium: CaCO 3(s) Ca 2+ + CO 3 Which of the following reagents when added to the equilibrium system, would cause more CaCO 3 to dissolve? A. KNO 3(s) B. CaCO 3(s) C. H 2 C 2 O 4(s) D. Na 2 CO 3(s) 28. Which of the following could be used to precipitate both Mg 2+ and Ca 2+ from hard water? A. lithium sulphate B. sodium phosphate C. potassium sulphide D. ammonium chloride 29. What is the maximum [Ag + ] that can exist in 0.20 M NaBrO 3? A. 1.1 x 10-5 M B. 5.3 x 10-5 M C. 2.6 x 10-4 M D. 7.3 x 10-3 M 30. Which of the following ions could be used to separate Cl - from SO 4 by precipitation? A. Ag + B. Ca 2+ C. + NH 4 D. Pb The Ksp expression for a saturated solution Ca 3 (PO 4 ) 2 is A. K sp = [Ca 2+ ][PO 3-4 ] B. K sp = [Ca 2+ ] 3 [PO 3-4 ] 2 C. K sp = [3Ca 2+ ][2PO 3-4 ] D. K sp = [3Ca 2+ ][2PO 3-4 ] 32. When Ca(OH) 2 attains solubility equilibrium, the A. solution will be saturated 12

13 B. ph will be less than 7 C. trial K sp is less than the K sp D. concentrations of the ions are equal 33. Which of the following describes the changes in ion concentrations when 1.0 g of solid ZnS is added to a saturated solution of ZnS? [Zn 2+ ] [S ] A. increases decreases B. decreases decreases C. increases increases D. remains constant remains constant 34. The net ionic equation for the reaction between Sr(OH) 2 and H 2 SO 4 is A. H + + OH - H 2 O B. Sr 2+ + SO 4 SrSO 4 C. Sr(OH) 2 + H 2 SO 4 SrSO 4 + 2H 2 O D. Sr OH - + 2H + + SO 4 SrSO 4 + 2H 2 O 35. The relationship between the solubility and the size of the K sp is A. there is no relationship B. the smaller the K sp the greater the solubility C. the greater the K sp the greater the solubility D. the solubility is always the square root of the K sp 13

14 36. Which of the following compounds will form a saturated solution with the greatest concentration of Ag +? A. AgI B. AgBr C. AgIO 3 D. AgBrO When equal volumes of 0.20 M CuSO 4 and 0.20 M Li 2 S are combined, the complete ionic equation is A. Cu 2+ + S CuS (s) B. CuSO 4 + Li 2 S CuS (s) + Li 2 SO 4 C. Cu 2+ + SO 4 + 2Li + + S CuS (s) + Li 2 SO 4 D. Cu 2+ + SO 4 + 2Li + + S CuS (s) + 2Li + + SO Which of the following would have the [Fe 3+ ] = M? A L of M Fe(NO 3 ) 3 B L of M Fe 2 (SO 4 ) 3 C L of M FeC 6 H 5 O 7 D L of M Fe 2 (C 2 O 4 ) A solution contains both Ag + and Mg 2+ ions. During selective precipitation, these ions are removed one at a time by adding A. I - followed by OH - B. OH - followed by S C. SO 4 followed by Cl - D. NO followed by PO The solubility of an AB 2 type salt is 2.3 x 10-6 M. The salt is A. PbBr 2 B. Fe(OH) 2 C. Cu(IO 3 ) 2 D. Mg(OH) 2 1. A saturated solution of BaSO 4 is given to patients needing digestive tract x-rays. a) Write an equation that represents the solubility equilibrium BaSO 4(s) Ba 2+ + SO 4 14

15 b) Calculate the [Ba 2+ ] present in the saturated solution. x 2 = 1.1 x [Ba 2+ ] = x = 1.0 x 10-5 M 2. Will a precipitate form when 90.0 ml of 1.00 x 10-2 M Cu(NO 3 ) 2 and 10.0 ml of 1.00 x 10-2 M NaIO 3 are mixed? Explain using appropriate calculations. Cu(IO 3 ) 2(s) Cu IO 3-90 x.0100m 10 x.0100m M M Trial ion product = ( )( ) 2 = 9.0 x 10-9 < 6.9 x 10-8 (Ksp) therefore there is no precipitate. 3. What is the maximum [CO 3 ] that can exist in a 1.3 x 10-4 M AgNO 3 solution? Ag 2 CO 3(s) 2Ag + + CO x 10-4 M Ksp = [Ag + ] 2 [CO 3 ] 8.5 x = (1.3 x 10-4 ) 2 [CO 3 ] [CO 3 ] = 5.0 x 10-4 M 4. The following data was collected when a ml sample of water containing chloride ion was titrated using 0.100M AgNO 3 to completely precipitate the chloride ion. Initial volume of AgNO 3 Final volume of AgNO ml ml a) Write the net ionic reaction for the precipitation reaction. 15

16 Ag + + Cl - AgCl (s) c) Calculate the [Cl - ] L Ag + x mole x 1 mole Cl- [Cl - ] = L 1 mole Ag + = 3.57 x 10-2 M.0250 L 5. In an experiment to determine the solubility of BaF 2, ml of the saturated solution was heated in an evaporating dish to remove the water. The evaporating dish and the residue were then heated two more times to ensure all the water was removed. Volume of the saturated solution of BaF 2 Mass of the evaporating dish Mass of the evaporating dish and BaF 2 after the first heating Mass of the evaporating dish and BaF 2 after the second heating Mass of the evaporating dish and BaF 2 after the third heating ml g g g g Using the above data, calculate the Ksp for BaF 2 Mass of BaF 2 = = 0.315g Molarity = 0.315g x 1 mole 175.3g = M.500L Ksp = [ ][ ] 2 = 1.86 x