Modified True/False

ch7&8 review

Modified True/False

Indicate whether the sentence or statement is true or false. If false, change the identified word or phrase to make the sentence or statement true.

____ 1. A precipitate forms when the ion product for the precipitate exceeds the Ksp. ______

____ 2. When a solution of silver nitrate is mixed with a solution of potassium iodide a precipitate of lead iodide never forms when [I1-][Ag1+] exceeds the Ksp. ______

____ 3. A solution of lead(II) nitrate is mixed with a solution of sodium iodide and a precipitate forms. The precipitate is lead(II) iodide. ______

____ 4. When a precipitate forms at the bottom of a container after 2 unsaturated solutions are mixed, the solid precipitate is always in equilibrium with its liberated ions in solution. ______

____ 5. Ksp values are temperature dependent. ______

____ 6. More potassium bromide can dissolve in distilled water than in a solution of potassium chloride. ______

____ 7. The formula for silver acetate is AgC3H5O2. ______

____ 8. The Ksp equilibrium expression for lead(II) chloride is Pb2Cl(s) <====> 2Pb2+(aq) + Cl1-(aq). ______

____ 9. When 25 mL of 0.24 mol/L CaCl2 is mixed with 45 mL of 1.5 mol/L AgNO3 a precipitate of AgCl forms since the Ksp of AgCl is 1.8 ´ 10-10. ______

____ 10. The Ksp's of CuCl and TlCl are 1.9´10-7 and 1.8 ´ 10-4 respectively. This means TlCl is more soluble than CuCl. ______

____ 11. The pH of 0.0050 mol/L solutions of Ca(OH)2 and NaOH are compared. The NaOH has a higher pH. ______

____ 12. The Ksp expression for magnesium phosphate is

Mg3(PO4)2(s) <====> 3 Mg2+(aq) + 2 PO43-(aq). ______

____ 13. For the gaseous equilibrium shown, 3A + B <====> C + 2D, some C is added to the system. The quantity of D will rise. ______

____ 14. For the gaseous equilibrium shown, 2A + 3B <====> C + 2D + heat.

If the temperature of the system is decreased, the quantity of B will increase 3/2 as much as the quantity of A. ______

____ 15. For the gaseous equilibrium shown, 3A + B <====> 4C + D + heat.

If some B is removed from the system, the quantity of C will decrease 4´'s as much as the quantity of D decreases. ______

____ 16. For the gaseous equilibrium shown, 2A + 3B <====> 4C + D + heat.

If some B is added to the system, the quantity of C will decrease 4´'s as much as the quantity of D decreases. ______

____ 17. In a saturated solution of silver carbonate, the quantity of silver ion = the quantity of carbonate ion. ______

____ 18. In a saturated solution of cobalt(II) hydroxide, the quantity of cobalt(II) ion is double the quantity of hydroxide ion. ______

____ 19. A system at equilibrium means the concentration of reactants is equal to the concentration of products. ______

____ 20. In a saturated solution of aluminum hydroxide the [Al3+] is always 1/3 the [OH1–]. ______

____ 21. The pH scale ranges from 0 to 14. ______

____ 22. A concentrated weak acid cannot have a lower pH than a dilute strong acid. ______

____ 23. A concentrated weak base can have a lower pOH than a dilute strong base. ______

____ 24. 1.0 mol/L solutions of weak bases will have a higher pH than 1.0 mol/L solutions of strong bases. ______

____ 25. Conjugate acid base partners differ by a single proton. ______

____ 26. Salts containing an anion which is found in a strong acid cannot act like weak bases. ______

____ 27. Salts containing anion which is not found in a strong acid can act like weak bases. ______

____ 28. Salts contain cations found in the alkali metal family cannot act like weak acids. ______

____ 29. Sodium ions have too weak a pull on water's electrons to make donating protons impossible. ______

____ 30. If the pH of an aquatic solution at 95oC is 4.5 the pOH must be 9.5. ______

____ 31. The Kb expression for SO42- ion is Kb = [HSO42-][OH1-] / [SO42-]. ______

____ 32. The Ka expression for H2PO41- is Ka = [OH1-][H3PO4] / [H2PO41-] ______

____ 33. The Kb expression for H2PO41- is Kb = [OH1-][H3PO4] / [H2PO41-]. ______

____ 34. During acid - base titrations the products are always neutral salts and water. ______

____ 35. When HCl is titrated with NaOH the endpoint is indicated when an excess of HCl turns the indicator a different colour. ______

Completion

Complete each sentence or statement.

36. If solutions of barium chloride and sodium sulfate were mixed and a precipitate formed, the precipitate would be ______.

37. If solutions of silver nitrate and copper(II) bromide were mixed and a precipitate formed, the precipitate would be ______.

38. If solutions of strontium chloride and potassium chromate were mixed and a precipitate formed, the precipitate would be ______.

39. If solutions of lead(II) nitrate and lithium chloride were mixed and a precipitate formed, the precipitate would be ______.

40. If solutions of aluminum fluoride and potassium hydroxide were mixed and a precipitate formed, the precipitate would be ______.

41. If solutions of sodium oxalate and magnesium chloride were mixed and a precipitate formed, the precipitate would be ______.

42. If solutions of calcium fluoride and potassium carbonate were mixed and a precipitate formed, the precipitate would be ______.

43. If solutions of sodium phosphate and zinc bromide were mixed and a precipitate formed, the precipitate would be ______.

44. If solutions of silver nitrate and potassium cyanide were mixed and a precipitate formed, the precipitate would be ______.

45. If solutions of lithium sulfite and barium iodide were mixed and a precipitate formed, the precipitate would be ______.

46. If solutions of barium chloride and sodium sulfate were mixed and a precipitate formed, the equilibrium equation for the precipitate would be ______.

47. If solutions of copper(II) nitrate and sodium carbonate were mixed and a precipitate formed, the equilibrium equation for the precipitate would be ______.

48. If solutions of iron(II) chloride and potassium phosphate were mixed and a precipitate formed, the equilibrium equation for the precipitate would be ______.

49. If solutions of potassium chromate and silver nitrate were mixed and a precipitate formed, the equilibrium equation for the precipitate would be ______.

50. If solutions of calcium nitrate and sodium fluoride were mixed and a precipitate formed, the equilibrium equation for the precipitate would be ______.

51. When solid magnesium carbonate is in equilibrium with its ions, the ratio of magnesium ion to carbonate ion is ______.

52. When solid lead(II) phosphate is in equilibrium with its ions, the ratio of lead(II) ion to phosphate ion is ______.

53. When solid barium monohydrogen phosphate is in equilibrium with its ions, the ratio of barium ion to monohydrogen phosphate ion is ______.

54. When solid zinc hydroxide is in equilibrium with its ions, the ratio of zinc ion to hydroxide ion is ______.

55. When solid mercury(II) iodide is in equilibrium with its ions, the ratio of mercury(II) ion to iodide ion is ______.

56. CO(g) + 2H2(g) ® CH3OH(l); during this reaction the entropy ______.

57. S(s) + 2N2O(g) ® SO2(g) + 2N2(g); during this reaction the entropy ______.

58. NH3(g) + HCl(g) ® NH4Cl(s); during this chemical change the algebraic sign for the entropy change is predicted to be ______.

59. 4NO(g) ® 2N2O(g) + O2(g); during this chemical change the algebraic sign for the entropy change is predicted to be ______.

60. A system at equilibrium always has forward and reverse reactions which are ______.

61. A buffer solution can contain a weak acid and a ______.

62. A buffer can contain a weak base and a salt containing ______.

63. A 1.5 mol/L solution of HCl(aq) has a pH of ______.

64. The pH of a 0.25 mol/L solution of HCl at 25oC is ______.

65. A solution at 25oC with a pOH of 3.45 has a pH of ______.

66. The [H1+] of a 0.95 mol/L solution of HBr at 25oC is ______.

67. Baking soda, NaHCO3, acts like a base because ______.

68. The pH of an acidic solution is always ______.

69. The pOH of a basic solution is always ______.

70. The pOH of an acidic solution is always ______.

71. When potassium hydroxide is titrated to an end point by sulfuric acid the salt formed is ______.

72. When nitric acid is titrated to an end point by lithium hydroxide the salt formed is ______.

73. When iron(III) hydroxide is combined with carbonic acid the salt formed is ______.

74. Bronsted and Lowry's definition of acids is acids are substances which ______.

Essay

75. Given this equilibrium

2A(g) + 3B(g) <=====> C(g) + 4D(g) + energy

Discuss what happens to this equilibrium if the temperature increases while the pressure is held constant. Make sure to include a discussion of the rates of the forward and reverse reactions as well as changes in the concentrations of A, B, C and D.

76. Shown below is the Haber process for the commercial production of ammonia.

N2(g) + 3H2(g) <=====> 2NH3(g) + 92 kJ

Discuss how Haber maximized the production of ammonia by manipulating this equilibrium. Also point out the importance of this industrial process to a growing world population. Make sure to establish a link between ammonia and protein.

77. Acid rain is a serious environmental problem. Given the equations for a variety of chemical reactions which contribute to this problem, discuss how human activity adds to the overall load of acidic substances. Make sure to include in your discussion strong and weak acids and include equilibrium expressions for one weak acid. Also discuss how the oxides of sulfur and nitrogen are formed through combustion and describe how these oxides react with water forming strong and weak acids. Suggest some measures which would reduce the problem.

N2(g) + O2(g) <====>2NO(g)

2NO(g) + O2(g) ------> 2NO2(g)

SO2(g) + H2O(g) ------> H2SO3(aq)

2NO2(g) + H2O(g)----->HNO3(aq) + HNO2(aq)

SO3(g) + H2O ------> H2SO4(aq)

S(s) + O2(g) ------> SO2(g)

2SO2(g) + O2(g) ------> 2SO3(g)

78. Impurities of sulfur in coal, natural gas and gasoline create environmental problems. Limestone is an abundant natural resource which contains CaCO3. Use these equations to discuss how the rain is becoming increasing acidified and suggest potential solutions to our acid rain problems.

N2(g) + O2(g) <====>2NO(g)

2NO(g) + O2(g) ------> 2NO2(g)

SO2(g) + H2O(g) ------> H2SO3(aq)

2NO2(g) + H2O(g)----->HNO3(aq) + HNO2(aq)

SO3(g) + H2O ------> H2SO4(aq)

S(s) + O2(g) ------> SO2(g)

2SO2(g) + O2(g) ------> 2SO3(g)

CaCO3(s) + SO2(g) -----> CaSO3(g) + CO2(g)

ch7&8 review

Answer Section

MODIFIED TRUE/FALSE

1. ANS: T REF: I OBJ: 7.6

LOC: CS2.05

2. ANS: F, only forms REF: I OBJ: 7.6

LOC: CS2.05

3. ANS: T REF: K/U OBJ: 7.6

LOC: CS2.05

4. ANS: T REF: K/U OBJ: 7.1

LOC: CS2.01

5. ANS: T REF: K/U OBJ: 7.6

LOC: CS2.01

6. ANS: T REF: I OBJ: 7.6

LOC: CS2.05

7. ANS: F, AgC2H3O2 REF: K/U OBJ: 7.1

LOC: CS1.10

8. ANS: F

PbCl2(s) <====> Pb2+(aq) + 2Cl1-(aq)

REF: K/U OBJ: 7.6 LOC: CS2.06

9. ANS: T REF: I OBJ: 7.6

LOC: CS2.05

10. ANS: T REF: K/U OBJ: 7.1

LOC: CS1.01

11. ANS: F, Ca(OH)2 has a higher pH REF: I OBJ: 7.3

LOC: CS2.06

12. ANS: T REF: K/U OBJ: 7.6

LOC: CS1.01

13. ANS: F, [D] will decrease REF: I OBJ: 7.3

LOC: CS1.03

14. ANS: F, decrease 3/2 as much REF: I OBJ: 7.3

LOC: CS1.03

15. ANS: T REF: I OBJ: 7.3

LOC: CS1.03

16. ANS: F, will increase 4´'s as much REF: I OBJ: 7.3

LOC: CS1.03

17. ANS: F, the quantity of silver ion is double the quantity of carbonate ion

REF: K/U OBJ: 7.6 LOC: CS1.06

18. ANS: F, the quantity of hydroxide ion is double the quantity of cobalt(II) ion

REF: K/U OBJ: 7.6 LOC: CS1.06

19. ANS: F, forward reaction is equal to the rate of the reverse reaction

REF: K/U OBJ: 7.1 LOC: CS1.02

20. ANS: T REF: K/U OBJ: 7.1

LOC: CS1.02

21. ANS: F, from below 0 and above 14 REF: K/U OBJ: 8.1

LOC: CS2.01

22. ANS: F, can have REF: K/U OBJ: 8.1

LOC: CS1.02

23. ANS: T REF: I OBJ: 8.2

LOC: CS1.07

24. ANS: F, lower pH REF: I OBJ: 8.2

LOC: CS1.08

25. ANS: T REF: K/U OBJ: 8.1

LOC: CS2.06

26. ANS: T REF: MC OBJ: 8.3

LOC: CS2.07

27. ANS: T REF: MC OBJ: 8.3

LOC: CS2.07

28. ANS: T REF: K/U OBJ: 8.3

LOC: CS2.07

29. ANS: T REF: K/U OBJ: 8.3

LOC: CS2.07

30. ANS: F, pH + pOH = 14 only at 25oC REF: I OBJ: 8.1

LOC: CS2.06

31. ANS: F

Kb = [HSO41-][OH1-] / [SO42-]

REF: I OBJ: 8.3 LOC: CS2.07

32. ANS: F, Kb expression REF: I OBJ: 8.2

LOC: CS1.07

33. ANS: T REF: K/U OBJ: 8.3

LOC: CS2.08

34. ANS: F, are not always REF: K/U OBJ: 8.4

LOC: CS2.08

35. ANS: F, NaOH REF: K/U OBJ: 8.4

LOC: CS2.08

COMPLETION

36. ANS: barium sulfate REF: K/U OBJ: 7.6

LOC: CS1.06

37. ANS: silver bromide REF: K/U OBJ: 7.6

LOC: CS1.06

38. ANS: strontium chromate REF: K/U OBJ: 7.6

LOC: CS1.06

39. ANS: lead(II) chloride REF: K/U OBJ: 7.6

LOC: CS1.06

40. ANS: aluminium hydroxide REF: K/U OBJ: 7.6

LOC: CS1.06

41. ANS: magnesium oxalate REF: K/U OBJ: 7.6