Redox and Electrochemistry – Ch17 | Test Bank – 15th

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Package Title: Hein Test Bank

Course Title: Hein 15e

Chapter Number: 17

Question Type: Multiple Choice

1. What is the oxidation number of chlorine in HClO₄?

A. 0

B. +7

C. –1

D. –3

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

2. What is the oxidation number of manganese in MnO₂?

A. +2

B. -4

C. +4

D. 0

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

3. The oxidation number of Sulfur in S₈, S₂F₂ and H₂S are

A. 0, +1 and -2

B. +2, +1 and -2

C. 0, +1 and +2

D. –2, +1 and -2

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

4. What is the oxidation number of bromine in Br₂?

A. 0

B. –1

C. +7

D. –5

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

5. What is the oxidation number of chromium in Cr₂O₇^2–?

A. +12

B. 0

C. +6

D. –4

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

6. What is the oxidation number of Mn in KMnO₄?

A. +7

B. -7

C. +1

D. –1

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

7. What is the oxidation number of oxygen in H₂O₂?

A. –2

B. 0

C. +2

D. –1

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Section Reference: Section 17.1

8. What is the oxidation number of S in S₂O₃^2-?

A. -2

B. +2

C. +6

D. 0

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

9. What is the oxidation number of carbon in HCO₃^– in?

A. +5

B. +4

C. –1

D. –2

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Section Reference: Section 17.1

10. Oxygen has an oxidation state of +2 in

A. H₂O₂

B. H₂O

C. OF₂

D. SO₂

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

11. Oxidation involves the

A. gain of protons.

B. loss of protons.

C. gain of electrons.

D. loss of electrons.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

12. Reduction involves the

A. gain of protons.

B. loss of protons.

C. gain of electrons.

D. loss of electrons.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Section Reference: Section 17.1

13. What is the oxidation number of phosphorous in P₄?

A. –4

B. –1

C. +4

D. 0

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Section Reference: Section 17.1

14. During a redox reaction, the oxidation number of the species oxidized will

A. increase.

B. decrease.

C. remains the same.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

15. What always occurs at the cathode in an electrolytic cell?

A. Protons are gained

B. Protons are lost

C. Electrons are gained

D. Electrons are lost

Difficulty: easy

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

16. What always occurs at the anode in an electrolytic cell?

A. Protons are gained.

B. Protons are lost.

C. Electrons are gained.

D. Electrons are lost.

Difficulty: medium

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

17. The reducing agent is

A. the species that is reduced.

B. the species with a negative charge.

C. the species that loses electrons.

D. the species that gains electrons.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

18. The oxidizing agent is

A. the species that is oxidized.

B. the species with a positive charge.

C. the species that loses electrons.

D. the species that gains electrons.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

19. What always travels through the salt bridge in a voltaic cell?

A. protons

B. electrons

C. neutrons

D. ions

Difficulty: easy

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

20. In a voltaic (or Galvanic) cell, the anode is assigned as the

A. positive electrode.

B. negative electrode

C. neutral electrode

Difficulty: easy

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

21. In an electrolytic cell

A. a chemical reaction occurs spontaneously and releases energy as electricity.

B. electricity causes a chemical reaction to occur.

C. a physical change occurs spontaneously and releases energy as electricity.

D. electricity causes a physical change to occur.

Difficulty: easy

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

22. In a voltaic cell

A. a chemical reaction occurs spontaneously and releases energy as electricity.

B. electricity causes a chemical reaction to occur.

C. a physical change occurs spontaneously and releases energy as electricity.

D. electricity causes a physical change to occur.

Difficulty: easy

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

23. Which species is oxidized in the following equation?

2 Na (s) + Cl₂ (g) → 2 NaCl (l)

A. Na

B. Cl₂

C. Na⁺

D. Cl^–

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

24. The conversion of sugar C₁₂H₂₂O₁₁ to CO₂ is

A. oxidation

B. reduction

C. none

D. both

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

25. Which species is reduced in the following equation?

2 Ca (s) + O₂ (g) → 2 CaO (s)

A. Ca

B. O₂

C. Ca²⁺

D. O^2–

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

26. Which species is reduced in the following equation?

2 H₂O (l) → 2 H₂ (g) + O₂ (g)

A. H₂

B. O₂

C. H⁺

D. O^2–

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

27. Balance this equation using ion-electron strategy in acid solution.

I^– (aq) + NO₃^– (aq) 🡪 NO (g) + I₂ (s)

What is the coefficient of the iodide ion in the balanced equation?

1. 1
2. 3
3. 5
4. 6

Difficulty: easy

Learning Objective 1: Balance equations for ionic oxidation–reduction reactions.

Reference: Section 17.3

28. Which species is the oxidizing agent in the following equation?

MnO₄^– (aq) + 8 H⁺ (aq) + 5e^– 🡪 Mn²⁺ (aq) + 4 H₂O (l)

A. Mn²⁺

B. H₂O

C. MnO₄^–

D. none of the above

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

29. Which species is the reducing agent in the following equation?

2 Ca + O₂→ 2 CaO

A. Ca

B. O₂

C. Ca²⁺

D. O^2–

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

30. Which species gets oxidized when zinc reacts with iodine to form zinc iodide?

A. zinc ions

B. iodide ions

C. zinc atom

D. iodine

Answer C

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

31. Which species is the oxidizing agent in the following equation?

2 H₂O → 2 H₂ + O₂

A. H⁺

B. O^2–

C. H₂

D. O₂

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

32. Which species is the reducing agent in the following equation?

2 Al₂O₃→ 4 Al + 3O₂

A. Al³⁺

B. O^2–

C. Al

D. O₂

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

33. Which species is the oxidizing agent in the following equation?

C + H₂O→ CO + H₂

A. C

B. H₂O

C. CO

D. H₂

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

34. Which is the correct oxidation half-reaction for the following equation?

2 Na + 2 H₂O → 2 NaOH + H₂

A. Na⁺ + e^– → Na

B. Na → Na⁺ + e^–

C. 2 H⁺ + 2 e^– → H₂

D. H₂ → 2 H⁺ + 2 e^–

Difficulty: easy

Learning Objective 1: Balance equations for oxidation–reduction reactions.

Reference: Section 17.2

35. Which of the following is the correct reduction half-reaction for the equation given below?

Zn + 2 Ag⁺ → Zn²⁺ + 2 Ag

A. Ag → Ag⁺ + 1 e^–

B. Ag⁺ + 1 e^– → Ag

C. Zn²⁺ + 2 e^– → Zn

D. Zn → Zn²⁺ + 2 e^–

Difficulty: easy

Learning Objective 1: Balance equations for oxidation–reduction reactions.

Reference: Section 17.2

36. Balance the following redox reaction using ion-electron method in acidic solution.

HNO₂ + I^– → I₂ + NO

What is the coefficient of H⁺ in the balanced equation?

1. 4
2. 3
3. 2
4. 1

Difficulty: easy

Learning Objective 1: Balance equations for ionic oxidation–reduction reactions.

Reference: Section 17.3

37. Which of the following is the correct reduction half-reaction for the equation given below?

Zn + 2 HCl → ZnCl₂ + H₂

A. Zn → Zn²⁺ + 2 e^–

B. Zn²⁺ + 2 e^– → Zn

C. 2 H⁺ + 2 e^– → H₂

D. H₂ → 2 H⁺ + 2 e^–

Difficulty: easy

Learning Objective 1: Balance equations for oxidation–reduction reactions.

Reference: Section 17.2

38. Which of the following occurs when a calcium atom is oxidized?

A. Two protons are lost.

B. Two protons are gained.

C. Two electrons are lost.

D. Two electrons are gained.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

39. Which of the following occurs when a sodium atom is oxidized?

A. One electron is gained.

B. One electron is lost.

C. One proton is gained.

D. One proton is lost.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

40. Which of the following occurs when an oxygen atom is reduced?

A. Two protons are lost.

B. Two protons are gained.

C. Two electrons are lost.

D. Two electrons are gained.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

41. Which of the following occurs when a fluorine atom is reduced?

A. One proton is lost.

B. One proton is gained.

C. One electron is lost.

D. One electron is gained.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

42. How many moles of electrons are needed to reduce 1 mol MnO₄^– to 1 mol Mn²⁺?

A. 1 mol

B. 3 mol

C. 4 mol

D. 5 mol

Difficulty: medium

Learning Objective 1: Balance equations for ionic oxidation–reduction reactions.

Reference: Section 17.3

43. For the reaction Ba + CuO → BaO + Cu

How many moles of electrons are required to convert 1 mol Ba to 1mol BaO?

1. 4 mol
2. 3 mol
3. 2 mol
4. 1 mol

Difficulty: easy

Learning Objective 1: Balance equations for ionic oxidation–reduction reactions.

Reference: Section 17.3

44. In a redox reaction, the total number of electrons gained is

A. greater than the total number of electrons lost.

B. less than the total number of electrons lost.

C. equal to the number of electrons lost.

D. not related at all to the number of electrons lost.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

45. How many moles of electron are lost when one mole of barium atoms is oxidized to one

mole of barium ions?

A. 2 mol

B. 1 mol

C. 4 mol

D. 3 mol

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

46. How many moles of electrons are lost when three moles of aluminum atoms are oxidized to aluminum ions?

A. 2 mol

B. 3 mol

C. 6 mol

D. 9 mol

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

47. How many moles of electrons are gained when three moles of oxygen atoms are reduced to oxide ions?

A. 2 mol

B. 3 mol

C. 4 mol

D. 6 mol

Difficulty: easy

Learning Objective: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

48. How many moles of electrons are gained when two moles of fluorine atoms are reduced to fluoride ions?

A. 1 mol

B. 2 mol

C. 4 mol

D. 8 mol

Difficulty: easy

Learning Objective: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

49. A redox reaction is a reaction in which

A. only oxidation occurs.

B. only reduction occurs.

C. both reduction and oxidation occur.

D. neither oxidation nor reduction occur.

Difficulty: easy

Learning Objective: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

50. In the following redox reaction

F₂(g) + 2NaI(aq) I₂(s) + 2NaF(aq)

the total number of moles of electrons transferred between one mole of the oxidizing agent and reducing agent is

A. 1 mol.

B. 3 mol.

C. 0.5 mol.

D. 2 mol.

Difficulty: easy

Learning Objective 1: Balance equations for oxidation–reduction reactions.

Reference: Section 17.2

51. In the following redox reaction

2Fe₂O₃ + 3C 6Fe + 3CO₂

the total number of moles of electrons transferred between the oxidizing agent and reducing agent is

A. 12 mol.

B. 4 mol.

C. 3 mol.

D. 6 mol.

Difficulty: easy

Learning Objective 1: Balance equations for oxidation–reduction reactions.

Reference: Section 17.2

52. In the following redox reaction

2Mn⁷⁺ + 5C₂O₄^2- 2Mn²⁺ + 10CO₂

the total number of moles of electrons transferred between oxidizing agent and reducing agent is

A. 2 mol.

B. 5 mol.

C. 6 mol.

D. 10 mol.

Difficulty: medium

Learning Objective 1: Balance equations for oxidation–reduction reactions.

Reference: Section 17.2

53. Based on the activity series, which of the following is the most easily oxidized?

A. Al

B. Cr

C. Pb

D. Ag

Difficulty: easy

Learning Objective 1: Use the activity series of metals to predict whether a reaction will occur.

Reference: Section 17.4

54. Based on the activity series, which of the following is the most easily reduced?

A. Al³⁺

B. Cr³⁺

C. Pb²⁺

D. Ag⁺

Difficulty: medium

Learning Objective 1: Use the activity series of metals to predict whether a reaction will occur.

Reference: Section 17.4

55. Based on the activity series, which of the following is the strongest reducing agent?

A. Cr

B. Fe²⁺

C. Zn

D. H₂

Difficulty: medium

Learning Objective 1: Use the activity series of metals to predict whether a reaction will occur.

Reference: Section 17.4

56. Based on the activity series, which of the following is the strongest reducing agent?

A. Al

B. Cr

C. Pb

D. Ag

Difficulty: medium

Learning Objective 1: Use the activity series of metals to predict whether a reaction will occur.

Reference: Section 17.4

57. Based on the activity series, which of the following is the weakest reducing agent?

A. Al

B. Cr

C. Pb

D. Ag

Difficulty: medium

Learning Objective 1: Use the activity series of metals to predict whether a reaction will occur.

Reference: Section 17.4

58. Which of the following is conserved in all oxidation-reduction reactions?

A. mass, only

B. charge, only

C. Both mass and charge

D. Neither mass nor charge

Difficulty: easy

Learning Objective 1: Balance equations for oxidation–reduction reactions.

Reference: Section 17.2

59. In the following reaction, the chlorine atoms

2 Na + Cl₂ → 2 NaCl

A. gain electrons.

B. lose electrons.

C. gain protons.

D. lose protons.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

60. In the following reaction, the hydrogen atoms

2 H₂ + O₂ → 2 H₂O

A. gain protons.

B. lose protons.

C. gain electrons.

D. lose electrons.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

61. For the following reaction occurring in a voltaic cell

Zn + 2 Ag⁺ → Zn²⁺ + 2 Ag

Which of the following is produced at anode?

1. Zn
2. Ag⁺
3. Zn²⁺
4. Ag

Difficulty: medium

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

62. Consider following reaction occurring in a voltaic cell.

Ni + Cu²⁺ → Ni²⁺ + Cu

Which of the following is produced at the cathode?

1. Ni
2. Cu²⁺
3. Ni²⁺
4. Cu

Difficulty: medium

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

63. What is the oxidation number of chromium in MgCrO₄?

A. –2

B. 0

C. +2

D. +6

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

64. What is the oxidation number of hydrogen in NH₃?

A. –3

B. –1

C. +1

D. +3

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

65. What is the oxidation number of oxygen in F₂?

A. –2

B. –1

C. 0

D. +2

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

66. What is the oxidation number of sulfur in H₂SO₄?

A. +2

B. +4

C. +6

D. –2

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

67. Based on oxidation number, PbO₂ would be named as

A. lead oxide.

B. lead dioxide.

C. lead(II) oxide.

D. lead(IV) oxide.

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

68. Based on oxidation number, Cu₂O would be named as

A. dicopper oxide.

B. copper (I) oxide.

C. dicopper(I) oxide.

D. copper (II) oxide.

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

69. What is the oxidation number of iron in Fe₂O₃?

A. +2

B. +4

C. +3

D. +6

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

70. What is the oxidation number of hydrogen in MgH₂?

A. -2

B. +2

C. +1

D. –1

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

71. Consider the following reaction.

MnO₄^– + H₂SO₃ 🡪 SO₄ ^2– + Mn²⁺

Which of the following is the reducing agent?

1. MnO₄^–
2. H₂SO₃
3. Mn²⁺
4. SO₄ ^2–

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

72. When the following reaction is balanced in basic solution,

KOH + Cl₂ KCl + KClO

_____moles of water molecules will appear on the _________ side of the balanced

equation.

A. two, reactant

B. four, product

C. two, product

D. four, reactant

Difficulty: medium

Learning Objective 1: Balance equations for oxidation–reduction reactions.

Reference: Section 17.2

73. Balance the following reaction in acidic solution.

Cr₂O₇ ^2- (aq) + Fe ²⁺(aq) 🡪 Cr ³⁺ (aq) + Fe ³⁺ (aq)

What is the coefficient of water in the balanced reaction?

1. 7
2. 6
3. 5
4. 4

Difficulty: medium

Learning Objective 1: Balance equations for ionic oxidation–reduction reactions.

Reference: Section 17.3

74. When the following equation is balanced in acidic solution

+ S NO₂ +

one of the terms in the balanced equation will be:

A. 8 H⁺

B. 2 H₂O

C. 6 H₂O

D. 2 NO₂

Difficulty: medium

Learning Objective 1: Balance equations for ionic oxidation–reduction reactions.

Reference: Section 17.3

75. In acidic solution, the reaction MnO₄^- Mn²⁺ involves

A. oxidation by 3 electrons

B. reduction by 3 electrons

C. oxidation by 5 electrons

D. reduction by 5 electrons

Difficulty: medium

Learning Objective 1: Balance equations for ionic oxidation–reduction reactions.

Reference: Section 17.3

76. In an electrolytic cell the charge associated with the cathode is

A. positive.

B. negative.

C. neutral.

Difficulty: easy

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

77. In the electrolysis of fused (molten) calcium chloride, the product formed at the cathode is

A. Ca²⁺.

B. Cl^–.

C. Cl₂.

D. Ca.

Difficulty: easy

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

78. In the electrolysis of fused (molten) sodium chloride, the product formed at the cathode is

A. Na⁺.

B. Na

C. Cl^–.

D. Cl₂.

Difficulty: easy

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

79. In the electrolysis of fused (molten) sodium chloride, the product formed at the anode is

A. Na.

B. Na⁺.

C. Cl^–.

D. Cl₂.

Difficulty: easy

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

80. In the electrolysis of fused (molten) calcium chloride, the product formed at the anode is

A. Cl^–.

B. Cl₂.

C. Ca²⁺.

D. Ca.

Difficulty: easy

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

81. Which of the following is the principal characteristic of all redox reactions?

A. formation of water

B. formation of a gas or precipitate

C. irreversible reaction

D. transfer of electrons

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

82. Nitrogen has a +3 oxidation number in

A. N₂O.

B. N₂O₃.

C. N₂O₄.

D. NO.

Difficulty: easy

Learning Objective: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

83. Which of the following does not involve oxidation-reduction?

A. burning sodium in chlorine

B. formation of iron(II) sulfide from its elements

C. decomposition of potassium chlorate

D. neutralization of sodium hydroxide by sulfuric acid

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

84. In a voltaic cell, oxidation occurs

A. at the anode.

B. at the cathode.

C. in the salt bridge.

D. in the external circuit

Difficulty: easy

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

85. In a voltaic cell, reduction occurs

A. in the salt bridge

B. in the external circuit

C. at the cathode

D. at the anode

Difficulty: easy

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

86. All the following are true for a galvanic cell except which one?

A. Oxidation occurs at the cathode.

B. A spontaneous reaction takes place in the cell.

C. Cations are attracted to the cathode.

D. The salt bridge allows the migration of ions.

Difficulty: easy

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

87. In Ba(NO₃)₂, the oxidation number of nitrogen is

A. –3.

B. -1.

C. +4.

D. +5.

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

88. In Ca(HCO₃)₂, the oxidation number of carbon is

A. +2

B. –2

C. +4

D. +6

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

89. The products of the reaction between solid magnesium metal and water are

A. Mg(OH)₂(aq) and H₂(g).

B. MgO₂(aq) and H₂(g).

C. MgH₂(aq) + O₂(g).

D. No reaction takes place.

Difficulty: medium

Learning Objective 1: Use the activity series of metals to predict whether a reaction will occur.

Reference: Section 17.4

90. The products of the reaction between iron metal and calcium chloride are

A. FeCl₂(aq) + Ca(s).

B. No reaction takes place.

C. FeCl(aq) + CaCl(aq).

D. CaFe(s) + Cl₂(g).

Difficulty: medium

Section Reference 1: Use the activity series of metals to predict whether a reaction will occur.

Reference: Section 17.4

91. Moving from the top to the bottom of the activity series of the metals

A. arranges the metals by increasing number of electrons lost.

B. arranges the metals by decreasing ease of reduction.

C. arranges the metals by decreasing ease of oxidation.

D. arranges the metals by increasing reactivity.

Difficulty: medium

Learning Objective 1: Use the activity series of metals to predict whether a reaction will occur.

Reference: Section 17.4

92. Which of the following species will displace lead from Pb(NO₃)₂(aq):

A. Au

B. Hg

C. Cr³⁺

D. Ba

Difficulty: medium

Learning Objective 1: Use the activity series of metals to predict whether a reaction will occur.

Reference: Section 17.4

93. Which of the following species will displace nickel from Ni(C₂H₃O₂)₂(aq):

A. Cu(s)

B. Hg(l)

C. Ag(s)

D. Zn(s)

Difficulty: medium

Learning Objective 1: Use the activity series of metals to predict whether a reaction will occur.

Reference: Section 17.4

True/False

94. In oxidation, the oxidation number of an element increases in a positive direction as a result of gaining electrons.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

95. The change in oxidation number of an element from –2 to 0 is oxidation.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

96. The oxidation number of an element in its most stable form is zero.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

97. The oxidation number of an ion is the same as its charge.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

98. In an electrolytic cell, electrical energy is used to cause a chemical reaction to occur.

Difficulty: easy

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

99. The decomposition of calcium carbonate into calcium oxide and carbon dioxide is an example of an oxidation-reduction reaction.

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

100. In a voltaic cell, oxidation occurs at the anode.

Difficulty: easy

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

101. In the reaction, 2 F₂ + O₂ → 2 OF₂, oxygen is reduced.

Difficulty: medium

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

102. In a single-displacement reaction, the metal that is the best reducing agent displaces the ion of the metal that is a weaker reducing agent.

Difficulty: medium

Learning Objective 1: Use the activity series of metals to predict whether a reaction will occur.

Reference: Section 17.4

103. The algebraic sum of the oxidation numbers of the elements in a polyatomic ion is zero.

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

104. Oxygen has the same oxidation number in ozone (O₃) and in oxygen (O₂).

Difficulty: easy

Learning Objective 1: Assign oxidation numbers to the atoms in a compound.

Reference: Section 17.1

Free Response

105. Balance these equations using the change in oxidation-number method.

A. KMnO₄ + HCl → KCl + MnCl₂ + Cl₂ + H₂O

B. MnO₂ + HCl → MnCl₂ + H₂O + Cl₂

Difficulty: medium

Learning Objective 1: Balance equations for oxidation–reduction reactions.

Reference: Section 17.2

106. Balance these equations using the change-in oxidation-number method.

A. Cu + HNO₃ → Cu(NO₃)₂ + NO + H₂O

B. Na₂Cr₂O₇ + FeCl₂ + HCl → CrCl₃ + NaCl + FeCl₃ + H₂O

Difficulty: medium

Learning Objective 1: Balance equations for oxidation–reduction reactions.

Reference: Section 17.2

107. Balance the following equations which occur in acidic solution.

A. Cu + NO₃^– → Cu²⁺ + NO

B. NO₃^– + Cl^– → NO + Cl₂

2 NO + 3 Cl₂ + 4 H₂O

Difficulty: medium

Learning Objective 1: Balance equations for ionic oxidation–reduction reactions.

Reference: Section 17.3

108. Balance the following equations, which occur in acidic solution.

A. H₂O₂ + I^– → I₂

B. MnO₄^– + NO → Mn²⁺ + NO₃^–

5 NO₃^–

Difficulty: medium

Learning Objective 1: Balance equations for ionic oxidation–reduction reactions.

Reference: Section 17.3

109. Balance the following equations which occur in basic solution.

A. MnO₄^– + I^– → MnO₂ + IO₃^–

B. H₂O₂ + MnO₄ → O₂ + MnO₂

Difficulty: medium

Learning Objective 1: Balance equations for ionic oxidation–reduction reactions.

Reference: Section 17.3

110. Balance the following equation taking place in basic solution.

Cr(OH)₃ + IO₃^– → CrO₄^2- + I^–

Difficulty: medium

Learning Objective 1: Balance equations for ionic oxidation–reduction reactions.

Reference: Section 17.3

111. Balance the following equations which occur in basic solution.

A. S^2–+ I₂ → SO₄^2– + I^–

B. Cl₂ → Cl^– + ClO₃^–

Difficulty: medium

Learning Objective 1: Balance equations for ionic oxidation–reduction reactions.

Reference: Section 17.3

112. A voltaic cell is set up with one half-cell consisting of a strip of zinc metal in a 1.0 M zinc nitrate solution, and the other half-cell consisting of a strip of magnesium metal in a 1.0 M magnesium nitrate solution. Magnesium is more active than zinc.

A. Which species is oxidized? Write the oxidation half-reaction.

B. Which species is reduced? Write the reduction half-reaction.

C. Which electrode is the cathode?

D. Which electrode is the anode?

E. To which electrode will the electrons flow?

F. Toward which half-cell will anions migrate?

G. Toward which half-cell will cations migrate?

Difficulty: hard

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

113. An electrolytic cell is set up to carry out the electrolysis of fused (molten) sodium chloride.

A. Which species is oxidized? Write the oxidation half reaction.

B. Which species is reduced? Write the reduction half reaction.

C. Which ion is attracted to the cathode?

D. Which ion is attracted to the anode?

Difficulty: medium

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

114. Use the activity series at the right More active K

to predict whether each of the Ba

following reactions will occur Ca

spontaneously. Na

Mg

Al

Zn

Cr

Fe

A. Fe + Ca(NO₃)₂

B. Mg + Zn(NO₃)₂

C. K + Zn(NO₃)₂

D. Cr + NaNO₃

E. Mg + Ca(NO₃)₂

F. Ba + Al(NO₃)₃

Difficulty: easy

Learning Objective 1: Use the activity series of metals to predict whether a reaction will occur.

Reference: Section 17.4

115. The following reactions were attempted with the indicated results.

Ca + Pb(NO₃)₂ → Pb + Ca(NO₃)₂

Pb + Fe(NO₃)₂ → NO REACTION

Ca + Fe(NO₃)₂ → Fe + Ca(NO₃)₂

2 Li + Ca(NO₃)₂ → Ca + 2 LiNO₃

Ag + Pb(NO₃)₂ → NO REACTION

Use the results of these reactions to prepare an activity series for the metals Ca, Pb, Fe, Ag, and Li. Place the most active metal at the top and the least active at the bottom.

Ca

Fe

Pb

Ag Least Active

Difficulty: hard

Learning Objective 1: Use the activity series of metals to predict whether a reaction will occur.

Reference: Section 17.4

116. Explain why in a voltaic cell the anode is negative and the cathode is positive.

Difficulty: hard

Learning Objective 1: Compare the reactions and functions of electrolytic and voltaic cells.

Reference: Section 17.5

117. Balance the following redox reaction is acidic solution and calculate the mass of iodine produced from the reaction of 100.0 mL of an aqueous solution that is 0.125 M in with 100.0 mL of a an aqueous solution that is 0.125 M in .

Difficulty: hard

Learning Objective 1: Balance equations for ionic oxidation–reduction reactions.

Reference: Section 17.3