Central Science: Chapter 20

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1

Which element is oxidized in the reaction below?
Fe(CO)5 (l) + 2HI (g) → Fe(CO)4I2 (s) + CO (g) + H2 (g)

A) C
B) O
C) H
D) Fe
E) I

D

2

Which element is oxidized in the reaction below?
Fe2+ + H+ + Cr2O72- → Fe3+ + Cr3+ + H2O

A) Cr
B) O
C) H
D) Fe

D

3

Which element is oxidized in the reaction below?
I- + MnO4- + H+ → I2 + MnO2 + H2O

A) H
B) I
C) O
D) Mn

B

4

Which of the following reactions is a redox reaction?

(a) K2CrO4 + BaCl2 → BaCrO4 + 2KCl
(b) Pb22+ + 2Br- → PbBr
(c) Cu + S → CuS

A) (a) only
B) (b) only
C) (c) only
D) (a) and (c)
E) (b) and (c)

C

5

Which one of the following reactions is a redox reaction?
A) NaOH + HCl → NaCl + H2O
B) Pb2+ + 2Cl- → PbCl2
C) AgNO3 + HCl → HNO3 + AgCl
D) None of the above is a redox reaction.

D

6

Which substance is the oxidizing agent in the following reaction?
Fe2S3 + 12HNO3 → 2Fe(NO3)3 + 3S + 6NO2 + 6H2O

A) HNO3
B) S
C) NO2
D) Fe2S3
E) H2O

A

7

What is the coefficient of the permanganate ion when the following equation is balanced?
MnO4- + Br- → Mn2+ + Br2 (acidic solution)

A) 1
B) 2
C) 3
D) 5
E) 4

B

8

What is the coefficient of the dichromate ion when the following equation is balanced?
Fe2+ + Cr2O72- → Fe3+ + Cr3+ (acidic solution)

A) 1
B) 2
C) 3
D) 5
E) 6

A

9

What is the coefficient of Fe3+ when the following equation is balanced?
CN- + Fe3+ → CNO- + Fe2+ (basic solution)

A) 1
B) 2
C) 3
D) 4
E) 5

B

10

Which transformation could take place at the anode of an electrochemical cell?
A) Cr2O72- → Cr2+
B) F2 to F-
C) O2 to H2O
D) HAsO2 to As
E) None of the above could take place at the anode.

E

11

The purpose of the salt bridge in an electrochemical cell is to ________.
A) maintain electrical neutrality in the half-cells via migration of ions
B) provide a source of ions to react at the anode and cathode
C) provide oxygen to facilitate oxidation at the anode
D) provide a means for electrons to travel from the anode to the cathode
E) provide a means for electrons to travel from the cathode to the anode

A

12

Which transformation below is an example of an oxidation in an electrochemical cell?
A) CO2 → C2O42-
B) VO2+ → VO2+
C) NO → NO3-
D) H2AsO4 → H3AsO3
E) O2 → H2O2

C

13

Which transformation could take place at the cathode of an electrochemical cell?
A) MnO2 → MnO4-
B) Br2 → BrO3-
C) NO → HNO2
D) HSO4- → H2SO3
E) Mn2+ → MnO4-

D

14
card image

Which of the halogens in Table 20.1 is the strongest oxidizing agent?
A) Cl2
B) Br2
C) F2
D) I2
E) All of the halogens have equal strength as oxidizing agents.

C

15

Which one of the following types of elements is most likely to be a good oxidizing agent?
A) alkali metals
B) lanthanides
C) alkaline earth elements
D) transition elements
E) halogens

E

16

Which one of the following is the best oxidizing agent?
A) H2
B) Na
C) O2
D) Li
E) Ca

C

17
card image

Which of the following reactions will occur spontaneously as written?
A) Sn4+ (aq) + Fe3+ (aq) → Sn2+ (aq) + Fe2+ (aq)
B) 3Fe (s) + 2Cr3+ (aq) → 2Cr (s) + 3Fe2+ (aq)
C) Sn4+ (aq) + Fe2+ (aq) → Sn2+ (aq) + Fe (s)
D) 3Sn4+ (aq) + 2Cr (s) → 2Cr3+ (aq) + 3Sn2+ (aq)
E) 3Fe2+ (aq) → Fe (s) + 2Fe3+ (aq)

D

18

Which of the following reactions will occur spontaneously as written?
A) 3Fe2+ (aq) + Cr3+ (aq) → Cr (s) + 3Fe3+ (aq)
B) 2Cr3+ (aq) + 3Sn2+ (aq) → 3Sn4+ (aq) + 2Cr (s)
C) Sn4+ (aq) + Fe2+ (s) → Sn2+ (aq) + Fe (s)
D) Sn2+ (aq) + Fe2+ (s) → Sn4+ (aq) + Fe3+ (aq)
E) 2Cr (s) + 3Fe2+ (s) → 3Fe (s) + 2Cr3+ (aq)

E

19

Consider an electrochemical cell based on the reaction:

2H+ (aq) + Sn (s) → Sn2+ (aq) + H2 (g)

Which of the following actions would change the measured cell potential?
A) increasing the pH in the cathode compartment
B) lowering the pH in the cathode compartment
C) increasing the [Sn2+] in the anode compartment
D) increasing the pressure of hydrogen gas in the cathode compartment
E) Any of the above will change the measure cell potential.

E

20

Consider an electrochemical cell based on the reaction:
2H+ (aq) + Sn (s) → Sn2+ (aq) + H2 (g)
Which of the following actions would not change the measured cell potential?
A) lowering the pH in the cathode compartment
B) addition of more tin metal to the anode compartment
C) increasing the tin (II) ion concentration in the anode compartment
D) increasing the pressure of hydrogen gas in the cathode compartment
E) Any of the above will change the measured cell potential.

B

21

What is the anode in an alkaline battery?
A) MnO2
B) KOH
C) Zn powder
D) Mn2O3
E) Pt

C

22

What is the cathode in an alkaline battery?
A) MnO2
B) KOH
C) Zn powder
D) Mn2O3
E) Pt

A

23

What is being reduced at the cathode in the hydrogen fuel cell?
A) O2
B) KOH
C) Li
D) H2
E) Pt

A

24

In a lead-acid battery, the electrodes are consumed. In this battery, ________.
A) the anode is Pb
B) the anode is PbSO4
C) the anode is PbO2
D) the cathode is PbSO4
E) the cathode is Pb

A

25

Which of the statements about cathodic protection of a metal pipe against corrosion is correct?
A) The metal pipe is protected by attaching an active metal to make the pipe the cathode in an electrochemical cell
B) The metal pipe is protected by coating the pipe with another metal whose standard reduction potential is less negative than that of the pipe
C) The metal pipe is protected by attaching a dry cell to reduce any metal ions which might be formed
D) The metal pipe is protected by attaching an active metal to make the pipe the anode in an electrochemical cell
E) The metal pipe is protected by coating the pipe with a fluoropolymer to act as a source of fluoride ion (since the latter is so hard to oxidize)

A

26

One of the differences between a voltaic cell and an electrolytic cell is that in an electrolytic cell, ________.
A) an electric current is produced by a chemical reaction
B) electrons flow toward the anode
C) a nonspontaneous reaction is forced to occur
D) O2 gas is produced at the cathode
E) oxidation occurs at the cathode

C

27

The loss of electrons by an element is called ________.
A) fractionation
B) reduction
C) disproportionation
D) oxidation
E) sublimation

D

28

Which element is oxidized in the following reaction?

Cr2O72- + 6S2O32- + 14H+ → 2Cr3+ + 3S4O62- + 7H2O

A) S4O62-
B) Cr
C) H
D) O
E) S

E

29

Which element is reduced in the following reaction?

Cr2O72- + 6S2O32- + 14H+ → 2Cr3+ + 3S4O62- + 7H2O

A) H
B) Cr
C) O
D) S
E) S4O62-

B

30

________ is the reducing agent in the reaction below.
Cr2O72- + 6S2O32- + 14H+ → 2Cr3+ + 3S4O62- + 7H2O

A) Cr2O72-
B) S2O32-
C) H+
D) Cr3+
E) S4O62-

B

31

________ is the reducing agent in the reaction below.
Na(s) + 2Cl2(g) → 2NaCl(s)

A) Cl2
B) NaCl
C) Na+
D) Na
E) Cl-

D

32

________ is the oxidizing agent in the reaction below.
Na(s) + 2Cl2(g) → 2NaCl(s)

A) Na+
B) Cl-
C) Na
D) NaCl
E) Cl2

E

33

Which substance is serving as the oxidizing agent in the following reaction?
CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)

A) H2O
B) CH4
C) O2
D) CO2
E) The reaction above is not a redox reaction

C

34

Which substance is the oxidizing agent in the reaction below?
Pb + PbO2 + 2H2SO4 → 2PbSO4 + 2H2O

A) Pb
B) PbSO4
C) H2SO4
D) PbO2
E) H2O

D

35

Which substance does not undergo oxidation or reduction in the reaction below?
Pb + PbO2 + 2H2SO4 → 2PbSO4 + 2H2O

A) Pb
B) H2SO4
C) PbO2
D) PbSO4
E) The reaction above is not a redox reaction

B

36

What is the oxidation number of chromium in K2Cr2O7?
A) +3
B) +12
C) +6
D) +7
E) +14

C

37

What is the oxidation number of oxygen in H2O2?
A) 0
B) +1
C) +2
D) -1
E) -2

D

38

What is the oxidation number of manganese in KMnO4?
A) +1
B) +2
C) +7
D) +4
E) +5

C

39

What is the oxidation number of manganese in MnO2?
A) +3
B) +2
C) +1
D) +4
E) +7

D

40

What is the oxidation number of oxygen in K2O2?
A) -2
B) +1
C) -1
D) +2
E) -1/2

C

41

________ electrons appear in the following half-reaction when it is balanced.

S4O62- → 2S2O32-

A) 6
B) 2
C) 4
D) 1
E) 3

B

42

The balanced half-reaction in which chlorine gas is reduced to the aqueous chloride ion is a ________ process.
A) one-electron
B) two-electron
C) four-electron
D) three-electron
E) six-electron

B

43

The balanced half-reaction in which dichromate ion is reduced to chromium metal is a ________ process.
A) two-electron
B) six-electron
C) three-electron
D) four-electron
E) twelve-electron

E

44

The balanced half-reaction in which ethanol, CH3CH2OH, is oxidized to ethanoic acid, CH3COOH.
is a ________ process.
A) twelve-electron
B) three-electron
C) four-electron
D) six-electron
E) two-electron

C

45

The balanced half-reaction in which sulfate ion is reduced to sulfite ion is a ________ process.
A) four-electron
B) one-electron
C) two-electron
D) three-electron
E) six-electron

C

46

The electrode at which oxidation occurs is called the ________.
A) oxidizing agent
B) cathode
C) reducing agent
D) anode
E) voltaic cell

D

47

The half-reaction occurring at the anode in the balanced reaction shown below is ________.

3MnO4- (aq) + 24H+ (aq) + 5Fe (s) → 3Mn2+ (aq) + 5Fe3+ (aq) + 12H2O (l)

A) MnO4- (aq) + 8H+ (aq) + 5e- → Mn2+ (aq) + 4H2O (l)
B) 2MnO4- (aq) + 12H+ (aq) + 6e- → 2Mn2+ (aq) + 3H2O (l)
C) Fe (s) → Fe3+ (aq) + 3e-
D) Fe (s) → Fe2+ (aq) + 2e-
E) Fe2+ (aq) → Fe3+ (aq) + e-

C

48

The half-reaction occurring at the cathode in the balanced reaction shown below is ________.

3MnO4- (aq) + 24H+ (aq) + 5Fe (s) → 3Mn2+ (aq) + 5Fe3+ (aq) + 12H2O (l)

A) MnO4- (aq) + 8H+ (aq) + 5 → Mn2+ (aq) + 4H2O (l)
B) 2MnO4- (aq) + 12H+ (aq) + 6e- → 2Mn2+ (aq) + 3H2O (l)
C) Fe (s) → Fe3+ (aq) + 3e-
D) Fe (s) → Fe2+ (aq) + 2e-
E) Fe2+ (aq) → Fe3+ (aq) + e-

A

49

In a voltaic cell, electrons flow from the ________ to the ________.
A) salt bride, anode
B) anode, salt bridge
C) cathode, anode
D) salt bridge, cathode
E) anode, cathode

E

50

The reduction half reaction occurring in the standard hydrogen electrode is ________.
A) H2 (g, 1 atm) → 2H+ (aq, 1M) + 2e-
B) 2H+ (aq) + 2O → H2O (l)
C) O2 (g) + 4H+ (aq) + 4e- → 2H2O (l)
D) 2H+ (aq, 1M) + 2e- → H2 (g, 1 atm)
E) 2H+ (aq, 1M) + Cl2 (aq) → 2HCl (aq)

D

51

1V = ________.
A) 1 amp ∙ s
B) 1 J/s
C) 96485 C
D) 1 J/C
E) 1 C/J

D

52

The less ________ the value of E°red, the lower the driving force for reduction.
A) negative
B) exothermic
C) positive
D) endothermic
E) extensive

C

53
card image

The standard cell potential (E°cell) for the voltaic cell based on the reaction below is ________ V.
Sn2+ (aq) + 2Fe3+ (aq) → 2Fe2+ (aq) + Sn4+ (aq)

A) +0.46
B) +0.617
C) +1.39
D) -0.46
E) +1.21

B

54

The standard cell potential (E°cell) for the voltaic cell based on the reaction below is ________ V.

Cr (s) + 3Fe3+ (aq) → 3Fe2+ (aq) + Cr3+ (aq)

A) -1.45
B) +2.99
C) +1.51
D) +3.05
E) +1.57

C

55

The standard cell potential (E°cell) for the voltaic cell based on the reaction below is ________ V.
2Cr (s) + 3Fe2+ (aq) → 3Fe (s) + 2Cr3+ (aq)

A) +0.30
B) +2.80
C) +3.10
D) +0.83
E) -0.16

A

56

The standard cell potential (E°cell) for the voltaic cell based on the reaction below is ________ V.
3Sn4+ (aq) + 2Cr (s) → 2Cr3+ (aq) + 3Sn2+ (aq)

A) +1.94
B) +0.89
C) +2.53
D) -0.59
E) -1.02

B

57

The relationship between the change in Gibbs free energy and the emf of an electrochemical cell is given by ________.
A) ΔG = -nF/E
B) ΔG = -E/nF
C) ΔG = -nFE
D) ΔG = -nRTF
E) ΔG = -nF/ERT

C

58

The standard cell potential (E°cell) of the reaction below is +0.126 V. The value of ΔG for the reaction is ________ kJ/mol.
Pb (s) + 2H+(aq) → Pb2+ (aq) + H2 (g)

A) -24.3
B) +24.3
C) -12.6
D) +12.6
E) -50.8

A

59

The standard cell potential (E°cell) of the reaction below is -0.55 V. The value of ΔG for the reaction is ________ J/mol.
I2 (s) + 2Br- (aq) → 2I- (aq) + Br2 (l)

A) 0.54
B) 0.55
C) 5.5 × 10-6
D) 1.1 × 105
E) none of the above

D

60

The standard cell potential (E°cell) of the reaction below is -0.34 V. The value of ΔG for the reaction is ________ kJ/mol.
Cu (s) + 2H+ (aq) → Cu2+ (aq) + H2 (g)

A) -0.34
B) +66
C) -130
D) +130
E) none of the above

B

61

The standard cell potential (E°cell) of the reaction below is +1.34 V. The value of ΔG for the reaction is ________ kJ/mol.
3 Cu (s) + 2 MnO4- (aq) + 8H+ (aq) → 3 Cu2+ (aq) + 2 MnO2 (s) + 4 H2O (l)

A) -24.3
B) +259
C) -259
D) +776
E) -776

E

62

The lead-containing reactant(s) consumed during recharging of a lead-acid battery is/are ________.
A) Pb (s) only
B) PbO2 (s) only
C) PbSO4 (s) only
D) both PbO2 (s) and PbSO4 (s)
E) both Pb (s) and PbO2 (s)

C

63

Galvanized iron is iron coated with ________.
A) magnesium
B) zinc
C) chromium
D) phosphate
E) iron oxide

B

64

Corrosion of iron is retarded by ________.
A) the presence of salts
B) high pH conditions
C) low pH conditions
D) both the presence of salts and high pH conditions
E) both the presence of salts and low pH conditions

B

65

What is the oxidation number of bromine in the HBrO molecule?
A) +1
B) +2
C) 0
D) -1
E) -2

A

66

What is the oxidation number of nitrogen in the NH2OH molecule?
A) -1
B) -2
C) -3
D) 0
E) +1

A

67

What is the oxidation number of sulfur in the S2O32– ion?
A) +2
B) +1
C) 0
D) -1
E) -2

A

68

Which substance is the oxidizing agent in the reaction below?
Fe(CO)5 (l) + 2HI (g) → Fe(CO)4I2 (s) + CO (g) + H2 (g)

A) HI
B) Fe(CO)5
C) Fe(CO)4I2
D) CO
E) H2

A

69

Which element is reduced in the reaction below?
Fe2+ + H+ + Cr2O72- → Fe3+ + Cr3+ + H2O

A) Cr
B) Fe
C) H
D) O

A

70

Which element is oxidized in the reaction below?
I- + MnO4- + H+ → I2 + MnO2 + H2O

A) I
B) Mn
C) O
D) H

A

71

Which element is reduced in the following reaction?
Fe2S3 + 12HNO3 → 2Fe(NO3)3 + 3S + 6NO2 + 6H2O

A) N
B) S
C) H
D) O
E) NO2

A

72

What is the oxidation number of phosphorous in the PH3 molecule?
A) -3
B) -4
C) -5
D) +1
E) 0

A

73

What is the correct coefficient for the electrons in the following half-reaction:

Ni6+ + ___e– → Ni

A) 6
B) 1
C) 2
D) 3
E) 5

A

74

In the galvanic cell using the redox reaction below, the reduction half-reaction is ________.

Zn (s) + Cu2+ (aq) → Zn2+ (aq) + Cu (s)

A) Cu2+ + 2e– → Cu
B) Zn → Zn2+ + 2e–
C) Cu2+ → Cu + 2e–
D) Zn + 2e– → Zn2+

A

75

In the electrochemical cell using the redox reaction below, the cathode half-reaction is ________.

2H+ (s) + Sn (s) → Sn2+ (aq) + H2 (g)

A) 2H+ + 2e– → H2
B) Sn → Sn2+ + 2e–
C) 2H+ → H2 + 2e–
D) Sn + 2e– → Sn2+
E) Sn + 2e- → H2

A

76

In the electrochemical cell using the redox reaction below, the oxidation half reaction is ________.

Sn4+ (aq) + Fe (s) → Sn2+ (aq) + Fe2+ (aq)

A) Sn4+ + 2e– → Sn2+
B) Fe → Fe2+ + 2e–
C) Sn4+ → Sn2+ + 2e–
D) Fe + 2e– → Fe2+
E) Fe + 2e- → Sn2+

B

77

The standard cell potential (E°) of a voltaic cell constructed using the cell reaction below is 0.76 V:

Zn (s) + 2H+ (aq) → Zn2+ (aq) +H2 (g)

With PH2 = 1.0 atm and [Zn2+] = 1.0 M, the cell potential is 0.53 V. At 25 °C, the concentration of H+ in the cathode compartment is ________ M.
A) 1.3 × 10-4
B) 1.7 × 10-8
C) 1.1 × 10-2
D) 7.7 × 103
E) 1.3 × 10-11

A

78

A voltaic cell is constructed with two silver-silver chloride electrodes, where the half-reaction is

AgCl (s) + e- → Ag (s) + Cl- (aq) E° = +0.222 V

The concentrations of chloride ion in the two compartments are 0.0100 M and 1.55 M, respectively. At 25 °C, the cell emf is ________ V.
A) 0.216
B) 0.130
C) 0.00143
D) 34.4
E) 0.228

B

79

The standard cell potential (E°cell) for the reaction below is +0.63 V. At 25 °C, the cell potential for this reaction is ________ V when [Zn2+] = 3.0 M and [Pb2+] = 2.0 x 10-4 M.
Pb2+ (aq) + Zn (s) → Zn2+ (aq) + Pb (s)

A) 0.51
B) 0.86
C) 0.40
D) 0.75
E) 0.63

A

80

The standard cell potential (E°cell) for the reaction below is +1.10 V. The cell potential for this reaction is ________ V when the concentration of [Cu2+] = 1.0 x 10-5 M AND [Zn2+] = 3.0 M.
Zn (s) + Cu2+ (aq) → Cu (s) + Zn2+ (aq)

A) 1.42
B) 1.26
C) 0.94
D) 0.78
E) 1.10

C

81

A voltaic cell is constructed with two Zn2+-Zn electrodes, where the half-reaction is

Zn2+ + 2e- → Zn (s) E° = -0.763 V

The concentrations of zinc ion in the two compartments are 4.50 M and 1.11 × 10-2 M, respectively. The cell emf is ________ V.
A) -1.88 × 10-3
B) -309
C) 0.0772
D) 0.154
E) -0.761

C

82

The standard emf for the cell using the overall cell reaction below is +2.20 V:

2Al (s) + 3I2 (s) → 2Al3+ (aq) + 6I- (aq)

The emf generated by the cell when [Al3+] = 3.5 × 10-3 M and [I-] = 0.30 M is ________ V.
A) 2.20
B) 2.28
C) 2.12
D) 2.36
E) 2.23

B

83

The standard emf for the cell using the overall cell reaction below is +0.48 V:

Zn (s) + Ni2+ (aq) → Zn2+ (aq) + Ni (s)

The emf generated by the cell when [Ni2+] = 0.100 M and [Zn2+] = 2.25 M is ________ V.
A) 0.56
B) 0.50
C) 0.44
D) 0.40
E) 0.52

C

84

How many kilowatt-hours of electricity are used to produce 4.50 kg of magnesium in the electrolysis of molten MgCl2 with an applied emf of 5.00 V?
A) 0.0201
B) 0.0496
C) 12.4
D) 49.6
E) 24.8

D

85

The most useful ore of aluminum is bauxite, in which Al is present as hydrated oxides, Al2O3 . xH2O. The number of kilowatt-hours of electricity required to produce 3.00 kg of aluminum from electrolysis of compounds from bauxite is ________ when the applied emf is 4.50 V.
A) 0.0249
B) 0.0402
C) 26.8
D) 13.4
E) 40.2

E

86

The town of Natrium, West Virginia, derives its name from the sodium produced in the electrolysis of molten sodium chloride (NaCl) mined from ancient salt deposits. The number of kilowatt-hours of electricity required to produce 4.50 kg of metallic sodium from the electrolysis of molten NaCl(s) is ________ when the applied emf is 5.00 V.
A) 26.2
B) 0.0381
C) 0.0262
D) 52.5
E) 13.1

A

87

The electrolysis of molten AlCl3 for 2.50 hr with an electrical current of 12.0 A produces ________ g of aluminum metal.
A) 90.7
B) 0.373
C) 2.80 × 10-3
D) 10.1
E) 30.2

D

88

How many seconds are required to produce 5.00 g of aluminum metal from the electrolysis of molten AlCl3 with an electrical current of 15.0 A?
A) 27.0
B) 9.00
C) 1.19E × 103
D) 2.90 × 105
E) 3.57 × 103

E

89

How many minutes will it take to plate out 2.19 g of chromium metal from a solution of Cr3+ using a current of 19.5 amps in an electrolytic cell?
A) 10.4
B) 625
C) 208
D) 3.47
E) 31.2

A

90

What current (in A) is required to plate out 1.22 g of nickel from a solution of Ni2+ in 0.50 hour?
A) 65.4
B) 8.02 × 103
C) 2.22
D) 12.9
E) 4.46

C

91

How many grams of Ca metal are produced by the electrolysis of molten CaBr2 using a current of 30.0 amp for 8.0 hours?
A) 17.9
B) 359
C) 0.0622
D) 179
E) 89.7

D

92

How many grams of Cu are obtained by passing a current of 12 A through a solution of CuSO4 for 15 minutes?
A) 0.016
B) 3.6
C) 7.1
D) 14
E) 1.8

B

93

How many seconds are required to produce 1.0 g of silver metal by the electrolysis of a AgNO3 solution using a current of 60 amps?
A) 5.4 × 104
B) 3.2 × 103
C) 15
D) 3.7 × 10-5
E) 30

C

94

How many grams of copper will be plated out by a current of 2.3 A applied for 35 minutes to a 0.50 M solution of copper (II) sulfate?
A) 1.6
B) 3.2
C) 1.8 × 10-2
D) 3.6 × 10-2
E) 0.019

A

95

How much time (min) will it require to plate out 4.56 g of Ni metal from a solution of Ni2+ using a current of 35.5 amps in an electrolytic cell?
A) 4.55
B) 3.52
C) 211
D) 7.04
E) 422

D

96

How many minutes will it take to plate out 16.22 g of Al metal from a solution of Al3+ using a current of 14.6 amps in an electrolytic cell?
A) 53.0
B) 66.2
C) 153
D) 199
E) 11900

D

97

Based on standard reduction potentials, the most difficult species to reduce and the poorest oxidizing agent is ________.

lithium ion; Li+

98

At constant ________ and ________ the Gibbs free energy value is a measure of the spontaneity of a process.

temperature, pressure

99

In the formula ΔG = -nFE, n is the ________.

number of electrons transferred in the reaction

100

Define the Nernst equation.

the dependence of cell emf on concentration

101

The potential (E) to move K+ from the extracellular fluid to the intracellular fluid necessitates work. The sign for this potential is ________.

negative

102

The ________ of the alkaline battery is powdered zinc in a gel that contacts potassium hydroxide.

anode

103

The major product of a ________ fuel cell is water.

hydrogen

104

What is a galvanized iron nail?

when an iron nail is coated with a thin layer of zinc to protect against corrosion

105

Define a coulomb.

the quantity of charge passing a point in a circuit in one second when the current is one ampere

106

Calculate the number of grams of aluminum produced in 1.00 hour by electrolysis of AlCl3 at a current of 10.0 A.

3.36

107

The electrode where reduction occurs is called the anode.

false

108

In a voltaic cell electrons flow from the anode to the cathode.

true

109

When the cell potential is negative in a voltaic cell, the cell reaction will not proceed spontaneously.

true

110

The standard reduction potential, E°red, is proportional to the stoichiometric coefficient.

false

111

The standard reduction potential of X is 1.23 V and that of Y is -0.44 V; therefore X is oxidized by Y.

false

112

The lithium ion battery has more energy per unit mass than nickel-cadmium batteries.

true

113

In a half reaction, the amount of a substance that is reduced or oxidized is directly proportional to the number of electrons generated in the cell.

true

114

The amount of a substance that is reduced or oxidized is inversely proportional to the number of electrons produced in a cells half reaction.

false