Question 1

A voltaic cell consists of a Ag/Ag+ electrode (E° = 0.80 V)  and a Fe2+/Fe3+ electrode (E° = 0.77 V)  with the following initial molar concentrations: [Fe2+] = 0.30 M; [Fe3+] = 0.10 M; [Ag+] = 0.30 M. What is the equilibrium concentration of Fe3+? (Assume the anode and cathode solutions are of equal volume, and a temperature of 25°C.)

Accepted Answer

A)  0.030 M
B)  0.043 M
C)  0.085 M
D)  0.11 M
E)  0.17 MF) A) and B)
G) A) and D)

Question 2

What mass of copper will be deposited when 18.2 A are passed through a CuSO4 solution for 45.0 minutes?

Accepted Answer

A)  16.2 g
B)  33.4 g
C)  40.6 g
D)  81.3 g
E)  163 gF) A) and B)
G) A) and C)

Question 3

Calculate E°cell and indicate whether the overall reaction shown is spontaneous or nonspontaneous. Co3+(aq)  + e− ⇄ Co2+(aq)  E° = 1.82 V
MnO4−(aq)  + 2H2O(l)  + 3e- ⇄ MnO2(s)  + 4OH−(aq)  E° = 0.59 V
Overall reaction:
MnO4−(aq)  + 2H2O(l)  + 3Co2+(aq)  → MnO2(s)  + 3Co3+(aq)  + 4OH−(aq)

Accepted Answer

A)  E° cell = -1.23 V, spontaneous
B)  E° cell = -1.23 V, nonspontaneous
C)  E° cell = 1.23 V, spontaneous
D)  E° cell = 1.23 V, nonspontaneous
E)  E° cell = -0.05 V, nonspontaneousF) B) and D)
G) A) and C)

Question 4

A voltaic cell prepared using zinc and iodine has the following cell notation. Zn(s)  | Zn2+(aq)  || I−(aq)  | I2(s)  | C(graphite) 
Which of the following equations correctly represents the balanced, spontaneous, cell reaction?

Accepted Answer

A)  2I −( aq) + Zn 2+( aq) → I 2( s) + Zn( s) 
B)  I 2( s) + Zn( s) → 2I −( aq) + Zn 2+( aq) 
C)  2I −( aq) + Zn( s) → I 2( s) + Zn 2+( aq) 
D)  I 2( s) + Zn 2+( aq) → 2I −( aq) + Zn( s) 
E)  None of these choices are correct.F) D) and E)
G) A) and B)

Question 5

Chromium metal is electroplated from acidic aqueous solutions containing the dichromate ion, Cr2O72-. What is the minimum time needed to plate out 10.0 g of chromium metal from such a solution, if the current is 50.0 A?

Accepted Answer

A)  6.2 minutes
B)  12.4 minutes
C)  18.6 minutes
D)  24.7 minutes
E)  37.1 minutesF) A) and D)
G) A) and C)

Question 6

A voltaic cell prepared using aluminum and nickel has the following cell notation. Al(s)  | Al3+(aq)  || Ni2+(aq)  | Ni(s) 
Which of the following represents the correctly balanced spontaneous reaction equation for the cell?

Accepted Answer

A)  Ni 2+( aq) + Al( s) → Al 3+( aq) + Ni( s) 
B)  3Ni 2+( aq) + 2Al( s) → 2Al 3+( aq) + 3Ni( s) 
C)  Ni( s) + Al 3+( aq) → Ni 2+( aq) + Al( s) 
D)  3Ni( s) + 2Al 3+( aq) → 3Ni 2+( aq) + 2Al( s) 
E)  None of these choices are correct.F) A) and D)
G) D) and E)

Question 7

Which one of the following statements relating to the glass electrode is correct?

Accepted Answer

A)  The glass electrode detects hydrogen gas.
B)  The glass of a glass electrode serves to conduct electrons.
C)  When pH is measured, only a single electrode, the glass electrode, need be used.
D)  The potential of the glass electrode varies linearly with the pH of the solution.
E)  None of these choices are correct.F) C) and D)
G) None of the above

Question 8

Given that E° for X + e- → Y is greater than E° for A + 2e- → B, it is correct to say that, under standard conditions

Accepted Answer

A)  X will oxidize A.
B)  Y will oxidize A.
C)  Y will reduce A.
D)  B will oxidize X.
E)  B will reduce X.F) C) and D)
G) A) and E)

Question 9

A battery that cannot be recharged is a

Accepted Answer

A)  fuel cell.
B)  primary battery.
C)  secondary battery.
D)  simple battery.
E)  flow battery.F) C) and D)
G) None of the above

Question 10

Examine the following half-reactions and select the strongest oxidizing agent among the substances. [PtCl4]2−(aq)  + 2e− ⇄ Pt(s)  + 4Cl−(aq)  E° = 0.755 V
RuO4(s)  + 8H+(aq)  + 8e− ⇄ Ru(s)  + 4H2O(l)  E° = 1.038 V
FeO42−(aq)  + 8H+(aq)  + 3e− ⇄ Fe3+(aq)  + 4H2O(l)  E° = 2.07 V
H4XeO6(aq)  + 2H+(aq)  + 2e− ⇄ XeO3(aq)  + 3H2O(l)  E° = 2.42 V

Accepted Answer

A)  [PtCl 4] 2-( aq) 
B)  RuO 4( s) 
C)  HFeO 4− ( aq) 
D)  H 4X eO 6( aq) 
E)  Cl −( aq) F) All of the above
G) A) and D)

Question 11

A secondary cell (battery) can operate either as a galvanic or an electrolytic cell.

Accepted Answer

A) True 
 B)False

Question 12

Which of the following statements about voltaic and electrolytic cells is correct?

Accepted Answer

A)  The electrons in the external wire flow from cathode to anode in both types of cell.
B)  Oxidation occurs at the cathode only in a voltaic cell.
C)  The free energy change, Δ G, is negative for an electrolytic cell.
D)  The cathode is labeled as positive (+) in a voltaic cell but negative (-) in an electrolytic cell.
E)  Reduction occurs at the anode in an electrolytic cell.F) A) and E)
G) A) and B)

Question 13

Calculate ΔG° for the oxidation of 3 moles of copper by nitric acid. Cu2+(aq)  + 2e− ⇄ Cu(s)  E° = 0.34 V
NO3−(aq)  + 4H+(aq)  + 3e− ⇄ NO(g)  + 2H2O(l)  E° = 0.957 V

Accepted Answer

A)  −120 kJ
B)  −180 kJ
C)  −240 kJ
D)  −300 kJ
E)  −360 kJF) D) and E)
G) A) and C)

Question 14

Which of the following solids is commonly used as an inactive electrode in electrochemical cells?

Accepted Answer

A)  Zinc
B)  Graphite
C)  Copper
D)  Iron
E)  SodiumF) None of the above
G) All of the above

Question 15

A salt bridge provides a path for electrons to move between the anode and cathode compartments of a voltaic cell.

Accepted Answer

A) True 
 B)False

Question 16

Which of the following elements can be isolated by electrolysis of the aqueous salt shown?

Accepted Answer

A)  Phosphorus from K 3PO 4( aq) 
B)  Sodium from NaBr( aq) 
C)  Aluminum from AlCl 3( aq) 
D)  Fluorine from KF( aq) 
E)  Iodine from NaI( aq) F) D) and E)
G) All of the above

Question 17

Electrolytic cells utilize electrical energy to drive nonspontaneous redox reactions.

Accepted Answer

A) True 
 B)False

Question 18

What mass of silver will be formed when 15.0 A are passed through molten AgCl for 25.0 minutes?

Accepted Answer

A)  0.419 g
B)  6.29 g
C)  12.6 g
D)  25.2 g
E)  33.4 gF) B) and E)
G) B) and D)

Question 19

What is the E°cell for the cell represented by the combination of the following half-reactions? 2Hg2+(aq)  + 2e- ⇄ Hg22+(aq)  E° = 0.92 V
Cr3+(aq)  + 3e- ⇄ Cr(s)  E° = -0.74 V

Accepted Answer

A)  -0.18 V
B)  0.18 V
C)  1.28 V
D)  1.66 V
E)  2.12 VF) A) and B)
G) D) and E)

Question 20

Which one of the following statements about electrochemical cells is correct?

Accepted Answer

A)  In a salt bridge, current is carried by cations moving toward the anode, and anions toward the cathode.
B)  In the external wire, electrons travel from cathode to anode.
C)  The anode of a voltaic cell is labeled minus (−) .
D)  Oxidation occurs at the cathode, in an electrolytic cell.
E)  None of these choices are correct.F) B) and D)
G) A) and B)

Exam 21: Electrochemistry: Chemical Change and Electrical Work

A salt bridge provides a path for electrons to move between the anode and cathode compartments of a voltaic cell.

Correct Answer
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A voltaic cell prepared using zinc and iodine has the following cell notation. Zn(s) | Zn²⁺(aq) || I⁻(aq) | I₂(s) | C(graphite) Which of the following equations correctly represents the balanced, spontaneous, cell reaction?

Correct Answer
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Which one of the following statements about electrochemical cells is correct?

Correct Answer
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A battery that cannot be recharged is a

Correct Answer
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What mass of silver will be formed when 15.0 A are passed through molten AgCl for 25.0 minutes?

Correct Answer
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Which of the following solids is commonly used as an inactive electrode in electrochemical cells?

Correct Answer
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Chromium metal is electroplated from acidic aqueous solutions containing the dichromate ion, Cr₂O₇²^-. What is the minimum time needed to plate out 10.0 g of chromium metal from such a solution, if the current is 50.0 A?

Correct Answer
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Given that E° for X + e^- → Y is greater than E° for A + 2e^- → B, it is correct to say that, under standard conditions

Correct Answer
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What is the E°_cell for the cell represented by the combination of the following half-reactions? 2Hg²⁺(aq) + 2e^- ⇄ Hg₂²⁺(aq) E° = 0.92 V Cr³⁺(aq) + 3e^- ⇄ Cr(s) E° = -0.74 V

Correct Answer
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Which one of the following statements relating to the glass electrode is correct?

Correct Answer
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Calculate ΔG° for the oxidation of 3 moles of copper by nitric acid. Cu²⁺(aq) + 2e⁻ ⇄ Cu(s) E° = 0.34 V NO₃⁻(aq) + 4H⁺(aq) + 3e⁻ ⇄ NO(g) + 2H₂O(l) E° = 0.957 V

Correct Answer
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Which of the following elements can be isolated by electrolysis of the aqueous salt shown?

Correct Answer
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A secondary cell (battery) can operate either as a galvanic or an electrolytic cell.

Correct Answer
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Electrolytic cells utilize electrical energy to drive nonspontaneous redox reactions.

Correct Answer
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Which of the following statements about voltaic and electrolytic cells is correct?

Correct Answer
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A voltaic cell prepared using aluminum and nickel has the following cell notation. Al(s) | Al³⁺(aq) || Ni²⁺(aq) | Ni(s) Which of the following represents the correctly balanced spontaneous reaction equation for the cell?

Correct Answer
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What mass of copper will be deposited when 18.2 A are passed through a CuSO₄ solution for 45.0 minutes?

Correct Answer
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Exam 21: Electrochemistry: Chemical Change and Electrical Work

A salt bridge provides a path for electrons to move between the anode and cathode compartments of a voltaic cell.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Calculate E°cell and indicate whether the overall reaction shown is spontaneous or nonspontaneous. Co3+(aq) + e− ⇄ Co2+(aq) E° = 1.82 V MnO4−(aq) + 2H2O(l) + 3e- ⇄ MnO2(s) + 4OH−(aq) E° = 0.59 V Overall reaction: MnO4−(aq) + 2H2O(l) + 3Co2+(aq) → MnO2(s) + 3Co3+(aq) + 4OH−(aq)

Correct AnswerverifiedShow Answer

A voltaic cell prepared using zinc and iodine has the following cell notation. Zn(s) | Zn2+(aq) || I−(aq) | I2(s) | C(graphite) Which of the following equations correctly represents the balanced, spontaneous, cell reaction?

Correct AnswerverifiedShow Answer

Which one of the following statements about electrochemical cells is correct?

Correct AnswerverifiedShow Answer

A battery that cannot be recharged is a

Correct AnswerverifiedShow Answer

What mass of silver will be formed when 15.0 A are passed through molten AgCl for 25.0 minutes?

Correct AnswerverifiedShow Answer

Which of the following solids is commonly used as an inactive electrode in electrochemical cells?

Correct AnswerverifiedShow Answer

Chromium metal is electroplated from acidic aqueous solutions containing the dichromate ion, Cr2O72-. What is the minimum time needed to plate out 10.0 g of chromium metal from such a solution, if the current is 50.0 A?

Correct AnswerverifiedShow Answer

Given that E° for X + e- → Y is greater than E° for A + 2e- → B, it is correct to say that, under standard conditions

Correct AnswerverifiedShow Answer

What is the E°cell for the cell represented by the combination of the following half-reactions? 2Hg2+(aq) + 2e- ⇄ Hg22+(aq) E° = 0.92 V Cr3+(aq) + 3e- ⇄ Cr(s) E° = -0.74 V

Correct AnswerverifiedShow Answer

Which one of the following statements relating to the glass electrode is correct?

Correct AnswerverifiedShow Answer

Calculate ΔG° for the oxidation of 3 moles of copper by nitric acid. Cu2+(aq) + 2e− ⇄ Cu(s) E° = 0.34 V NO3−(aq) + 4H+(aq) + 3e− ⇄ NO(g) + 2H2O(l) E° = 0.957 V

Correct AnswerverifiedShow Answer

Which of the following elements can be isolated by electrolysis of the aqueous salt shown?

Correct AnswerverifiedShow Answer

A secondary cell (battery) can operate either as a galvanic or an electrolytic cell.

Correct AnswerverifiedShow Answer

Electrolytic cells utilize electrical energy to drive nonspontaneous redox reactions.

Correct AnswerverifiedShow Answer

Which of the following statements about voltaic and electrolytic cells is correct?

Correct AnswerverifiedShow Answer

A voltaic cell prepared using aluminum and nickel has the following cell notation. Al(s) | Al3+(aq) || Ni2+(aq) | Ni(s) Which of the following represents the correctly balanced spontaneous reaction equation for the cell?

Correct AnswerverifiedShow Answer

What mass of copper will be deposited when 18.2 A are passed through a CuSO4 solution for 45.0 minutes?

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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A voltaic cell prepared using zinc and iodine has the following cell notation. Zn(s) | Zn²⁺(aq) || I⁻(aq) | I₂(s) | C(graphite) Which of the following equations correctly represents the balanced, spontaneous, cell reaction?

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Chromium metal is electroplated from acidic aqueous solutions containing the dichromate ion, Cr₂O₇²^-. What is the minimum time needed to plate out 10.0 g of chromium metal from such a solution, if the current is 50.0 A?

Correct Answer
verified

Given that E° for X + e^- → Y is greater than E° for A + 2e^- → B, it is correct to say that, under standard conditions

Correct Answer
verified

What is the E°_cell for the cell represented by the combination of the following half-reactions? 2Hg²⁺(aq) + 2e^- ⇄ Hg₂²⁺(aq) E° = 0.92 V Cr³⁺(aq) + 3e^- ⇄ Cr(s) E° = -0.74 V

Correct Answer
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Correct Answer
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Calculate ΔG° for the oxidation of 3 moles of copper by nitric acid. Cu²⁺(aq) + 2e⁻ ⇄ Cu(s) E° = 0.34 V NO₃⁻(aq) + 4H⁺(aq) + 3e⁻ ⇄ NO(g) + 2H₂O(l) E° = 0.957 V

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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A voltaic cell prepared using aluminum and nickel has the following cell notation. Al(s) | Al³⁺(aq) || Ni²⁺(aq) | Ni(s) Which of the following represents the correctly balanced spontaneous reaction equation for the cell?

Correct Answer
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What mass of copper will be deposited when 18.2 A are passed through a CuSO₄ solution for 45.0 minutes?

Correct Answer
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