Question 1

When the following redox equation is balanced with smallest whole number coefficients, the coefficient for zinc will be Zn(s)  + ReO4(aq)  → Re(s)  + Zn2+(aq)  (acidic solution)

Accepted Answer

A)   2.
B)   7.
C)   8.
D)   16.
E)   None of these choices are correct.F) C) and E)
G) A) and B)

Question 2

The following half-reactions occur in the mercury battery used in calculators. If E° cell = 1.357 V, calculate the equilibrium constant for the cell reaction at 25°C. (Assume the stoichiometric coefficients in the cell reaction are all equal to 1.)  HgO(s)  + H2O(l)  + 2e-
   cell = 1.357 V, calculate the equilibrium constant for the cell reaction at 25°C. (Assume the stoichiometric coefficients in the cell reaction are all equal to 1.)  HgO(s)  + H2O(l)  + 2e-     Hg(l)  + 2OH-(aq)  ZnO(s)  + H2O(l)  + 2e-     Zn(s)  + 2OH-(aq)  A)  9.4 × 1022 B)  7.5 × 1045 C)  6.4 × 1063 D)  7.8 × 1091 E)  > 9.9 × 1099" class="answers-bank-image d-inline" rel="preload" > Hg(l)  + 2OH-(aq) 
ZnO(s)  + H2O(l)  + 2e-
   cell = 1.357 V, calculate the equilibrium constant for the cell reaction at 25°C. (Assume the stoichiometric coefficients in the cell reaction are all equal to 1.)  HgO(s)  + H2O(l)  + 2e-     Hg(l)  + 2OH-(aq)  ZnO(s)  + H2O(l)  + 2e-     Zn(s)  + 2OH-(aq)  A)  9.4 × 1022 B)  7.5 × 1045 C)  6.4 × 1063 D)  7.8 × 1091 E)  > 9.9 × 1099" class="answers-bank-image d-inline" rel="preload" > Zn(s)  + 2OH-(aq)

Accepted Answer

A)   9.4 × 1022
B)   7.5 × 1045
C)   6.4 × 1063
D)   7.8 × 1091
E)   > 9.9 × 1099F) B) and C)
G) B) and D)

Question 3

Consider the reaction in the lead-acid cell Pb(s)  + PbO2(s)  + 2H2SO4(aq)  → 2PbSO4(aq)  + 2H2O(l) 
For which E° cell = 2.04 V at 298 K. ΔG° for this reaction is

Accepted Answer

A)   -3.94 × 105 kJ.
B)   -3.94 × 102 kJ.
C)   -1.97 × 105 kJ.
D)   -7.87 × 102 kJ.
E)   None of these choices are correct.F) None of the above
G) B) and C)

Question 4

Which one of the following is not a redox reaction?

Accepted Answer

A)   Al(OH) 4(aq)  + 4H(aq)  → Al3+(aq)  + 4H2O(l) 
B)   C6H12O6(s)  + 6O2(g)  → 6CO2(g)  + 6H2O(l) 
C)   Na6FeCl8(s)  + 2Na(l)  → 8NaCl(s)  + Fe(s) 
D)   2H2O2(aq)  → 2H2O(l)  + O2(g) 
E)   CO2(g)  + H2(g)  → CO(g)  + H2O(g) F) A) and B)
G) A) and C)

Question 5

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) D) and E)
G) C) and E)

Question 6

Which component of the following cell notation is the anode? P |  || R | S

Accepted Answer

A)   P
B)   
C)   R
D)   S
E)   One of the | symbols is the anode.F) A) and D)
G) C) and E)

Question 7

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 reactions occurs at the anode?

Accepted Answer

A)   Al(s)  → Al3+(aq)  + 3e-
B)   Al3+(aq)  + 3e → Al(s) 
C)   Ni(s)  → Ni2+(aq)  + 2e-
D)   Ni2+(aq)  + 2e- → Ni(s) 
E)   None of these choices are correct.F) B) and D)
G) A) and D)

Question 8

A voltaic cell consists of a Cd/Cd2+ electrode (E° = -0.40 V)  and a Fe/Fe2+ electrode (E° = -0.44 V) . If Ecell = 0 and the temperature is 25°C, what is the ratio [Fe2+]/[Cd2+]?

Accepted Answer

A)   2 × 101
B)   1 × 101
C)   1
D)   1 × 10-1
E)   5 × 10-2F) B) and C)
G) A) and E)

Question 9

The value of E° cell for the reaction 2Cr3+(aq)  + 6Hg(l)  → 2Cr(s)  + 3Hg22+(aq) 
Is 1.59 V. Calculate ΔG° for the reaction.

Accepted Answer

A)   -921 kJ
B)   -767 kJ
C)   -460 kJ
D)   -307 kJ
E)   None of these choices are correct.F) B) and E)
G) C) and E)

Question 10

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

Accepted Answer

A) True 
 B)False

Question 11

What product forms at the anode during the electrolysis of molten NaBr?

Accepted Answer

A)   Na+(l) 
B)   Na(l) 
C)   Br-(l) 
D)   Br3-(l) 
E)   Br2(g) F) C) and D)
G) B) and D)

Question 12

Calculate E° cell and indicate whether the overall reaction shown is spontaneous or nonspontaneous. O2(g)  + 4H+(aq)  + 4e-
   cell and indicate whether the overall reaction shown is spontaneous or nonspontaneous. O2(g)  + 4H+(aq)  + 4e-     2H2O(l)  E° = 1.229 V Al3+(aq)  + 3e-     Al(s)  E° = -1.662 V Overall reaction: 4Al(s)  + 3O2(g)  + 12H+(aq)  → 4Al3+(aq)  + 6H2O(l)  A)  E° cell = -2.891 V, nonspontaneous B)  E° cell = -2.891 V, spontaneous C)  E° cell = 2.891 V, nonspontaneous D)  E° cell = 2.891 V, spontaneous E)  None of these choices are correct." class="answers-bank-image d-inline" rel="preload" > 2H2O(l)  E° = 1.229 V
Al3+(aq)  + 3e-
   cell and indicate whether the overall reaction shown is spontaneous or nonspontaneous. O2(g)  + 4H+(aq)  + 4e-     2H2O(l)  E° = 1.229 V Al3+(aq)  + 3e-     Al(s)  E° = -1.662 V Overall reaction: 4Al(s)  + 3O2(g)  + 12H+(aq)  → 4Al3+(aq)  + 6H2O(l)  A)  E° cell = -2.891 V, nonspontaneous B)  E° cell = -2.891 V, spontaneous C)  E° cell = 2.891 V, nonspontaneous D)  E° cell = 2.891 V, spontaneous E)  None of these choices are correct." class="answers-bank-image d-inline" rel="preload" > Al(s)  E° = -1.662 V
Overall reaction:
4Al(s)  + 3O2(g)  + 12H+(aq)  → 4Al3+(aq)  + 6H2O(l)

Accepted Answer

A)   E° cell = -2.891 V, nonspontaneous
B)   E° cell = -2.891 V, spontaneous
C)   E° cell = 2.891 V, nonspontaneous
D)   E° cell = 2.891 V, spontaneous
E)   None of these choices are correct.F) None of the above
G) A) and E)

Question 13

The lead-acid battery is an example of a secondary battery.

Accepted Answer

A) True 
 B)False

Question 14

Examine the following half-reactions and select the weakest reducing agent among the substances. Cr(OH) 3(s)  + 3e-
  3(s)  + 3e-     Cr(s)  + 3OH-(aq)  E° = -1.48 V SnO2(s)  + 2H2O(l)  + 4e-     Sn(s)  + 4OH-(aq)  E° = -0.945 V MnO2(s)  + 4H+(aq)  + 2e-     Mn2+(aq)  + 2H2O(l)  E° = 1.224 V Hg2SO4(s)  + 2e-     2Hg(l)  + SO42-(aq)  E° = 0.613 V A)  Cr(s)  B)  Sn(s)  C)  Mn2+(aq)  D)  Hg(l)  E)  OH-(aq) " class="answers-bank-image d-inline" rel="preload" > Cr(s)  + 3OH-(aq)  E° = -1.48 V
SnO2(s)  + 2H2O(l)  + 4e-
  3(s)  + 3e-     Cr(s)  + 3OH-(aq)  E° = -1.48 V SnO2(s)  + 2H2O(l)  + 4e-     Sn(s)  + 4OH-(aq)  E° = -0.945 V MnO2(s)  + 4H+(aq)  + 2e-     Mn2+(aq)  + 2H2O(l)  E° = 1.224 V Hg2SO4(s)  + 2e-     2Hg(l)  + SO42-(aq)  E° = 0.613 V A)  Cr(s)  B)  Sn(s)  C)  Mn2+(aq)  D)  Hg(l)  E)  OH-(aq) " class="answers-bank-image d-inline" rel="preload" > Sn(s)  + 4OH-(aq)  E° = -0.945 V
MnO2(s)  + 4H+(aq)  + 2e-
  3(s)  + 3e-     Cr(s)  + 3OH-(aq)  E° = -1.48 V SnO2(s)  + 2H2O(l)  + 4e-     Sn(s)  + 4OH-(aq)  E° = -0.945 V MnO2(s)  + 4H+(aq)  + 2e-     Mn2+(aq)  + 2H2O(l)  E° = 1.224 V Hg2SO4(s)  + 2e-     2Hg(l)  + SO42-(aq)  E° = 0.613 V A)  Cr(s)  B)  Sn(s)  C)  Mn2+(aq)  D)  Hg(l)  E)  OH-(aq) " class="answers-bank-image d-inline" rel="preload" > Mn2+(aq)  + 2H2O(l)  E° = 1.224 V
Hg2SO4(s)  + 2e-
  3(s)  + 3e-     Cr(s)  + 3OH-(aq)  E° = -1.48 V SnO2(s)  + 2H2O(l)  + 4e-     Sn(s)  + 4OH-(aq)  E° = -0.945 V MnO2(s)  + 4H+(aq)  + 2e-     Mn2+(aq)  + 2H2O(l)  E° = 1.224 V Hg2SO4(s)  + 2e-     2Hg(l)  + SO42-(aq)  E° = 0.613 V A)  Cr(s)  B)  Sn(s)  C)  Mn2+(aq)  D)  Hg(l)  E)  OH-(aq) " class="answers-bank-image d-inline" rel="preload" > 2Hg(l)  + SO42-(aq)  E° = 0.613 V

Accepted Answer

A)   Cr(s) 
B)   Sn(s) 
C)   Mn2+(aq) 
D)   Hg(l) 
E)   OH-(aq) F) C) and D)
G) A) and B)

Question 15

Electrons are produced at the cathode of a voltaic cell.

Accepted Answer

A) True 
 B)False

Question 16

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

Accepted Answer

A)   The anode will definitely gain weight in a voltaic cell.
B)   Oxidation occurs at the cathode of both cells.
C)   The free energy change, ΔG, is negative for the voltaic cell.
D)   The electrons in the external wire flow from cathode to anode in an electrolytic cell.
E)   None of these choices are correct.F) C) and D)
G) A) and C)

Question 17

Calculate E° cell and indicate whether the overall reaction shown is spontaneous or nonspontaneous. H2O2(aq)  + 2H+(aq)  + 2e- 2H2O(l)  E° = 1.77 V
Fe3+ (aq)  + e- Fe2+(aq)  E° = 0.77 V
Overall reaction:
2Fe3+(aq)  + 2H2O(l)  → H2O2(aq)  + 2H+(aq)  + 2Fe2+(aq)

Accepted Answer

A)   E° cell = -1.00 V, nonspontaneous
B)   E° cell = -1.00 V, spontaneous
C)   E° cell = 1.00 V, nonspontaneous
D)   E° cell = 1.00 V, spontaneous
E)   E° cell = -0.23 V, nonspontaneousF) A) and E)
G) B) and D)

Question 18

A concentration cell consists of two Zn/Zn2+ electrodes. The electrolyte in compartment A is 0.10 M Zn(NO3) 2 and in compartment B is 0.60 M Zn(NO3) 2. What is the voltage of the cell at 25°C?

Accepted Answer

A)   0.010 V
B)   0.020 V
C)   0.023 V
D)   0.046 V
E)   None of these choices are correct.F) A) and D)
G) B) and D)

Question 19

How many grams of oxygen gas will be produced in the electrolysis of water, for every gram of hydrogen gas formed? Reaction: 2H2O(l)  → 2H2(g)  + O2(g)

Accepted Answer

A)   31.7 g
B)   15.9 g
C)   7.94 g
D)   3.97 g
E)   1.98 gF) A) and B)
G) A) and E)

Question 20

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) C) and D)
G) All of the above

Exam 21: Electrochemistry Chemical Change and Electrical Work

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

Correct Answer
verified

Calculate E°_cell and indicate whether the overall reaction shown is spontaneous or nonspontaneous. O₂(g) + 4H⁺(aq) + 4e^- 2H₂O(l) E° = 1.229 V Al³⁺(aq) + 3e^- Al(s) E° = -1.662 V Overall reaction: 4Al(s) + 3O₂(g) + 12H⁺(aq) → 4Al³⁺(aq) + 6H₂O(l)

Correct Answer
verified

Calculate E°_cell and indicate whether the overall reaction shown is spontaneous or nonspontaneous. H₂O₂(aq) + 2H⁺(aq) + 2e^- 2H₂O(l) E° = 1.77 V Fe³⁺ (aq) + e^- Fe²⁺(aq) E° = 0.77 V Overall reaction: 2Fe³⁺(aq) + 2H₂O(l) → H₂O₂(aq) + 2H⁺(aq) + 2Fe²⁺(aq)

Correct Answer
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What product forms at the anode during the electrolysis of molten NaBr?

Correct Answer
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Consider the reaction in the lead-acid cell Pb(s) + PbO₂(s) + 2H₂SO₄(aq) → 2PbSO₄(aq) + 2H₂O(l) For which E°_cell = 2.04 V at 298 K. ΔG° for this reaction is

Correct Answer
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When the following redox equation is balanced with smallest whole number coefficients, the coefficient for zinc will be Zn(s) + ReO₄(aq) → Re(s) + Zn₂₊(aq) (acidic solution)

Correct Answer
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A concentration cell consists of two Zn/Zn²⁺ electrodes. The electrolyte in compartment A is 0.10 M Zn(NO₃) ₂ and in compartment B is 0.60 M Zn(NO₃) ₂. What is the voltage of the cell at 25°C?

Correct Answer
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Correct Answer
verified

Which component of the following cell notation is the anode? P | || R | S

Correct Answer
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Correct Answer
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Electrons are produced at the cathode of a voltaic cell.

Correct Answer
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Which one of the following is not a redox reaction?

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 reactions occurs at the anode?

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

Correct Answer
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The value of E°_cell for the reaction 2Cr³⁺(aq) + 6Hg(l) → 2Cr(s) + 3Hg₂²⁺(aq) Is 1.59 V. Calculate ΔG° for the reaction.

Correct Answer
verified

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

Correct Answer
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How many grams of oxygen gas will be produced in the electrolysis of water, for every gram of hydrogen gas formed? Reaction: 2H₂O(l) → 2H₂(g) + O₂(g)

Correct Answer
verified

A voltaic cell consists of a Cd/Cd²⁺ electrode (E° = -0.40 V) and a Fe/Fe²⁺ electrode (E° = -0.44 V) . If E_cell = 0 and the temperature is 25°C, what is the ratio [Fe²⁺]/[Cd²⁺]?

Correct Answer
verified

The lead-acid battery is an example of a secondary battery.

Correct Answer
verified

Correct Answer
verified

Exam 21: Electrochemistry Chemical Change and Electrical Work

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

Correct AnswerverifiedShow Answer

Calculate E° cell and indicate whether the overall reaction shown is spontaneous or nonspontaneous. O2(g) + 4H+(aq) + 4e- 2H2O(l) E° = 1.229 V Al3+(aq) + 3e- Al(s) E° = -1.662 V Overall reaction: 4Al(s) + 3O2(g) + 12H+(aq) → 4Al3+(aq) + 6H2O(l)

Correct AnswerverifiedShow Answer

Calculate E° cell and indicate whether the overall reaction shown is spontaneous or nonspontaneous. H2O2(aq) + 2H+(aq) + 2e- 2H2O(l) E° = 1.77 V Fe3+ (aq) + e- Fe2+(aq) E° = 0.77 V Overall reaction: 2Fe3+(aq) + 2H2O(l) → H2O2(aq) + 2H+(aq) + 2Fe2+(aq)

Correct AnswerverifiedShow Answer

What product forms at the anode during the electrolysis of molten NaBr?

Correct AnswerverifiedShow Answer

Consider the reaction in the lead-acid cell Pb(s) + PbO2(s) + 2H2SO4(aq) → 2PbSO4(aq) + 2H2O(l) For which E° cell = 2.04 V at 298 K. ΔG° for this reaction is

Correct AnswerverifiedShow Answer

When the following redox equation is balanced with smallest whole number coefficients, the coefficient for zinc will be Zn(s) + ReO4(aq) → Re(s) + Zn2+(aq) (acidic solution)

Correct AnswerverifiedShow Answer

A concentration cell consists of two Zn/Zn2+ electrodes. The electrolyte in compartment A is 0.10 M Zn(NO3) 2 and in compartment B is 0.60 M Zn(NO3) 2. What is the voltage of the cell at 25°C?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which component of the following cell notation is the anode? P | || R | S

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Electrons are produced at the cathode of a voltaic cell.

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Which one of the following is not a redox reaction?

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 reactions occurs at the anode?

Correct AnswerverifiedShow Answer

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

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The value of E° cell for the reaction 2Cr3+(aq) + 6Hg(l) → 2Cr(s) + 3Hg22+(aq) Is 1.59 V. Calculate ΔG° for the reaction.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

How many grams of oxygen gas will be produced in the electrolysis of water, for every gram of hydrogen gas formed? Reaction: 2H2O(l) → 2H2(g) + O2(g)

Correct AnswerverifiedShow Answer

A voltaic cell consists of a Cd/Cd2+ electrode (E° = -0.40 V) and a Fe/Fe2+ electrode (E° = -0.44 V) . If Ecell = 0 and the temperature is 25°C, what is the ratio [Fe2+]/[Cd2+]?

Correct AnswerverifiedShow Answer

The lead-acid battery is an example of a secondary battery.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct Answer
verified

Calculate E°_cell and indicate whether the overall reaction shown is spontaneous or nonspontaneous. O₂(g) + 4H⁺(aq) + 4e^- 2H₂O(l) E° = 1.229 V Al³⁺(aq) + 3e^- Al(s) E° = -1.662 V Overall reaction: 4Al(s) + 3O₂(g) + 12H⁺(aq) → 4Al³⁺(aq) + 6H₂O(l)

Correct Answer
verified

Calculate E°_cell and indicate whether the overall reaction shown is spontaneous or nonspontaneous. H₂O₂(aq) + 2H⁺(aq) + 2e^- 2H₂O(l) E° = 1.77 V Fe³⁺ (aq) + e^- Fe²⁺(aq) E° = 0.77 V Overall reaction: 2Fe³⁺(aq) + 2H₂O(l) → H₂O₂(aq) + 2H⁺(aq) + 2Fe²⁺(aq)

Correct Answer
verified

Correct Answer
verified

Consider the reaction in the lead-acid cell Pb(s) + PbO₂(s) + 2H₂SO₄(aq) → 2PbSO₄(aq) + 2H₂O(l) For which E°_cell = 2.04 V at 298 K. ΔG° for this reaction is

Correct Answer
verified

When the following redox equation is balanced with smallest whole number coefficients, the coefficient for zinc will be Zn(s) + ReO₄(aq) → Re(s) + Zn₂₊(aq) (acidic solution)

Correct Answer
verified

A concentration cell consists of two Zn/Zn²⁺ electrodes. The electrolyte in compartment A is 0.10 M Zn(NO₃) ₂ and in compartment B is 0.60 M Zn(NO₃) ₂. What is the voltage of the cell at 25°C?

Correct Answer
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Correct Answer
verified

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 reactions occurs at the anode?

Correct Answer
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Correct Answer
verified

The value of E°_cell for the reaction 2Cr³⁺(aq) + 6Hg(l) → 2Cr(s) + 3Hg₂²⁺(aq) Is 1.59 V. Calculate ΔG° for the reaction.

Correct Answer
verified

Correct Answer
verified

How many grams of oxygen gas will be produced in the electrolysis of water, for every gram of hydrogen gas formed? Reaction: 2H₂O(l) → 2H₂(g) + O₂(g)

Correct Answer
verified

A voltaic cell consists of a Cd/Cd²⁺ electrode (E° = -0.40 V) and a Fe/Fe²⁺ electrode (E° = -0.44 V) . If E_cell = 0 and the temperature is 25°C, what is the ratio [Fe²⁺]/[Cd²⁺]?

Correct Answer
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Correct Answer
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Correct Answer
verified