Question 1

A buried iron pipe can be protected against corrosion by connecting it to a rod of copper.

Accepted Answer

A) True 
 B)False

Question 2

Two cells are connected in series, so that the same current flows through two electrodes where the following half-reactions occur Cu2+(aq)  + 2e- → Cu(s)  and Ag+(aq)  + e- → Ag(s) 
For every 1.00 g of copper produced in the first process, how many grams of silver will be
Produced in the second one?

Accepted Answer

A)   0.294 g
B)   0.588 g
C)   0.850 g
D)   1.70 g
E)   3.40 gF) A) and C)
G) A) and B)

Question 3

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, ΔG, 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) All of the above

Question 4

In the absence of oxygen, iron will rust as long as moisture is present.

Accepted Answer

A) True 
 B)False

Question 5

A concentration cell consists of two Al/Al3+electrodes. The electrolyte in compartment A is 0.050 M Al(NO3) 3 and in compartment B is 1.25 M Al(NO3) 3. What is the voltage of the cell at 25°C?

Accepted Answer

A)   0.083 V
B)   0.062 V
C)   0.041 V
D)   0.028 V
E)   None of these choices are correct.F) D) and E)
G) A) and E)

Question 6

A voltaic cell consists of an Au/Au3+ electrode (E° = 1.50 V)  and a Cu/Cu2+ electrode (E° = 0.34 V) . Calculate [Au3+] if [Cu2+] = 1.20 M and Ecell = 1.13 V at 25°C.

Accepted Answer

A)   0.001 M
B)   0.002 M
C)   0.01 M
D)   0.02 M
E)   0.04 MF) B) and C)
G) B) and D)

Question 7

Examine the following half-reactions and select the strongest oxidizing agent among the species listed. Cr2+(aq)  + 2e-
  2+(aq)  + 2e-     Cr(s)  E° = -0.913 V Fe2+(aq)  + 2e-     Fe(s)  E° = -0.447 V Sr2+(aq)  + 2e-     Sr(s)  E° = -2.89 V Co2+(aq)  + 2e-     Co(s)  E° = -0.28 V A)  Cr2+(aq)  B)  Fe(s)  C)  Fe2+(aq)  D)  Sr2+(aq)  E)  Co2+(aq) " class="answers-bank-image d-inline" rel="preload" > Cr(s)  E° = -0.913 V
Fe2+(aq)  + 2e-
  2+(aq)  + 2e-     Cr(s)  E° = -0.913 V Fe2+(aq)  + 2e-     Fe(s)  E° = -0.447 V Sr2+(aq)  + 2e-     Sr(s)  E° = -2.89 V Co2+(aq)  + 2e-     Co(s)  E° = -0.28 V A)  Cr2+(aq)  B)  Fe(s)  C)  Fe2+(aq)  D)  Sr2+(aq)  E)  Co2+(aq) " class="answers-bank-image d-inline" rel="preload" > Fe(s)  E° = -0.447 V
Sr2+(aq)  + 2e-
  2+(aq)  + 2e-     Cr(s)  E° = -0.913 V Fe2+(aq)  + 2e-     Fe(s)  E° = -0.447 V Sr2+(aq)  + 2e-     Sr(s)  E° = -2.89 V Co2+(aq)  + 2e-     Co(s)  E° = -0.28 V A)  Cr2+(aq)  B)  Fe(s)  C)  Fe2+(aq)  D)  Sr2+(aq)  E)  Co2+(aq) " class="answers-bank-image d-inline" rel="preload" > Sr(s)  E° = -2.89 V
Co2+(aq)  + 2e-
  2+(aq)  + 2e-     Cr(s)  E° = -0.913 V Fe2+(aq)  + 2e-     Fe(s)  E° = -0.447 V Sr2+(aq)  + 2e-     Sr(s)  E° = -2.89 V Co2+(aq)  + 2e-     Co(s)  E° = -0.28 V A)  Cr2+(aq)  B)  Fe(s)  C)  Fe2+(aq)  D)  Sr2+(aq)  E)  Co2+(aq) " class="answers-bank-image d-inline" rel="preload" > Co(s)  E° = -0.28 V

Accepted Answer

A)   Cr2+(aq) 
B)   Fe(s) 
C)   Fe2+(aq) 
D)   Sr2+(aq) 
E)   Co2+(aq) F) D) and E)
G) A) and B)

Question 8

Consider the reaction of iodine with manganese dioxide 3I2(s)  + 2MnO2(s)  + 8OH-(aq)  2(s)  + 2MnO2(s)  + 8OH-(aq)    6I-(aq)  + 2MnO4(aq)  + 4H2O(l)  The equilibrium constant for the overall reaction is 8.30 × 10-7. Calculate E° cell for the reaction at 25°C. A)  -0.36 V B)  -0.18 V C)  -0.12 V D)  -0.060 V E)  None of these choices are correct." class="answers-bank-image d-inline" rel="preload" > 6I-(aq)  + 2MnO4(aq)  + 4H2O(l) 
The equilibrium constant for the overall reaction is 8.30 × 10-7. Calculate E° cell for the reaction at 25°C.

Accepted Answer

A)   -0.36 V
B)   -0.18 V
C)   -0.12 V
D)   -0.060 V
E)   None of these choices are correct.F) C) and E)
G) C) and D)

Question 9

Calculate the potential of a voltaic cell (E° cell)  if it is required to do 5.43 × 10-3 kJ of work when a charge of 2.50 C is transferred.

Accepted Answer

A)   2.17 × 103 V
B)   2.17 × 10-3 V
C)   2.17 V
D)   13.6 V
E)   1.36 × 10-2 VF) A) and B)
G) A) and C)

Question 10

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)  + Zn2+(aq)  → I2(s)  + Zn(s) 
B)   I2(s)  + Zn(s)  → 2I-(aq)  + Zn2+(aq) 
C)   2I-(aq)  + Zn(s)  → I2(s)  + Zn2+(aq) 
D)   I2(s)  + Zn2+(aq)  → 2I-(aq)  + Zn(s) 
E)   None of these choices are correct.F) C) and D)
G) A) and B)

Question 11

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

Question 12

In the electrolysis of aqueous sodium sulfate at electrodes of platinum, predict the products of the cell reaction.

Accepted Answer

A)   sodium and sulfur
B)   hydrogen and sulfur
C)   oxygen and sulfur
D)   oxygen and sulfuric acid
E)   hydrogen and oxygenF) A) and C)
G) B) and D)

Question 13

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) A) and B)
G) C) and D)

Question 14

Which, if any, of the following metals would not be capable of acting as a sacrificial anode when used with iron E°Fe = -0.44 V; all E° values refer to the M2+/M half-cell reactions.

Accepted Answer

A)   manganese, Mn, E° = -1.18 V
B)   cadmium, Cd, E° = -0.40 V
C)   magnesium, Mg, E° = -2.37 V
D)   zinc, Zn, E° = -0.76 V
E)   All of these metals are capable of acting as sacrificial anodes with iron.F) A) and D)
G) A) and C)

Question 15

Which of the following types of electrochemical cell is most likely to find use in the future as a power source for electric vehicles?

Accepted Answer

A)   fuel cell
B)   nickel-metal hydride cell
C)   dry cell
D)   alkaline battery
E)   lithium-ion batteryF) All of the above
G) A) and E)

Question 16

A voltaic cell is based on the following two half-reactions: Ni+2(aq)  + 2e− → Ni(s)  E° = −0.25 V
Cr+3(aq)  + 3e- → Cr(s)  E° = -0.74 V
Sketch the cell and then select the correct statement about it.

Accepted Answer

A)   Cr serves as the cathode.
B)   The direction of electron flow through the external wire is from the Ni to the Cr electrode.
C)   Anions in solution will migrate toward the Ni+2/Ni electrode.
D)   The net cell reaction is 3Ni+2(aq)  + 2Cr(s)  → 3Ni(s)  + 2Cr+3(aq) 
E)   = 0.99 VF) C) and E)
G) A) and E)

Question 17

A primary battery is one that can be recharged.

Accepted Answer

A) True 
 B)False

Question 18

Which of the following conditions is most likely to apply to a fully-charged secondary cell?

Accepted Answer

A)   E cell l = E° cell
B)   E° cell = 0
C)    cell l = E° cell 
B)   E° cell = 0 
C)     = 1 
D)      = 1
D)    cell l = E° cell 
B)   E° cell = 0 
C)     = 1 
D)      
E)    cell l = E° cell 
B)   E° cell = 0 
C)     = 1 
D)      = KF) A) and B)
G) D) and E)

Question 19

Examine the following half-reactions and select the strongest reducing agent among the species listed. PbI2(s)  + 2e-
  2(s)  + 2e-     Pb(s)  + 2I-(aq)  E° = -0.365 V Ca2+(aq)  + 2e-     Ca(s)  E° = -2.868 V Pt2+(aq)  + 2e-     Pt(s)  E° = 1.18 V Br2(l)  + 2e-     2Br-(aq)  E° = 1.066 V A)  Pb(s)  B)  Ca(s)  C)  Pt(s)  D)  Br-(aq)  E)  Pt2+(aq) " class="answers-bank-image d-inline" rel="preload" > Pb(s)  + 2I-(aq)  E° = -0.365 V
Ca2+(aq)  + 2e-
  2(s)  + 2e-     Pb(s)  + 2I-(aq)  E° = -0.365 V Ca2+(aq)  + 2e-     Ca(s)  E° = -2.868 V Pt2+(aq)  + 2e-     Pt(s)  E° = 1.18 V Br2(l)  + 2e-     2Br-(aq)  E° = 1.066 V A)  Pb(s)  B)  Ca(s)  C)  Pt(s)  D)  Br-(aq)  E)  Pt2+(aq) " class="answers-bank-image d-inline" rel="preload" > Ca(s)  E° = -2.868 V
Pt2+(aq)  + 2e-
  2(s)  + 2e-     Pb(s)  + 2I-(aq)  E° = -0.365 V Ca2+(aq)  + 2e-     Ca(s)  E° = -2.868 V Pt2+(aq)  + 2e-     Pt(s)  E° = 1.18 V Br2(l)  + 2e-     2Br-(aq)  E° = 1.066 V A)  Pb(s)  B)  Ca(s)  C)  Pt(s)  D)  Br-(aq)  E)  Pt2+(aq) " class="answers-bank-image d-inline" rel="preload" > Pt(s)  E° = 1.18 V
Br2(l)  + 2e-
  2(s)  + 2e-     Pb(s)  + 2I-(aq)  E° = -0.365 V Ca2+(aq)  + 2e-     Ca(s)  E° = -2.868 V Pt2+(aq)  + 2e-     Pt(s)  E° = 1.18 V Br2(l)  + 2e-     2Br-(aq)  E° = 1.066 V A)  Pb(s)  B)  Ca(s)  C)  Pt(s)  D)  Br-(aq)  E)  Pt2+(aq) " class="answers-bank-image d-inline" rel="preload" > 2Br-(aq)  E° = 1.066 V

Accepted Answer

A)   Pb(s) 
B)   Ca(s) 
C)   Pt(s) 
D)   Br-(aq) 
E)   Pt2+(aq) F) C) and D)
G) C) and E)

Question 20

Consider the reaction of iodine with manganese dioxide 3I2(s)  + 2MnO2(s)  + 8OH-(aq)  2(s)  + 2MnO2(s)  + 8OH-(aq)    6I-(aq)  + 2MnO4(aq)  + 4H2O(l)  The equilibrium constant for the overall reaction is 8.30 × 10-7. Calculate ΔG° for the reaction at 25°C. A)  -15.1 kJ B)  -34.7 kJ C)  15.1 kJ D)  34.7 kJ E)  None of these choices are correct." class="answers-bank-image d-inline" rel="preload" > 6I-(aq)  + 2MnO4(aq)  + 4H2O(l) 
The equilibrium constant for the overall reaction is 8.30 × 10-7. Calculate ΔG° for the reaction at 25°C.

Accepted Answer

A)   -15.1 kJ
B)   -34.7 kJ
C)   15.1 kJ
D)   34.7 kJ
E)   None of these choices are correct.F) All of the above
G) C) and D)

Exam 21: Electrochemistry Chemical Change and Electrical Work

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

Correct Answer
verified

Which of the following types of electrochemical cell is most likely to find use in the future as a power source for electric vehicles?

Correct Answer
verified

In the absence of oxygen, iron will rust as long as moisture is present.

Correct Answer
verified

A primary battery is one that can be recharged.

Correct Answer
verified

A buried iron pipe can be protected against corrosion by connecting it to a rod of copper.

Correct Answer
verified

Calculate the potential of a voltaic cell (E°_cell) if it is required to do 5.43 × 10^-3 kJ of work when a charge of 2.50 C is transferred.

Correct Answer
verified

Which of the following conditions is most likely to apply to a fully-charged secondary cell?

Correct Answer
verified

Correct Answer
verified

Which, if any, of the following metals would not be capable of acting as a sacrificial anode when used with iron E°_Fe = -0.44 V; all E° values refer to the M²⁺/M half-cell reactions.

Correct Answer
verified

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

Correct Answer
verified

A battery that cannot be recharged is a

Correct Answer
verified

Examine the following half-reactions and select the strongest reducing agent among the species listed. PbI₂(s) + 2e_- Pb(s) + 2I^-(aq) E° = -0.365 V Ca²⁺(aq) + 2e^- Ca(s) E° = -2.868 V Pt²⁺(aq) + 2e^- Pt(s) E° = 1.18 V Br₂(l) + 2e^- 2Br^-(aq) E° = 1.066 V

Correct Answer
verified

In the electrolysis of aqueous sodium sulfate at electrodes of platinum, predict the products of the cell reaction.

Correct Answer
verified

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
verified

A voltaic cell is based on the following two half-reactions: Ni⁺²(aq) + 2e⁻ → Ni(s) E° = −0.25 V Cr⁺³(aq) + 3e^- → Cr(s) E° = -0.74 V Sketch the cell and then select the correct statement about it.

Correct Answer
verified

A concentration cell consists of two Al/Al³⁺electrodes. The electrolyte in compartment A is 0.050 M Al(NO₃) ₃ and in compartment B is 1.25 M Al(NO₃) ₃. What is the voltage of the cell at 25°C?

Correct Answer
verified

A voltaic cell consists of an Au/Au³⁺ electrode (E° = 1.50 V) and a Cu/Cu²⁺ electrode (E° = 0.34 V) . Calculate [Au³⁺] if [Cu²⁺] = 1.20 M and E_cell = 1.13 V at 25°C.

Correct Answer
verified

Consider the reaction of iodine with manganese dioxide 3I₂(s) + 2MnO₂(s) + 8OH^-(aq) 6I^-(aq) + 2MnO₄(aq) + 4H₂O(l) The equilibrium constant for the overall reaction is 8.30 × 10^-7. Calculate E°_cell for the reaction at 25°C.

Correct Answer
verified

Examine the following half-reactions and select the strongest oxidizing agent among the species listed. Cr²⁺(aq) + 2e^- Cr(s) E° = -0.913 V Fe²⁺(aq) + 2e^- Fe(s) E° = -0.447 V Sr²⁺(aq) + 2e^- Sr(s) E° = -2.89 V Co²⁺(aq) + 2e^- Co(s) E° = -0.28 V

Correct Answer
verified

Consider the reaction of iodine with manganese dioxide 3I₂(s) + 2MnO₂(s) + 8OH^-(aq) 6I^-(aq) + 2MnO₄(aq) + 4H₂O(l) The equilibrium constant for the overall reaction is 8.30 × 10^-7. Calculate ΔG° for the reaction at 25°C.

Correct Answer
verified

Exam 21: Electrochemistry Chemical Change and Electrical Work

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

Correct AnswerverifiedShow Answer

Which of the following types of electrochemical cell is most likely to find use in the future as a power source for electric vehicles?

Correct AnswerverifiedShow Answer

In the absence of oxygen, iron will rust as long as moisture is present.

Correct AnswerverifiedShow Answer

A primary battery is one that can be recharged.

Correct AnswerverifiedShow Answer

A buried iron pipe can be protected against corrosion by connecting it to a rod of copper.

Correct AnswerverifiedShow Answer

Calculate the potential of a voltaic cell (E° cell) if it is required to do 5.43 × 10-3 kJ of work when a charge of 2.50 C is transferred.

Correct AnswerverifiedShow Answer

Which of the following conditions is most likely to apply to a fully-charged secondary cell?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which, if any, of the following metals would not be capable of acting as a sacrificial anode when used with iron E°Fe = -0.44 V; all E° values refer to the M2+/M half-cell reactions.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

A battery that cannot be recharged is a

Correct AnswerverifiedShow Answer

Examine the following half-reactions and select the strongest reducing agent among the species listed. PbI2(s) + 2e- Pb(s) + 2I-(aq) E° = -0.365 V Ca2+(aq) + 2e- Ca(s) E° = -2.868 V Pt2+(aq) + 2e- Pt(s) E° = 1.18 V Br2(l) + 2e- 2Br-(aq) E° = 1.066 V

Correct AnswerverifiedShow Answer

In the electrolysis of aqueous sodium sulfate at electrodes of platinum, predict the products of the cell reaction.

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

A voltaic cell is based on the following two half-reactions: Ni+2(aq) + 2e− → Ni(s) E° = −0.25 V Cr+3(aq) + 3e- → Cr(s) E° = -0.74 V Sketch the cell and then select the correct statement about it.

Correct AnswerverifiedShow Answer

A concentration cell consists of two Al/Al3+electrodes. The electrolyte in compartment A is 0.050 M Al(NO3) 3 and in compartment B is 1.25 M Al(NO3) 3. What is the voltage of the cell at 25°C?

Correct AnswerverifiedShow Answer

A voltaic cell consists of an Au/Au3+ electrode (E° = 1.50 V) and a Cu/Cu2+ electrode (E° = 0.34 V) . Calculate [Au3+] if [Cu2+] = 1.20 M and Ecell = 1.13 V at 25°C.

Correct AnswerverifiedShow Answer

Consider the reaction of iodine with manganese dioxide 3I2(s) + 2MnO2(s) + 8OH-(aq) 6I-(aq) + 2MnO4(aq) + 4H2O(l) The equilibrium constant for the overall reaction is 8.30 × 10-7. Calculate E° cell for the reaction at 25°C.

Correct AnswerverifiedShow Answer

Examine the following half-reactions and select the strongest oxidizing agent among the species listed. Cr2+(aq) + 2e- Cr(s) E° = -0.913 V Fe2+(aq) + 2e- Fe(s) E° = -0.447 V Sr2+(aq) + 2e- Sr(s) E° = -2.89 V Co2+(aq) + 2e- Co(s) E° = -0.28 V

Correct AnswerverifiedShow Answer

Consider the reaction of iodine with manganese dioxide 3I2(s) + 2MnO2(s) + 8OH-(aq) 6I-(aq) + 2MnO4(aq) + 4H2O(l) The equilibrium constant for the overall reaction is 8.30 × 10-7. Calculate ΔG° for the reaction at 25°C.

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Calculate the potential of a voltaic cell (E°_cell) if it is required to do 5.43 × 10^-3 kJ of work when a charge of 2.50 C is transferred.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Which, if any, of the following metals would not be capable of acting as a sacrificial anode when used with iron E°_Fe = -0.44 V; all E° values refer to the M²⁺/M half-cell reactions.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Examine the following half-reactions and select the strongest reducing agent among the species listed. PbI₂(s) + 2e_- Pb(s) + 2I^-(aq) E° = -0.365 V Ca²⁺(aq) + 2e^- Ca(s) E° = -2.868 V Pt²⁺(aq) + 2e^- Pt(s) E° = 1.18 V Br₂(l) + 2e^- 2Br^-(aq) E° = 1.066 V

Correct Answer
verified

Correct Answer
verified

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
verified

A voltaic cell is based on the following two half-reactions: Ni⁺²(aq) + 2e⁻ → Ni(s) E° = −0.25 V Cr⁺³(aq) + 3e^- → Cr(s) E° = -0.74 V Sketch the cell and then select the correct statement about it.

Correct Answer
verified

A concentration cell consists of two Al/Al³⁺electrodes. The electrolyte in compartment A is 0.050 M Al(NO₃) ₃ and in compartment B is 1.25 M Al(NO₃) ₃. What is the voltage of the cell at 25°C?

Correct Answer
verified

A voltaic cell consists of an Au/Au³⁺ electrode (E° = 1.50 V) and a Cu/Cu²⁺ electrode (E° = 0.34 V) . Calculate [Au³⁺] if [Cu²⁺] = 1.20 M and E_cell = 1.13 V at 25°C.

Correct Answer
verified

Consider the reaction of iodine with manganese dioxide 3I₂(s) + 2MnO₂(s) + 8OH^-(aq) 6I^-(aq) + 2MnO₄(aq) + 4H₂O(l) The equilibrium constant for the overall reaction is 8.30 × 10^-7. Calculate E°_cell for the reaction at 25°C.

Correct Answer
verified

Examine the following half-reactions and select the strongest oxidizing agent among the species listed. Cr²⁺(aq) + 2e^- Cr(s) E° = -0.913 V Fe²⁺(aq) + 2e^- Fe(s) E° = -0.447 V Sr²⁺(aq) + 2e^- Sr(s) E° = -2.89 V Co²⁺(aq) + 2e^- Co(s) E° = -0.28 V

Correct Answer
verified

Consider the reaction of iodine with manganese dioxide 3I₂(s) + 2MnO₂(s) + 8OH^-(aq) 6I^-(aq) + 2MnO₄(aq) + 4H₂O(l) The equilibrium constant for the overall reaction is 8.30 × 10^-7. Calculate ΔG° for the reaction at 25°C.

Correct Answer
verified