Question 1

Silver tarnish (Ag2S)  can be removed by immersing silverware in a hot solution of baking soda (NaHCO3)  in a pan lined with aluminum foil; however, foul-smelling hydrogen sulfide gas (H2S)  is produced.Which one of the following reactions does NOT represent part or all of what is happening? 2S)  can be removed by immersing silverware in a hot solution of baking soda (NaHCO3)  in a pan lined with aluminum foil; however, foul-smelling hydrogen sulfide gas (H2S)  is produced.Which one of the following reactions does NOT represent part or all of what is happening?   A) Al  \rightarrow Al3++10 3e- B) Ag++e- \rightarrow  Ag C) 2 HCO - +S2 -  \rightarrow  H S +2 CO 2 - 3 2 3 D) 3Ag2S+ 2 Al+ 3 H2O  \rightarrow  6 Ag +AL2O3 + 3 H2S E) 2 HCO3-+Ag2S  \rightarrow  H2S+ 2 CO32- + 2 Ag " class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  Al  →\rightarrow→ Al3++10 3e-
B)  Ag++e- →\rightarrow→  Ag
C)  2 HCO - +S2 -  →\rightarrow→  H S +2 CO 2 - 3 2 3
D)  3Ag2S+ 2 Al+ 3 H2O  →\rightarrow→  6 Ag +AL2O3 + 3 H2S
E)  2 HCO3-+Ag2S  →\rightarrow→  H2S+ 2 CO32- + 2 Ag F) A) and D)
G) B) and D)

Question 2

Which statement below regarding the polarities and electrode assignments in voltaic and electrolytic cells is true?

Accepted Answer

A)  The anode and cathode remain the same regardless of whether the cell is voltaic or electrolytic; the difference is that the former releases energy and the latter consumes energy.
B)  Electrons flow from the cathode to the anode in a voltaic cell; the electron flow is reversed in an electrolytic cell.
C)  In a voltaic cell, the anode is positive and the cathode is negative; the opposite is true in an electrolytic cell (anode -; cathode +) .
D)  In a voltaic cell, the anode is negative and the cathode is positive; the opposite is true in an electrolytic cell (anode -; cathode +) .
E)  In both types of cells, the anode is positive and the cathode is negative because oxidation happens at the anode and reduction happens at the cathode.F) B) and E)
G) A) and B)

Question 3

A voltaic cell is constructed based on the reaction of Ag(CN) 2-(aq)  with Cr(s)  producing Ag(s)  and Cr3+(s) .Identify the correct cell diagram.

Accepted Answer

A)  Ag(CN) 2-(aq)  | Cr(s)  || Ag(s)  | Cr3+(aq) 
B)  Ag(s)  | Cr3+(aq)  || Ag(CN) 2-(aq)  | Cr(s) 
C)  Cr(s)  | Cr3+(aq)  || Ag(s)  | Ag(CN) 2-(aq) 
D)  Ag(CN) 2-(aq)  | Ag(s)  || Cr(s)  | Cr3+(aq) 
E)  Cr(s)  | Cr3+(aq)  || Ag(CN) 2-(aq)  | Ag(s) F) All of the above
G) B) and C)

Question 4

An electrochemical cell has both a silver anode and a silver cathode.The solutions of silver nitrate in contact with the electrodes have different concentrations.Which statement(s)  correctly describe(s)  this cell? 
I.The cell potential is 0.
II.The cell potential is negative.
III.The cell potential is positive.
IV.No electrons will flow through the external circuit.

Accepted Answer

A)  I only
B)  II only
C)  III only
D)  I and IV
E)  II and IVF) All of the above
G) A) and D)

Question 5

An electrochemical cell contains a standard hydrogen electrode and a cathode consisting of a metallic chromium electrode, Cr(s) , in contact with a 1.00 M chromium solution, Cr3+(aq) .The voltage produced by this cell was measured at 25°C.Which statements describe the results of this measurement, assuming the conditions are ideal? The cell voltage with the appropriate sign equals I.the cell potential.
II.the electromotive force.
III.the standard cell potential.
IV.the standard reduction potential for Cr3+/Cr.

Accepted Answer

A)  I only
B)  I and II
C)  I, II, and III
D)  I, II, III, and IV
E)  III onlyF) C) and D)
G) A) and C)

Question 6

Which statement below about a voltaic cell is FALSE?

Accepted Answer

A)  Usually the cathode is a metal strip.
B)  Reduction occurs at the cathode.
C)  Electrons are produced at the cathode.
D)  In the external circuit, electrons flow toward the cathode.
E)  Chemical species can have their oxidation number decreased at the cathode.F) B) and E)
G) None of the above

Question 7

Using the following data, determine the standard cell potential Eo cell for the electrochemical cell constructed using the following reaction: Mn(s)  + Cd2+(aq)   →\rightarrow→ Mn2+(aq)  + Cd(s) . 
o cell for the electrochemical cell constructed using the following reaction: Mn(s)  + Cd2+(aq)   \rightarrow Mn2+(aq)  + Cd(s) .    A) (+.782 V)  B) (-0.782 V)  C) (+1.967 V)  D) (-1.588 V)  E) (+1.588 V)  " class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  (+.782 V) 
B)  (-0.782 V) 
C)  (+1.967 V) 
D)  (-1.588 V) 
E)  (+1.588 V)  F) C) and E)
G) B) and E)

Question 8

The unit of electrical power, watt (W) , is defined as

Accepted Answer

A)  1 C.
B)  1 V.
C)  1 J.
D)  1 C V.
E)  1 J/s.F) C) and D)
G) All of the above

Question 9

A single cell in a lead acid battery produces 2.0 V and is constructed based on a chemical process that involves the transfer of 2 electrons from anode to cathode per reaction.What is the change in free energy?

Accepted Answer

-3.9* 10<s...

Question 10

A concentration cell with a cell potential of +0.4759 V at 298 K is made using silver electrodes and aqueous silver ion solutions at 298 K.In one compartment, the Ag+ concentration is 1.000 M.In the other compartment, the Ag+ concentration is due to the dissolution of slightly soluble AgI.Calculate the concentration of the Ag+ in the saturated AgI solution.

Accepted Answer

A)  8.36 *10-17 M
B)  0.0282 M
C)  0.940 M
D)  9.14 * 10-9 M
E)  More information is needed.F) C) and E)
G) A) and B)

Question 11

An electrochemical cell is constructed with a zinc metal anode in contact with a 0.052 M solution of zinc nitrate and a silver cathode in contact with a 0.0042 M solution of silver(I)  nitrate.What is the value of Q to use in the Nernst equation for this cell?

Accepted Answer

A)  2.9 * 103
B)  12
C)  8.1* 10-2
D)  3.4 * 10-4
E)  1.00F) A) and B)
G) A) and C)

Question 12

Using the following data, determine the standard cell potential Eo cell for the electrochemical cell constructed based on the following unbalanced reaction expression: 
o cell for the electrochemical cell constructed based on the following unbalanced reaction expression:       A) (-1.385 V)  B) (+1.385 V)  C) (+1.939 V)  D) (-2.770 V)  E) (+2.770 V) " class="answers-bank-image d-inline" rel="preload" >

o cell for the electrochemical cell constructed based on the following unbalanced reaction expression:       A) (-1.385 V)  B) (+1.385 V)  C) (+1.939 V)  D) (-2.770 V)  E) (+2.770 V) " class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  (-1.385 V) 
B)  (+1.385 V) 
C)  (+1.939 V) 
D)  (-2.770 V) 
E)  (+2.770 V) F) A) and B)
G) B) and D)

Question 13

The charge supplied by a battery can be determined by

Accepted Answer

A)  multiplying amperes by seconds.
B)  dividing amperes by seconds.
C)  multiplying coulombs by volts.
D)  multiplying coulombs by seconds.
E)  dividing coulombs by seconds.F) B) and E)
G) B) and C)

Question 14

Which one of the following is NOT an advantage of lithium batteries?

Accepted Answer

A)  the extremely negative standard reduction potential of lithium
B)  the small molar mass of lithium
C)  the high mobility of lithium in solids
D)  the small cell potentials produced by these batteries
E)  a high battery capacityF) A) and E)
G) C) and D)

Question 15

Which statement below regarding the recharging of a battery is FALSE?

Accepted Answer

A)  Electrical energy is used to drive the redox reaction in the nonspontaneous direction.
B)  The cathode is the positive terminal and the anode is the negative terminal.
C)  An external source of electrical energy does work on the chemical system in the battery.
D)  As the battery is recharged, higher energy products are formed from lower energy reactants.
E)  When the battery is recharging, the current flow is in the opposite direction as when the battery is discharging.F) A) and E)
G) C) and D)

Question 16

An electronic device requires four 1.50-V AA alkaline batteries, which, connected in series, give 6.00 V.If the cell transfers two moles of electrons for each mole of reaction, what is the Gibbs free-energy change for the redox reaction in each of the batteries?

Accepted Answer

A)  (-1.45 *102 kJ) 
B)  (+1.45 * 102 kJ) 
C)  (+5.79 *102 kJ) 
D)  (-8.69* 102 kJ) 
E)  (-2.90 * 102 kJ) F) A) and C)
G) C) and D)

Question 17

A concentration cell is constructed by using the same half-reaction for both the cathode and anode.What is the value of standard cell potential, E°, for a concentration cell that combines a silver anode in contact with 0.10 M silver nitrate and a silver cathode in contact with 3.0*10-5 M silver nitrate? 
(E° =0.80 V for Ag /Ag +)

Accepted Answer

A)  (-0.21 V) 
B)  0.00 V
C)  0.80V
D)  (-0.80 V) 
E)  (+0.21 V) F) B) and C)
G) A) and D)

Question 18

The spontaneous redox reaction in a voltaic cell has

Accepted Answer

A)  Eo cell  o cell    0,   \Delta  G°    0, and K     1  
B)  Eocell      0,   \Delta  G°     0, and K     1  
C)  Eo cell     0,   \Delta  G°     0, and K    1  
D)  Eo cell    0,  (\Delta\)  G°     0, and K     1  
E)  Eocell     0,   \Delta   G° = 0, and K     1  " class="answers-bank-image d-inline" rel="preload" > 0,   Δ\DeltaΔ  G°   0, and K    1 
B)  Eocell     0,   Δ\DeltaΔ  G°    0, and K    1 
C)  Eo cell    0,   Δ\DeltaΔ  G°    0, and K   1 
D)  Eo cell   0,  (\Delta\)  G°    0, and K    1 
E)  Eocell    0,   Δ\DeltaΔ   G° = 0, and K    1  F) B) and D)
G) A) and D)

Question 19

The following reaction is called the "super iron reaction." In this reaction, identify 
1) the reducing agent, 
2) the oxidizing agent, and 
3) the number of electrons transferred for the reaction as written, and 
4) explain why it is called the "super iron reaction."
2 K2 FeO4 (aq) +3 Zn(s) $\rightarrow$  Fe2 O3 (s) +ZnO(s) + 2 K2 ZnO2 (aq)

Accepted Answer

1) Zinc metal is oxidized to Zn(II), so ...

Question 20

The change in free energy for a reaction,  Δ\DeltaΔ G, depends on the stoichiometric coefficients used in writing the reaction, but cell potentials, E, do not depend on these coefficients.Which statement accounts for this difference?

Accepted Answer

A)  These quantities  Δ\DeltaΔ G and 
E)   are not related, so this difference is not an issue.
B)  The free-energy change is defined for general reactions, and the electromotive force is defined for electrochemical reactions, so this difference is not an issue.
C)  The difference is not relevant because the units differ: kJ/mol for  Δ\DeltaΔ G, and V for E.
D)  The change in free energy depends on both the reaction and the amount of material reacting, while the cell potential depends only on the reaction.
E)  The statement is false. Δ\DeltaΔ G does not depend on the stoichiometric coefficients. F) A) and D)
G) C) and D)

Exam 17: Electrochemistry the Quest for Clean Energy

A voltaic cell is constructed based on the reaction of Ag(CN) ₂^-(aq) with Cr(s) producing Ag(s) and Cr³⁺(s) .Identify the correct cell diagram.

Correct Answer
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Using the following data, determine the standard cell potential E^o_cellfor the electrochemical cell constructed based on the following unbalanced reaction expression:

Correct Answer
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The unit of electrical power, watt (W) , is defined as

Correct Answer
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Correct Answer
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An electronic device requires four 1.50-V AA alkaline batteries, which, connected in series, give 6.00 V.If the cell transfers two moles of electrons for each mole of reaction, what is the Gibbs free-energy change for the redox reaction in each of the batteries?

Correct Answer
verified

Correct Answer
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Which one of the following is NOT an advantage of lithium batteries?

Correct Answer
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A single cell in a lead acid battery produces 2.0 V and is constructed based on a chemical process that involves the transfer of 2 electrons from anode to cathode per reaction.What is the change in free energy?

Correct Answer
verified
-3.9* 10
View Answer

Correct Answer
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The charge supplied by a battery can be determined by

Correct Answer
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Which statement below about a voltaic cell is FALSE?

Correct Answer
verified

Correct Answer
verified

Which statement below regarding the recharging of a battery is FALSE?

Correct Answer
verified

The spontaneous redox reaction in a voltaic cell has

Correct Answer
verified

The change in free energy for a reaction, $\Delta$ G, depends on the stoichiometric coefficients used in writing the reaction, but cell potentials, E, do not depend on these coefficients.Which statement accounts for this difference?

Correct Answer
verified

Correct Answer
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Which statement below regarding the polarities and electrode assignments in voltaic and electrolytic cells is true?

Correct Answer
verified

Correct Answer
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1) Zinc metal is oxidized to Zn(II), so ...
View Answer

Correct Answer
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An electrochemical cell is constructed with a zinc metal anode in contact with a 0.052 M solution of zinc nitrate and a silver cathode in contact with a 0.0042 M solution of silver(I) nitrate.What is the value of Q to use in the Nernst equation for this cell?

Correct Answer
verified

Exam 17: Electrochemistry the Quest for Clean Energy

A voltaic cell is constructed based on the reaction of Ag(CN) 2-(aq) with Cr(s) producing Ag(s) and Cr3+(s) .Identify the correct cell diagram.

Correct AnswerverifiedShow Answer

Using the following data, determine the standard cell potential Eo cell for the electrochemical cell constructed based on the following unbalanced reaction expression:

Correct AnswerverifiedShow Answer

The unit of electrical power, watt (W) , is defined as

Correct AnswerverifiedShow Answer

Silver tarnish (Ag2S) can be removed by immersing silverware in a hot solution of baking soda (NaHCO3) in a pan lined with aluminum foil; however, foul-smelling hydrogen sulfide gas (H2S) is produced.Which one of the following reactions does NOT represent part or all of what is happening?

Correct AnswerverifiedShow Answer

An electronic device requires four 1.50-V AA alkaline batteries, which, connected in series, give 6.00 V.If the cell transfers two moles of electrons for each mole of reaction, what is the Gibbs free-energy change for the redox reaction in each of the batteries?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which one of the following is NOT an advantage of lithium batteries?

Correct AnswerverifiedShow Answer

A single cell in a lead acid battery produces 2.0 V and is constructed based on a chemical process that involves the transfer of 2 electrons from anode to cathode per reaction.What is the change in free energy?

Correct Answerverified-3.9* 10View AnswerShow Answer

Correct AnswerverifiedShow Answer

The charge supplied by a battery can be determined by

Correct AnswerverifiedShow Answer

Which statement below about a voltaic cell is FALSE?

Correct AnswerverifiedShow Answer

Using the following data, determine the standard cell potential Eo cell for the electrochemical cell constructed using the following reaction: Mn(s) + Cd2+(aq) →\rightarrow→ Mn2+(aq) + Cd(s) .

Correct AnswerverifiedShow Answer

Which statement below regarding the recharging of a battery is FALSE?

Correct AnswerverifiedShow Answer

The spontaneous redox reaction in a voltaic cell has

Correct AnswerverifiedShow Answer

The change in free energy for a reaction, Δ\DeltaΔ G, depends on the stoichiometric coefficients used in writing the reaction, but cell potentials, E, do not depend on these coefficients.Which statement accounts for this difference?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which statement below regarding the polarities and electrode assignments in voltaic and electrolytic cells is true?

Correct AnswerverifiedShow Answer

Correct Answerverified1) Zinc metal is oxidized to Zn(II), so ...View AnswerShow Answer

Correct AnswerverifiedShow Answer

An electrochemical cell is constructed with a zinc metal anode in contact with a 0.052 M solution of zinc nitrate and a silver cathode in contact with a 0.0042 M solution of silver(I) nitrate.What is the value of Q to use in the Nernst equation for this cell?

Correct AnswerverifiedShow Answer

A voltaic cell is constructed based on the reaction of Ag(CN) ₂^-(aq) with Cr(s) producing Ag(s) and Cr³⁺(s) .Identify the correct cell diagram.

Correct Answer
verified

Using the following data, determine the standard cell potential E^o_cellfor the electrochemical cell constructed based on the following unbalanced reaction expression:

Correct Answer
verified

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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Correct Answer
verified
-3.9* 10
View Answer

Correct Answer
verified

Correct Answer
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Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

The change in free energy for a reaction, $\Delta$ G, depends on the stoichiometric coefficients used in writing the reaction, but cell potentials, E, do not depend on these coefficients.Which statement accounts for this difference?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
1) Zinc metal is oxidized to Zn(II), so ...
View Answer

Correct Answer
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Correct Answer
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