Question 1

When the following redox equation is balanced with smallest whole number coefficients, the coefficient for the hydrogen sulfate ion will be ______. 
Al(s)  + HSO4-(aq)  + OH-(aq)   Al2O3(s)  + S2-(aq)  + H2O(l)

Accepted Answer

A)   1
B)   3
C)   4
D)   8
E)   none of the aboveF) C) and D)
G) A) and C)

Question 2

Explain what is meant by a fuel cell. Provide a balanced equation to represent the reaction in any fuel cell of your choice.

Accepted Answer

A fuel cell is a voltaic cell in which t...

Question 3

Calculate E°cell for the reaction of nickel(II)  ions with cadmium metal at 25°C. K = 1.17 × 105
 Ni2+(aq)  + Cd(s)   Cd2+(aq)  + Ni(s)

Accepted Answer

A)   0.075 V
B)   0.10 V
C)   0.12 V
D)   0.15 V
E)   0.30 VF) A) and D)
G) A) and E)

Question 4

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

Question 5

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

Accepted Answer

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

Question 6

The voltaic cell made up of cobalt, copper, and their M2+ ions, has E°cell = 0.62 V. If E° of the cathode half-cell is 0.34 V, what is E° of the anode half-cell? 
Cu2+(aq)  + Co(s)   Cu(s)  + Co2+(aq)

Accepted Answer

A)   -0.28 V
B)   -0.96 V
C)   0.28 V
D)   0.96 V
E)   none of the aboveF) B) and D)
G) B) and C)

Question 7

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 minute
E)   37.1 minutesF) C) and D)
G) B) and D)

Question 8

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, 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 B)
G) A) and C)

Question 9

In the electrolyte of an electrochemical cell, current is carried by electrons moving from the anode to the cathode.

Accepted Answer

A) True 
 B)False

Question 10

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)   Ni2+(aq)  + Al(s)   Al3+(aq)  + Ni(s) 
B)   3Ni2+(aq)  + 2Al(s)   2Al3+(aq)  + 3Ni(s) 
C)   Ni(s)  + Al3+(aq)   Ni2+(aq)  + Al(s) 
D)   3Ni(s)  + 2Al3+(aq)   3Ni2+(aq)  + 2Al(s) 
E)   none of the aboveF) A) and C)
G) A) and B)

Question 11

The value of the equilibrium constant for the reaction of nickel(II)  ions with cadmium metal is 1.17 × 105. Calculate G° for the reaction at 25°C.

Accepted Answer

A)   -12.6 kJ
B)   -28.9 kJ
C)   12.6 kJ
D)   28.9 kJ
E)   none of the aboveF) All of the above
G) B) and C)

Question 12

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)   0.041V
D)   0.028 V
E)   none of the aboveF) A) and D)
G) A) and B)

Question 13

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

Accepted Answer

A)   phosphorus from K3PO4(aq) 
B)   sodium from NaBr(aq) 
C)   aluminum from AlCl3(aq) 
D)   fluorine from KF(aq) 
E)   iodine from NaI(aq) F) A) and C)
G) D) and E)

Question 14

In the electrolysis of aqueous potassium nitrate using inert electrodes, which one of the following species is oxidized?

Accepted Answer

A)   potassium ion
B)   nitrate ion
C)   water
D)   oxygen
E)   hydronium ionF) A) and B)
G) All of the above

Question 15

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) A) and B)
G) A) and E)

Question 16

For the reaction occurring in a voltaic (galvanic) cell, F1F1F1S1F1F1F10G > 0.

Accepted Answer

A) True 
 B)False

Question 17

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. G° 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 the above.F) All of the above
G) B) and E)

Question 18

Write down equations representing the anode half-reaction, the cathode half-reaction, and the overall cell reaction for the lead-acid battery.

Accepted Answer

Anode half-reaction: Pb(s) + SO₄^2-(aq) F1F1...

Question 19

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) None of the above
G) B) and C)

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 the above statements is correct.F) All of the above
G) A) and C)

Exam 21: Electrochemistry: Chemical Change and Electrical Work

In the electrolyte of an electrochemical cell, current is carried by electrons moving from the anode to the cathode.

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The value of the equilibrium constant for the reaction of nickel(II) ions with cadmium metal is 1.17 × 105. Calculate G° for the reaction at 25°C.

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

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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

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Write down equations representing the anode half-reaction, the cathode half-reaction, and the overall cell reaction for the lead-acid battery.

Correct AnswerverifiedAnode half-reaction: Pb(s) + SO42-(aq) F1F1...View AnswerShow Answer

Calculate E°cell for the reaction of nickel(II) ions with cadmium metal at 25°C. K = 1.17 × 105 Ni2+(aq) + Cd(s)  Cd2+(aq) + Ni(s)

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When the following redox equation is balanced with smallest whole number coefficients, the coefficient for the hydrogen sulfate ion will be ______. Al(s) + HSO4-(aq) + OH-(aq)  Al2O3(s) + S2-(aq) + H2O(l)

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

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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?

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

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Which one of the following is not a redox reaction?

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Explain what is meant by a fuel cell. Provide a balanced equation to represent the reaction in any fuel cell of your choice.

Correct AnswerverifiedA fuel cell is a voltaic cell in which t...View AnswerShow Answer

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

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In the electrolysis of aqueous potassium nitrate using inert electrodes, which one of the following species is oxidized?

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

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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?

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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?

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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. G° for this reaction is

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The voltaic cell made up of cobalt, copper, and their M2+ ions, has E°cell = 0.62 V. If E° of the cathode half-cell is 0.34 V, what is E° of the anode half-cell? Cu2+(aq) + Co(s)  Cu(s) + Co2+(aq)

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For the reaction occurring in a voltaic (galvanic) cell, G > 0.

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The value of the equilibrium constant for the reaction of nickel(II) ions with cadmium metal is 1.17 × 10⁵. Calculate G°for the reaction at 25°C.

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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

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Anode half-reaction: Pb(s) + SO₄^2-(aq) F1F1...
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Calculate E°_cell for the reaction of nickel(II) ions with cadmium metal at 25°C. K = 1.17 × 10⁵ Ni²⁺(aq) + Cd(s)  Cd²⁺(aq) + Ni(s)

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When the following redox equation is balanced with smallest whole number coefficients, the coefficient for the hydrogen sulfate ion will be ______. Al(s) + HSO₄^-(aq) + OH^-(aq)  Al₂O₃(s) + S^2-(aq) + H₂O(l)

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Correct Answer
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Chromium metal is electroplated from acidic aqueous solutions containing the dichromate ion, Cr₂O₇^2-. 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?

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Correct Answer
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Correct Answer
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A fuel cell is a voltaic cell in which t...
View 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?

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

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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. G° for this reaction is

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The voltaic cell made up of cobalt, copper, and their M²⁺ ions, has E°_cell = 0.62 V. If E° of the cathode half-cell is 0.34 V, what is E° of the anode half-cell? Cu²⁺(aq) + Co(s)  Cu(s) + Co²⁺(aq)

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Correct Answer
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