Question 1

A voltaic cell is one in which

Accepted Answer

A)  the standard reduction potentials of the two half-cell reactions are equal to one another 
B)  the standard cell voltage is positive 
C)  the standard cell voltage is negative 
D)  both a and b are correct 
E)  both a and c are correct 
A)  the standard reduction potentials of the two half-cell reactions are equal to one another 
B)  the standard cell voltage is positive 
C)  the standard cell voltage is negative 
D)  both a and b are correct 
E)  both a and c are correct B

Question 2

Which is not true of the standard conditions for electrochemical cell measurements?

Accepted Answer

A)  the cell voltage is always positive 
B)  solutes are at 1.0 M concentration 
C)  solids are in the pure state 
D)  liquids are in the pure state 
E)  gases are at 1 bar pressure 
A)  the cell voltage is always positive 
B)  solutes are at 1.0 M concentration 
C)  solids are in the pure state 
D)  liquids are in the pure state 
E)  gases are at 1 bar pressure A

Question 3

A mass of 0.839 g of a divalent metal is plated out of a solution of the divalent metal ion. This takes 67.2 min at a current of 0.63 A. What is the metal? (Hint: find its atomic mass.)

Accepted Answer

A)  Cd 
B)  Cu 
C)  Hg 
D)  Fe 
E)  Mg 
A)  Cd 
B)  Cu 
C)  Hg 
D)  Fe 
E)  Mg B

Question 4

Exhibit 18-2 Use this list of half-reactions to answer the following question(s).
 
Refer to Exhibit 18-2. How many different cells with E$\circ$cell in excess of +1.90 V can be constructed using the half-reactions given in the table?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5 
A)  1 
B)  2 
C)  3 
D)  4 
E)  5

Question 5

Answer the following questions:
a. Briefly explain why aluminum is usually isolated from its ore by electrolysis, not by chemical reduction.
b. Explain why this electrolysis has to be performed on a molten aluminum salt, not in aqueous solution.

Accepted Answer

a. Aluminum has a large negative reducti

Question 6

Which statement concerning the number of electrons involved in electrolysis is not correct?

Accepted Answer

A)  The total charge is obtained by multiplying the current in amps by the time in seconds. 
B)  The charge associated with one mole of electrons is called the Faraday. 
C)  In producing one mole of Cl2(g) from Cl-(aq), one mole of electrons is produced. 
D)  When one mole of Fe(s) is produced from Fe3+(aq), three moles of electrons are needed. 
E)  Electroplating of one mole of silver from a solution of silver ions requires one mole of electrons. 
A)  The total charge is obtained by multiplying the current in amps by the time in seconds. 
B)  The charge associated with one mole of electrons is called the Faraday. 
C)  In producing one mole of Cl2(g) from Cl-(aq), one mole of electrons is produced. 
D)  When one mole of Fe(s) is produced from Fe3+(aq), three moles of electrons are needed. 
E)  Electroplating of one mole of silver from a solution of silver ions requires one mole of electrons.

Question 7

Explain why galvanizing steel chain-link fencing is a more effective strategy to prevent corrosion than simply painting it.

Accepted Answer

Both painting and galvanizing (coating w

Question 8

Exhibit 18-2 Use this list of half-reactions to answer the following question(s).
  Refer to Exhibit 18-2. The strongest oxidizing agent in the table is

Accepted Answer

A)  Al(s) 
B)  Al3+(aq) 
C)  H+(aq) 
D)  MnO4-(aq) 
E)  Mn2+(aq) 
A)  Al(s) 
B)  Al3+(aq) 
C)  H+(aq) 
D)  MnO4-(aq) 
E)  Mn2+(aq)

Question 9

Select the material containing the element with the highest oxidation number and determine how many electrons are required to reduce that element to an oxidation number of zero.

Accepted Answer

A)  8 
B)  7 
C)  6 
D)  4 
E)  3 
A)  8 
B)  7 
C)  6 
D)  4 
E)  3

Question 10

Which process could not be an electrolytic reaction?

Accepted Answer

A)  2 H2O(l) 2 H2(g) + O2(g) 
B)  2 Al2O3(l) 4 Al(l) + 3 O2(g) 
C)  Na+(aq) + Cl-(aq) 2 Na(l) + Cl2(g) 
D)  2 Fe(s) + 3 O2(g) Fe2O3(s) 
E)  2 PbSO4(s) + 4 H2O(l) Pb(s) + PbO2(s) + 2 H2SO4(aq) 
A)  2 H2O(l) 2 H2(g) + O2(g) 
B)  2 Al2O3(l) 4 Al(l) + 3 O2(g) 
C)  Na+(aq) + Cl-(aq) 2 Na(l) + Cl2(g) 
D)  2 Fe(s) + 3 O2(g) Fe2O3(s) 
E)  2 PbSO4(s) + 4 H2O(l) Pb(s) + PbO2(s) + 2 H2SO4(aq)

Question 11

Which of these components must be present in a redox reaction?

Accepted Answer

A)  a substance present as an element which becomes incorporated into a molecule, or vice versa 
B)  an atom whose oxidation number increases 
C)  an atom whose oxidation number decreases 
D)  either b or c 
E)  both b and c 
A)  a substance present as an element which becomes incorporated into a molecule, or vice versa 
B)  an atom whose oxidation number increases 
C)  an atom whose oxidation number decreases 
D)  either b or c 
E)  both b and c

Question 12

An underground steel fuel pipe buried in an area that is infiltrated by sea water could be protected against corrosion by using

Accepted Answer

A)  anodic inhibition 
B)  cathodic protection 
C)  both anodic inhibition and cathodic protection 
D)  any of these methods would be effective 
E)  none of these methods would be effective 
A)  anodic inhibition 
B)  cathodic protection 
C)  both anodic inhibition and cathodic protection 
D)  any of these methods would be effective 
E)  none of these methods would be effective

Question 13

The value of E$\circ$cell for the cell shown below is + 1.41 V.  
 What is the value of Ecell at 25$\circ$C if the concentration of Al3+(aq) is 0.050 M, and of Ni2+(aq), 2.0 M?

Accepted Answer

A)  +1.34 V 
B)  +1.38 V 
C)  +1.41 V 
D)  +1.44 V 
E)  +1.48 V 
A)  +1.34 V 
B)  +1.38 V 
C)  +1.41 V 
D)  +1.44 V 
E)  +1.48 V

Question 14

Which statement is correct?

Accepted Answer

A)  all electrolytic cells are voltaic cells 
B)  all voltaic cells are electrolytic cells 
C)  metals corrode by an electrolytic process 
D)  voltaic cells and electrolytic cells are both electrochemical cells 
E)  all electrochemical cells are electrolytic cells 
A)  all electrolytic cells are voltaic cells 
B)  all voltaic cells are electrolytic cells 
C)  metals corrode by an electrolytic process 
D)  voltaic cells and electrolytic cells are both electrochemical cells 
E)  all electrochemical cells are electrolytic cells

Question 15

The value of Ecell at 25$\circ$C for the cell shown below is +1.27 V. What is the value of E$\circ$cell?

Accepted Answer

A)  1.57 V 
B)  1.28 V 
C)  1.26 V 
D)  1.23 V 
E)  0.97 V 
A)  1.57 V 
B)  1.28 V 
C)  1.26 V 
D)  1.23 V 
E)  0.97 V

Question 16

Refer to the following values of standard reduction potentials.
   a. Write the balanced overall reaction for gold reacting with zinc(II) ion.
b. Calculate the value of E°cell for the reaction.
c. How many electrons are transferred in this reaction? Explain.
d. Calculate the value of DG° for this cell at 25°C.
e. Is this reaction product-favored or reactant-favored? Explain how your answers in Parts b, d, and e support this conclusion.

Accepted Answer

a. 3 Zn²+(aq) + 2 Au(s) ® 3 Zn(s) + 2 Au³+

Question 17

Which statement concerning the proton exchange membrane fuel cell is not correct?

Accepted Answer

A)  At the anode, hydrogen gas is reduced to form water. 
B)  At the cathode, oxygen is reduced to water. 
C)  The cell uses platinum as a catalyst. 
D)  The actual fuel cell reaction causes no pollution of any kind. 
E)  A limiting factor is the cost of producing hydrogen as the fuel. 
A)  At the anode, hydrogen gas is reduced to form water. 
B)  At the cathode, oxygen is reduced to water. 
C)  The cell uses platinum as a catalyst. 
D)  The actual fuel cell reaction causes no pollution of any kind. 
E)  A limiting factor is the cost of producing hydrogen as the fuel.

Question 18

Which change does not indicate a reduction?

Accepted Answer

A)  decrease in oxidation number 
B)  gain of electrons 
C)  electrons as reactants 
D)  reactant acting as a reducing agent 
E)  pure oxygen becoming oxide ion 
A)  decrease in oxidation number 
B)  gain of electrons 
C)  electrons as reactants 
D)  reactant acting as a reducing agent 
E)  pure oxygen becoming oxide ion

Question 19

In the salt bridge in an electrochemical cell,

Accepted Answer

A)  negatively charged ions migrate towards the anode compartment 
B)  positively charged ions migrate towards the anode compartment 
C)  negatively charged ions migrate towards the cathode compartment 
D)  both b and c 
E)  neither a nor c 
A)  negatively charged ions migrate towards the anode compartment 
B)  positively charged ions migrate towards the anode compartment 
C)  negatively charged ions migrate towards the cathode compartment 
D)  both b and c 
E)  neither a nor c

Question 20

If cadmium metal and the Fe(III) ion are mixed in aqueous solution, a solution containing Cd(II) and Fe(II) results. The balanced equation for this process is

Accepted Answer

A)  Cd(s) + Fe3+(aq) Fe2+(aq) + Cd2+(aq) 
B)  Cd(s) + 2 Fe3+(aq) 2 Fe2+(aq) + Cd2+(aq) 
C)  2 Cd(s) + Fe3+(aq) Fe2+(aq) + 2 Cd2+(aq) 
D)  2 Cd(s) + Fe3+(aq) 2 Fe2+(aq) + Cd2+(aq) 
A)  Cd(s) + Fe3+(aq) Fe2+(aq) + Cd2+(aq) 
B)  Cd(s) + 2 Fe3+(aq) 2 Fe2+(aq) + Cd2+(aq) 
C)  2 Cd(s) + Fe3+(aq) Fe2+(aq) + 2 Cd2+(aq) 
D)  2 Cd(s) + Fe3+(aq) 2 Fe2+(aq) + Cd2+(aq)

A voltaic cell is one in which

Which is not true of the standard conditions for electrochemical cell measurements?

A mass of 0.839 g of a divalent metal is plated out of a solution of the divalent metal ion. This takes 67.2 min at a current of 0.63 A. What is the metal? (Hint: find its atomic mass.)

Answer the following questions: a. Briefly explain why aluminum is usually isolated from its ore by electrolysis, not by chemical reduction. b. Explain why this electrolysis has to be performed on a molten aluminum salt, not in aqueous solution.

Which statement concerning the number of electrons involved in electrolysis is not correct?

Explain why galvanizing steel chain-link fencing is a more effective strategy to prevent corrosion than simply painting it.

Exhibit 18-2 Use this list of half-reactions to answer the following question(s). Refer to Exhibit 18-2. The strongest oxidizing agent in the table is

Select the material containing the element with the highest oxidation number and determine how many electrons are required to reduce that element to an oxidation number of zero.

Which process could not be an electrolytic reaction?

Which of these components must be present in a redox reaction?

An underground steel fuel pipe buried in an area that is infiltrated by sea water could be protected against corrosion by using

Which statement is correct?

The value of E_cell at 25^$\circ$C for the cell shown below is +1.27 V. What is the value of E^$\circ$_cell? $The value of E<sub>cell</sub> at 25<sup> \circ </sup>C for the cell shown below is +1.27 V. What is the value of E<sup> \circ </sup><sub>cell</sub>?$

Which statement concerning the proton exchange membrane fuel cell is not correct?

Which change does not indicate a reduction?

In the salt bridge in an electrochemical cell,

If cadmium metal and the Fe(III) ion are mixed in aqueous solution, a solution containing Cd(II) and Fe(II) results. The balanced equation for this process is

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Exam 18: Electrochemistry and Its Applications

A voltaic cell is one in which

Which is not true of the standard conditions for electrochemical cell measurements?

A mass of 0.839 g of a divalent metal is plated out of a solution of the divalent metal ion. This takes 67.2 min at a current of 0.63 A. What is the metal? (Hint: find its atomic mass.)

Exhibit 18-2 Use this list of half-reactions to answer the following question(s). Refer to Exhibit 18-2. How many different cells with E ∘\circ∘ cell in excess of +1.90 V can be constructed using the half-reactions given in the table?

Answer the following questions: a. Briefly explain why aluminum is usually isolated from its ore by electrolysis, not by chemical reduction. b. Explain why this electrolysis has to be performed on a molten aluminum salt, not in aqueous solution.

Which statement concerning the number of electrons involved in electrolysis is not correct?

Explain why galvanizing steel chain-link fencing is a more effective strategy to prevent corrosion than simply painting it.

Exhibit 18-2 Use this list of half-reactions to answer the following question(s). Refer to Exhibit 18-2. The strongest oxidizing agent in the table is

Select the material containing the element with the highest oxidation number and determine how many electrons are required to reduce that element to an oxidation number of zero.

Which process could not be an electrolytic reaction?

Which of these components must be present in a redox reaction?

An underground steel fuel pipe buried in an area that is infiltrated by sea water could be protected against corrosion by using

The value of E ∘\circ∘ cell for the cell shown below is + 1.41 V. What is the value of Ecell at 25 ∘\circ∘ C if the concentration of Al3+(aq) is 0.050 M, and of Ni2+(aq), 2.0 M?

Which statement is correct?

The value of Ecell at 25 ∘\circ∘ C for the cell shown below is +1.27 V. What is the value of E ∘\circ∘ cell?

Which statement concerning the proton exchange membrane fuel cell is not correct?

Which change does not indicate a reduction?

In the salt bridge in an electrochemical cell,

If cadmium metal and the Fe(III) ion are mixed in aqueous solution, a solution containing Cd(II) and Fe(II) results. The balanced equation for this process is

The Nature of Chemistry

Atoms and Elements

Chemical Compounds

Quantities of Reactants and Products

Chemical Reactions

Energy and Chemical Reactions

Electron Configurations and the Periodic Table

Covalent Bonding

Molecular Structure

Gases and the Atmosphere

Liquids, Solids, and Materials

Chemical Kinetics: Rates of Reactions

Chemical Equilibrium

The Chemistry of Solutes and Solutions

Acids and Bases

Additional Aqueous Equilibria

Thermodynamics: Directionality of Chemical Reactions

Nuclear Chemistry

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The value of E_cell at 25^$\circ$C for the cell shown below is +1.27 V. What is the value of E^$\circ$_cell? $The value of E<sub>cell</sub> at 25<sup> \circ </sup>C for the cell shown below is +1.27 V. What is the value of E<sup> \circ </sup><sub>cell</sub>?$