Question 1

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 g 
A)  0.419 g 
B)  6.29 g 
C)  12.6 g 
D)  25.2 g 
E)  33.4 g D

Question 2

Which one of the following statements relating to the glass electrode is correct?

Accepted Answer

A)  The glass electrode detects hydrogen gas. 
B)  The glass of a glass electrode serves to conduct electrons. 
C)  When pH is measured, only a single electrode, the glass electrode, need be used. 
D)  The potential of the glass electrode varies linearly with the pH of the solution. 
E)  None of these choices are correct. 
A)  The glass electrode detects hydrogen gas. 
B)  The glass of a glass electrode serves to conduct electrons. 
C)  When pH is measured, only a single electrode, the glass electrode, need be used. 
D)  The potential of the glass electrode varies linearly with the pH of the solution. 
E)  None of these choices are correct. D

Question 3

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 minutes 
E)  37.1 minutes 
A)  6.2 minutes 
B)  12.4 minutes 
C)  18.6 minutes 
D)  24.7 minutes 
E)  37.1 minutes C

Question 4

A salt bridge provides a path for electrons to move between the anode and cathode compartments of a voltaic cell.

Accepted Answer

A) True 
 B)False

Question 5

What is the E°cell for the cell represented by the combination of the following half-reactions? ClO4(aq) + 8H(aq) + 8e   Cl-(aq) + 4H2O(l) E° = 1.389 V
VO2(aq) + 2H(aq) + e- j   VO(aq) + H2O(l) E° = 0.991 V

Accepted Answer

A)  -0.398 V 
B)  -2.380 V 
C)  0.398 V 
D)  2.380 V 
E)  None of these choices are correct. 
A)  -0.398 V 
B)  -2.380 V 
C)  0.398 V 
D)  2.380 V 
E)  None of these choices are correct.

Question 6

What product forms at the cathode during the electrolysis of molten lithium iodide?

Accepted Answer

A)  Li+(l) 
B)  Li(l) 
C)  I-(l) 
D)  I2(g) 
E)  I3-(l) 
A)  Li+(l) 
B)  Li(l) 
C)  I-(l) 
D)  I2(g) 
E)  I3-(l)

Question 7

When metal A is placed in a solution of metal ions B2+, a reaction occurs between A and B2+, and metal ions A2+ appear in the solution. When metal B is placed in acid solution, gas bubbles form on its surface. When metal A is placed in a solution of metal ions C2+, no reaction occurs. Which of the following reactions would not occur spontaneously?

Accepted Answer

A)  C(s) + 2H+(aq) → H2(g) + C+(aq) 
B)  C(s) + A2+(aq) → A(s) + C2+(aq) 
C)  B(s) + C2+(aq) → C(s) + B2+(aq) 
D)  A(s) + 2H+(aq) → H2(g) + A2+(aq) 
E)  B(s) + 2H+(aq) → H2(g) + B2+(aq) 
A)  C(s) + 2H+(aq) → H2(g) + C+(aq) 
B)  C(s) + A2+(aq) → A(s) + C2+(aq) 
C)  B(s) + C2+(aq) → C(s) + B2+(aq) 
D)  A(s) + 2H+(aq) → H2(g) + A2+(aq) 
E)  B(s) + 2H+(aq) → H2(g) + B2+(aq)

Question 8

The line notation, Al(s) | Al3+(aq) || Co2+(aq) | Co(s), indicates that

Accepted Answer

A)  Co is the reducing agent. 
B)  Co2+ ions are oxidized. 
C)  Al is the reducing agent. 
D)  Al3+ is the reducing agent. 
E)  aluminum metal is the cathode. 
A)  Co is the reducing agent. 
B)  Co2+ ions are oxidized. 
C)  Al is the reducing agent. 
D)  Al3+ is the reducing agent. 
E)  aluminum metal is the cathode.

Question 9

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 these choices are correct. 
A)  -0.28 V 
B)  -0.96 V 
C)  0.28 V 
D)  0.96 V 
E)  None of these choices are correct.

Question 10

Consider the following balanced redox reaction Mn2+(aq) + S2O82-(aq) + 2H2O(l) → MnO2(s) + 4H(aq) + 2SO42-(aq)
Which of the following statements is true?

Accepted Answer

A)  Mn2+(aq) is the oxidizing agent and is reduced. 
B)  Mn2+(aq) is the oxidizing agent and is oxidized. 
C)  Mn2+(aq) is the reducing agent and is oxidized. 
D)  Mn2+(aq) is the reducing agent and is reduced. 
E)  Manganese does not change its oxidation number in this reaction. 
A)  Mn2+(aq) is the oxidizing agent and is reduced. 
B)  Mn2+(aq) is the oxidizing agent and is oxidized. 
C)  Mn2+(aq) is the reducing agent and is oxidized. 
D)  Mn2+(aq) is the reducing agent and is reduced. 
E)  Manganese does not change its oxidation number in this reaction.

Question 11

What mass of copper will be deposited when 18.2 A are passed through a CuSO4 solution for 45.0 minutes?

Accepted Answer

A)  16.2 g 
B)  33.4 g 
C)  40.6 g 
D)  81.3 g 
E)  163 g 
A)  16.2 g 
B)  33.4 g 
C)  40.6 g 
D)  81.3 g 
E)  163 g

Question 12

The line notation, Pt | H2(g) | H+(aq) || Cu2+(aq) | Cu(s), indicates that

Accepted Answer

A)  copper metal is a product of the cell reaction. 
B)  hydrogen gas (H2) is a product of the cell reaction. 
C)  Cu is the anode. 
D)  Pt is the cathode. 
E)  Cu2+ is the reducing agent. 
A)  copper metal is a product of the cell reaction. 
B)  hydrogen gas (H2) is a product of the cell reaction. 
C)  Cu is the anode. 
D)  Pt is the cathode. 
E)  Cu2+ is the reducing agent.

Question 13

Select the incorrect statement relating to the corrosion of iron in air.

Accepted Answer

A)  Fe2+ is formed in the anodic region. 
B)  O2 is oxidized in the cathodic region. 
C)  Electrons travel through the iron metal between the anodic and cathodic regions. 
D)  Moisture provides a pathway for ions to migrate. 
E)  Rust is a hydrated form of iron(III) oxide. 
A)  Fe2+ is formed in the anodic region. 
B)  O2 is oxidized in the cathodic region. 
C)  Electrons travel through the iron metal between the anodic and cathodic regions. 
D)  Moisture provides a pathway for ions to migrate. 
E)  Rust is a hydrated form of iron(III) oxide.

Question 14

Which, if any, of the following metals would be capable of acting as a sacrificial anode when used with iron pipe? E°Fe = -0.44 V; all E° values refer to the M2+/M half-cell reactions.

Accepted Answer

A)  copper, Cu, E° = 0.15 V 
B)  cobalt, Co, E° = -0.28 V 
C)  chromium, Cr, E° = -0.74 V 
D)  tin, Sn, E° = -0.14 V 
E)  None of these metals would be capable of acting as a sacrificial anode with iron. 
A)  copper, Cu, E° = 0.15 V 
B)  cobalt, Co, E° = -0.28 V 
C)  chromium, Cr, E° = -0.74 V 
D)  tin, Sn, E° = -0.14 V 
E)  None of these metals would be capable of acting as a sacrificial anode with iron.

Question 15

When the following redox equation is balanced with smallest whole number coefficients, the coefficient for the iodide ion will be I-(aq) + NO3-(aq) → NO(g) + I2(s) (acidic solution)

Accepted Answer

A)  2. 
B)  3. 
C)  6. 
D)  8. 
E)  None of these choices are correct. 
A)  2. 
B)  3. 
C)  6. 
D)  8. 
E)  None of these choices are correct.

Question 16

The redox reaction of peroxydisulfate with iodide has been used for many years as part of the iodine clock reaction which introduces students to kinetics. If E°cell = 1.587 V and E° of the cathode half-cell is 0.536 V, what is E° of the anode half-cell? S2O82-(aq) + 2H+ + 2I-(aq) → 2HSO4-(aq) + I2(aq)

Accepted Answer

A)  -1.051 V 
B)  -2.123 V 
C)  1.051 V 
D)  2.123 V 
E)  None of these choices are correct. 
A)  -1.051 V 
B)  -2.123 V 
C)  1.051 V 
D)  2.123 V 
E)  None of these choices are correct.

Question 17

In the electrolyte of an electrochemical cell, current is carried by anions moving toward the anode and cations moving in the opposite direction.

Accepted Answer

A) True 
 B)False

Question 18

Consider the nonaqueous cell reaction 2Na(l) + FeCl2(s)   2NaCl(s) + Fe(s)
For which E° cell = 2.35 V at 200°C. ΔG° at this temperature is

Accepted Answer

A)  453 kJ. 
B)  -453 kJ. 
C)  907 kJ. 
D)  -907 kJ. 
E)  None of these choices are correct. 
A)  453 kJ. 
B)  -453 kJ. 
C)  907 kJ. 
D)  -907 kJ. 
E)  None of these choices are correct.

Question 19

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 ion 
A)  potassium ion 
B)  nitrate ion 
C)  water 
D)  oxygen 
E)  hydronium ion

Question 20

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

Exam 21: Electrochemistry Chemical Change and Electrical Work

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

Which one of the following statements relating to the glass electrode is correct?

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?

A salt bridge provides a path for electrons to move between the anode and cathode compartments of a voltaic cell.

What is the E°cell for the cell represented by the combination of the following half-reactions? ClO4(aq) + 8H(aq) + 8e Cl-(aq) + 4H2O(l) E° = 1.389 V VO2(aq) + 2H(aq) + e- j VO(aq) + H2O(l) E° = 0.991 V

What product forms at the cathode during the electrolysis of molten lithium iodide?

The line notation, Al(s) | Al3+(aq) || Co2+(aq) | Co(s), indicates that

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)

Consider the following balanced redox reaction Mn2+(aq) + S2O82-(aq) + 2H2O(l) → MnO2(s) + 4H(aq) + 2SO42-(aq) Which of the following statements is true?

What mass of copper will be deposited when 18.2 A are passed through a CuSO4 solution for 45.0 minutes?

The line notation, Pt | H2(g) | H+(aq) || Cu2+(aq) | Cu(s), indicates that

Select the incorrect statement relating to the corrosion of iron in air.

Which, if any, of the following metals would be capable of acting as a sacrificial anode when used with iron pipe? E°Fe = -0.44 V; all E° values refer to the M2+/M half-cell reactions.

When the following redox equation is balanced with smallest whole number coefficients, the coefficient for the iodide ion will be I-(aq) + NO3-(aq) → NO(g) + I2(s) (acidic solution)

In the electrolyte of an electrochemical cell, current is carried by anions moving toward the anode and cations moving in the opposite direction.

Consider the nonaqueous cell reaction 2Na(l) + FeCl2(s) 2NaCl(s) + Fe(s) For which E° cell = 2.35 V at 200°C. ΔG° at this temperature is

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

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

Keys to Studying Chemistry Definitions, Units, and Problem Solving

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces Liquids, Solids, and Phase Changes

The Properties of Mixtures Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics Rates and Mechanisms of Chemical Reactions

Equilibrium the Extent of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics Entropy, Free Energy, and Reaction Direction

The Elements in Nature and Industry

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

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?

What is the E°_cell for the cell represented by the combination of the following half-reactions? ClO₄(aq) + 8H(aq) + 8e Cl-(aq) + 4H₂O(l) E° = 1.389 V VO₂(aq) + 2H(aq) + e^- j VO(aq) + H₂O(l) E° = 0.991 V

The line notation, Al(s) | Al³⁺(aq) || Co²⁺(aq) | Co(s), indicates that

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)

Consider the following balanced redox reaction Mn²+(aq) + S₂O8^2-(aq) + 2H₂O(l) → MnO₂(s) + 4H(aq) + 2SO₄^2-(aq) Which of the following statements is true?

What mass of copper will be deposited when 18.2 A are passed through a CuSO₄ solution for 45.0 minutes?

The line notation, Pt | H₂(g) | H⁺(aq) || Cu²⁺(aq) | Cu(s), indicates that

Which, if any, of the following metals would be capable of acting as a sacrificial anode when used with iron pipe? E°_Fe = -0.44 V; all E° values refer to the M²⁺/M half-cell reactions.

When the following redox equation is balanced with smallest whole number coefficients, the coefficient for the iodide ion will be I-(aq) + NO₃-(aq) → NO(g) + I₂(s) (acidic solution)

Consider the nonaqueous cell reaction 2Na(l) + FeCl₂(s) 2NaCl(s) + Fe(s) For which E°_cell = 2.35 V at 200°C. ΔG° at this temperature is