Question 1

Which pair of half-reactions could be used to electroplate silver onto iron?

Accepted Answer

A)  reduction: Ag+ + e- F1F1F1S1F1F1F10F1F1F1S1F1F1F10Ag; oxidation: Ag F1F1F1S1F1F1F10F1F1F1S1F1F1F10Ag+ + e- 
B)  reduction: Ag F1F1F1S1F1F1F10F1F1F1S1F1F1F10Ag+ + e-; oxidation: Ag+ + e- F1F1F1S1F1F1F10F1F1F1S1F1F1F10Ag 
C)  reduction: Fe2+ + 2 e- F1F1F1S1F1F1F10F1F1F1S1F1F1F10Fe; oxidation: Fe F1F1F1S1F1F1F10F1F1F1S1F1F1F10Fe2+ + 2 e- 
D)  reduction: Fe F1F1F1S1F1F1F10F1F1F1S1F1F1F10Fe2+ + 2 e-; oxidation: Fe2+ + 2 e- F1F1F1S1F1F1F10F1F1F1S1F1F1F10Fe

Question 2

If the accompanying drawing of an electrochemical cell represents an iron-nickel cell, use the partial activity series included to select the half-reaction represented by the LEFT side of the cell.  Zn F1F1F1S1F1F1F10 Zn2+ + 2e- Fe F1F1F1S1F1F1F10 Fe2+ + 2e-
Co F1F1F1S1F1F1F10 Co2+ + 2e-
Ni F1F1F1S1F1F1F10 Ni2+ + 2e-
Cu F1F1F1S1F1F1F10 Cu2+ + 2e-

Accepted Answer

A)  Fe F1F1F1S1F1F1F10 Fe2+ + 2e- 
B)  Ni F1F1F1S1F1F1F10 Ni2+ + 2e- 
C)  Fe2+ + 2e- F1F1F1S1F1F1F10 Fe 
D)  Ni2+ + 2e- F1F1F1S1F1F1F10 Ni

Question 3

In the context of chemical reactions, oxidation refers to the:

Accepted Answer

A)  gain of electrons. 
B)  loss of electrons. 
C)  loss of oxygen. 
D)  loss of water.

Question 4

What are the coefficients of the balanced equation that represents the reaction in a magnesium/iron electrochemical cell? 
Mg (s) + Fe2+ (aq) F1F1F1S1F1F1F10 Fe (s) + Mg2+ (aq)

Accepted Answer

A)  1, 1, 1, 1 
B)  1, 2, 2, 1 
C)  2, 1, 1, 2 
D)  1, 2, 1, 2

Question 5

Using the accompanying drawing of an electrochemical cell, identify the components labeled 1, 2, and 5, respectively.

Accepted Answer

A)  salt bridge, anode, cathode 
B)  salt bridge, cathode, anode 
C)  cathode, anode, salt bridge 
D)  anode, cathode, salt bridge

Question 6

Use the partial activity series included to determine which reaction will NOT occur spontaneously. Zn F1F1F1S1F1F1F10 Zn2+ + 2e-
Fe F1F1F1S1F1F1F10 Fe2+ + 2e-
Co F1F1F1S1F1F1F10 Co2+ + 2e-
Ni F1F1F1S1F1F1F10 Ni2+ + 2e-
Cu F1F1F1S1F1F1F10 Cu2+ + 2e-

Accepted Answer

A)  Fe (s) + Co2+ (aq) F1F1F1S1F1F1F10 Fe2+ (aq) + Co (s) 
B)  Zn (s) + Ni2+ (aq) F1F1F1S1F1F1F10 Zn2+ (aq) + Ni (s) 
C)  Cu (s) + Fe2+ (aq) F1F1F1S1F1F1F10 Cu2+ (aq) + Fe (s) 
D)  Ni (s) + Cu2+ (aq) F1F1F1S1F1F1F10 Ni2+ (aq) + Cu (s)

Question 7

Consider an electrochemical cell consisting of zinc and cobalt half-cells. Use the partial activity series included to determine the direction in which the electrons in the wire will flow. 
Zn F1F1F1S1F1F1F10 Zn2+ + 2e-
Fe F1F1F1S1F1F1F10 Fe2+ + 2e-
Co F1F1F1S1F1F1F10 Co2+ + 2e-
Ni F1F1F1S1F1F1F10 Ni2+ + 2e-
Cu F1F1F1S1F1F1F10 Cu2+ + 2e-

Accepted Answer

A)  from the zinc anode to the cobalt cathode 
B)  from the zinc cathode to the cobalt anode 
C)  from the cobalt anode to the zinc cathode 
D)  from the cobalt cathode to the zinc anode

Question 8

Knowing that sodium and potassium react violently with water, predict which element will also react with water.

Accepted Answer

A)  cesium 
B)  aluminum 
C)  zinc 
D)  It is impossible to predict accurately from the information given.

Question 9

What is the oxidation number of sulfur in the sulfite ion, SO32-?

Accepted Answer

A)  -2 
B)  +2 
C)  +6 
D)  +4

Question 10

Given the accompanying partial activity series, which element(s) can reduce copper(II) to elemental copper? 
Zn F1F1F1S1F1F1F10 Zn2+ + 2e-
Fe F1F1F1S1F1F1F10 Fe2+ + 2e-
Co F1F1F1S1F1F1F10 Co2+ + 2e-
Ni F1F1F1S1F1F1F10 Ni2+ + 2e-
Cu F1F1F1S1F1F1F10 Cu2+ + 2e-

Accepted Answer

A)  nickel 
B)  iron 
C)  zinc 
D)  nickel, iron, and zinc 
E)  None of these elements can reduce copper(II) to elemental copper.

Question 11

The oxidation half-reaction for the reaction of zinc with hydrochloric acid is:

Accepted Answer

A)  Zn2+ + 2 e- F1F1F1S1F1F1F10 Zn. 
B)  Zn F1F1F1S1F1F1F10 Zn2+ + 2 e-. 
C)  H2 F1F1F1S1F1F1F10 2 H+ + 2 e-. 
D)  2 H+ + 2 e- F1F1F1S1F1F1F10 H2.

Question 12

Which example does NOT illustrate a redox reaction?

Accepted Answer

A)  metal and nonmetal 
B)  double displacement 
C)  single displacement 
D)  combustion

Question 13

What is the oxidation number of carbon in carbon monoxide, CO?

Accepted Answer

A)  -2 
B)  +2 
C)  +6 
D)  +4

Question 14

If the accompanying drawing of an electrochemical cell represents an iron-nickel cell, use the partial activity series included to identify the components labeled 1, 2, 3, and 4 respectively.  Zn F1F1F1S1F1F1F10 Zn2+ + 2e- Fe F1F1F1S1F1F1F10 Fe2+ + 2e-
Co F1F1F1S1F1F1F10 Co2+ + 2e-
Ni F1F1F1S1F1F1F10F1F1F1S1F1F1F10Ni2+ + 2e-
Cu F1F1F1S1F1F1F10 Cu2+ + 2e-

Accepted Answer

A)  iron, nickel, iron ion solution, nickel ion solution 
B)  nickel, iron, iron ion solution, nickel ion solution 
C)  nickel, iron, nickel ion solution, iron ion solution 
D)  iron, nickel, nickel ion solution, iron ion solution

Question 15

What are the coefficients of the balanced equation that represents the reaction in a magnesium/aluminum electrochemical cell? 
Mg (s) + Al3+ (aq) F1F1F1S1F1F1F10 Al (s) + Mg2+ (aq)

Accepted Answer

A)  1, 1, 1, 1 
B)  3, 2, 2, 3 
C)  2, 3, 3, 2 
D)  1, 2, 1, 3

Question 16

What is the oxidation number of sulfur in sulfur trioxide, SO3?

Accepted Answer

A)  -2 
B)  +2 
C)  +6 
D)  +4

Question 17

Which pair of half-reactions takes place in a fuel cell?

Accepted Answer

A)  reduction: O2 + 4 H+ + 4 e- F1F1F1S1F1F1F10F1F1F1S1F1F1F102H2O; oxidation: H2 F1F1F1S1F1F1F10F1F1F1S1F1F1F102 H+ + 2 e- 
B)  reduction: H2 F1F1F1S1F1F1F10F1F1F1S1F1F1F102 H+ + 2 e-; oxidation: O2 + 4 H+ + 4 e- F1F1F1S1F1F1F10F1F1F1S1F1F1F102 H2O 
C)  reduction: O2 + 4 H+ + 4 e- F1F1F1S1F1F1F10F1F1F1S1F1F1F102H2O; oxidation: 2 H+ + 2 e- F1F1F1S1F1F1F10F1F1F1S1F1F1F10H2 
D)  reduction: H2 F1F1F1S1F1F1F10F1F1F1S1F1F1F102 H+ + 2 e-; oxidation: 2 H2O F1F1F1S1F1F1F10F1F1F1S1F1F1F10O2 + 4H+ + 4 e-

Question 18

Write the balanced net ionic equation for the reaction consisting of the two half-reactions given. 
Cu F1F1F1S1F1F1F10 Cu2+ + 2e-
Au3+ + 3e- F1F1F1S1F1F1F10 Au

Accepted Answer

A)  Cu (s) + Au3+ (aq) F1F1F1S1F1F1F10 Cu2+ (aq) + Au (s) 
B)  3 Cu (s) + 2 Au3+ (aq) F1F1F1S1F1F1F10 3 Cu2+ (aq) + 2 Au (s) 
C)  2 Au (s) + 3 Cu2+ (aq) F1F1F1S1F1F1F10 2 Au3+ (aq) + 3 Cu (s) 
D)  Au (s) + Cu2+ (aq) F1F1F1S1F1F1F10 Au3+ (aq) + Cu (s)

Question 19

Given the accompanying partial activity series, predict which element or ion will react with cobalt, Co. 
Zn F1F1F1S1F1F1F10 Zn2+ + 2e-
Fe F1F1F1S1F1F1F10 Fe2+ + 2e-
Co F1F1F1S1F1F1F10 Co2+ + 2e-
Ni F1F1F1S1F1F1F10 Ni2+ + 2e-
Cu F1F1F1S1F1F1F10 Cu2+ + 2e-

Accepted Answer

A)  Zn 
B)  Fe2+ 
C)  Ni 
D)  Cu2+

Question 20

Given the accompanying partial activity series, which element(s) will NOT react with acid? 
Zn F1F1F1S1F1F1F10 Zn2+ + 2e-
Fe F1F1F1S1F1F1F10 Fe2+ + 2e-
Ni F1F1F1S1F1F1F10 Ni2+ + 2e-
H2 F1F1F1S1F1F1F10 2H+ + 2e-
Cu F1F1F1S1F1F1F10 Cu2+ + 2e-
Ag F1F1F1S1F1F1F10 Ag+ + e-

Accepted Answer

A)  nickel 
B)  iron 
C)  silver 
D)  nickel, iron, and silver 
E)  All of these elements will react with acid.

Exam 14: Oxidation-Reduction Reactions

Which pair of half-reactions could be used to electroplate silver onto iron?

In the context of chemical reactions, oxidation refers to the:

What are the coefficients of the balanced equation that represents the reaction in a magnesium/iron electrochemical cell? Mg (s) + Fe²⁺ (aq)  Fe (s) + Mg²⁺ (aq)

Using the accompanying drawing of an electrochemical cell, identify the components labeled 1, 2, and 5, respectively.

Use the partial activity series included to determine which reaction will NOT occur spontaneously. Zn  Zn²⁺ + 2e^- Fe  Fe²⁺ + 2e^- Co  Co²⁺ + 2e^- Ni  Ni²⁺ + 2e^- Cu  Cu²⁺ + 2e^-

Consider an electrochemical cell consisting of zinc and cobalt half-cells. Use the partial activity series included to determine the direction in which the electrons in the wire will flow. Zn  Zn²⁺ + 2e^- Fe  Fe²⁺ + 2e^- Co  Co²⁺ + 2e^- Ni  Ni²⁺ + 2e^- Cu  Cu²⁺ + 2e^-

Knowing that sodium and potassium react violently with water, predict which element will also react with water.

What is the oxidation number of sulfur in the sulfite ion, SO₃²^-?

Given the accompanying partial activity series, which element(s) can reduce copper(II) to elemental copper? Zn  Zn²⁺ + 2e^- Fe  Fe²⁺ + 2e^- Co  Co²⁺ + 2e^- Ni  Ni²⁺ + 2e^- Cu  Cu²⁺ + 2e^-

The oxidation half-reaction for the reaction of zinc with hydrochloric acid is:

Which example does NOT illustrate a redox reaction?

What is the oxidation number of carbon in carbon monoxide, CO?

What are the coefficients of the balanced equation that represents the reaction in a magnesium/aluminum electrochemical cell? Mg (s) + Al³⁺ (aq)  Al (s) + Mg²⁺ (aq)

What is the oxidation number of sulfur in sulfur trioxide, SO₃?

Which pair of half-reactions takes place in a fuel cell?

Write the balanced net ionic equation for the reaction consisting of the two half-reactions given. Cu  Cu²⁺ + 2e^- Au³⁺ + 3e^-  Au

Given the accompanying partial activity series, predict which element or ion will react with cobalt, Co. Zn  Zn²⁺ + 2e^- Fe  Fe²⁺ + 2e^- Co  Co²⁺ + 2e^- Ni  Ni²⁺ + 2e^- Cu  Cu²⁺ + 2e^-

Given the accompanying partial activity series, which element(s) will NOT react with acid? Zn  Zn²⁺ + 2e^- Fe  Fe²⁺ + 2e^- Ni  Ni²⁺ + 2e^- H₂  2H⁺ + 2e^- Cu  Cu²⁺ + 2e^- Ag  Ag⁺ + e^-

Exam 14: Oxidation-Reduction Reactions

Which pair of half-reactions could be used to electroplate silver onto iron?

If the accompanying drawing of an electrochemical cell represents an iron-nickel cell, use the partial activity series included to select the half-reaction represented by the LEFT side of the cell. Zn  Zn2+ + 2e- Fe  Fe2+ + 2e- Co  Co2+ + 2e- Ni  Ni2+ + 2e- Cu  Cu2+ + 2e-

In the context of chemical reactions, oxidation refers to the:

What are the coefficients of the balanced equation that represents the reaction in a magnesium/iron electrochemical cell? Mg (s) + Fe2+ (aq)  Fe (s) + Mg2+ (aq)

Using the accompanying drawing of an electrochemical cell, identify the components labeled 1, 2, and 5, respectively.

Use the partial activity series included to determine which reaction will NOT occur spontaneously. Zn  Zn2+ + 2e- Fe  Fe2+ + 2e- Co  Co2+ + 2e- Ni  Ni2+ + 2e- Cu  Cu2+ + 2e-

Consider an electrochemical cell consisting of zinc and cobalt half-cells. Use the partial activity series included to determine the direction in which the electrons in the wire will flow. Zn  Zn2+ + 2e- Fe  Fe2+ + 2e- Co  Co2+ + 2e- Ni  Ni2+ + 2e- Cu  Cu2+ + 2e-

Knowing that sodium and potassium react violently with water, predict which element will also react with water.

What is the oxidation number of sulfur in the sulfite ion, SO32-?

Given the accompanying partial activity series, which element(s) can reduce copper(II) to elemental copper? Zn  Zn2+ + 2e- Fe  Fe2+ + 2e- Co  Co2+ + 2e- Ni  Ni2+ + 2e- Cu  Cu2+ + 2e-

The oxidation half-reaction for the reaction of zinc with hydrochloric acid is:

Which example does NOT illustrate a redox reaction?

What is the oxidation number of carbon in carbon monoxide, CO?

If the accompanying drawing of an electrochemical cell represents an iron-nickel cell, use the partial activity series included to identify the components labeled 1, 2, 3, and 4 respectively. Zn  Zn2+ + 2e- Fe  Fe2+ + 2e- Co  Co2+ + 2e- Ni Ni2+ + 2e- Cu  Cu2+ + 2e-

What are the coefficients of the balanced equation that represents the reaction in a magnesium/aluminum electrochemical cell? Mg (s) + Al3+ (aq)  Al (s) + Mg2+ (aq)

What is the oxidation number of sulfur in sulfur trioxide, SO3?

Which pair of half-reactions takes place in a fuel cell?

Write the balanced net ionic equation for the reaction consisting of the two half-reactions given. Cu  Cu2+ + 2e- Au3+ + 3e-  Au

Given the accompanying partial activity series, predict which element or ion will react with cobalt, Co. Zn  Zn2+ + 2e- Fe  Fe2+ + 2e- Co  Co2+ + 2e- Ni  Ni2+ + 2e- Cu  Cu2+ + 2e-

Given the accompanying partial activity series, which element(s) will NOT react with acid? Zn  Zn2+ + 2e- Fe  Fe2+ + 2e- Ni  Ni2+ + 2e- H2  2H+ + 2e- Cu  Cu2+ + 2e- Ag  Ag+ + e-

What are the coefficients of the balanced equation that represents the reaction in a magnesium/iron electrochemical cell? Mg (s) + Fe²⁺ (aq)  Fe (s) + Mg²⁺ (aq)

Use the partial activity series included to determine which reaction will NOT occur spontaneously. Zn  Zn²⁺ + 2e^- Fe  Fe²⁺ + 2e^- Co  Co²⁺ + 2e^- Ni  Ni²⁺ + 2e^- Cu  Cu²⁺ + 2e^-

Consider an electrochemical cell consisting of zinc and cobalt half-cells. Use the partial activity series included to determine the direction in which the electrons in the wire will flow. Zn  Zn²⁺ + 2e^- Fe  Fe²⁺ + 2e^- Co  Co²⁺ + 2e^- Ni  Ni²⁺ + 2e^- Cu  Cu²⁺ + 2e^-

What is the oxidation number of sulfur in the sulfite ion, SO₃²^-?

Given the accompanying partial activity series, which element(s) can reduce copper(II) to elemental copper? Zn  Zn²⁺ + 2e^- Fe  Fe²⁺ + 2e^- Co  Co²⁺ + 2e^- Ni  Ni²⁺ + 2e^- Cu  Cu²⁺ + 2e^-

What are the coefficients of the balanced equation that represents the reaction in a magnesium/aluminum electrochemical cell? Mg (s) + Al³⁺ (aq)  Al (s) + Mg²⁺ (aq)

What is the oxidation number of sulfur in sulfur trioxide, SO₃?

Write the balanced net ionic equation for the reaction consisting of the two half-reactions given. Cu  Cu²⁺ + 2e^- Au³⁺ + 3e^-  Au

Given the accompanying partial activity series, predict which element or ion will react with cobalt, Co. Zn  Zn²⁺ + 2e^- Fe  Fe²⁺ + 2e^- Co  Co²⁺ + 2e^- Ni  Ni²⁺ + 2e^- Cu  Cu²⁺ + 2e^-

Given the accompanying partial activity series, which element(s) will NOT react with acid? Zn  Zn²⁺ + 2e^- Fe  Fe²⁺ + 2e^- Ni  Ni²⁺ + 2e^- H₂  2H⁺ + 2e^- Cu  Cu²⁺ + 2e^- Ag  Ag⁺ + e^-