Question 1

What is the oxidation number of oxygen in H2O2?

Accepted Answer

A) 0 
B) +1 
C) +2 
D) -1 
E) -2 
A) 0 
B) +1 
C) +2 
D) -1 
E) -2 D

Question 2

The major product of a ________ fuel cell is water.

Accepted Answer

hydrogen

Question 3

Which substance does not undergo oxidation or reduction in the reaction below?
Pb + PbO2 + 2H2SO4 → 2PbSO4 + 2H2O

Accepted Answer

A) Pb 
B) H2SO4 
C) PbO2 
D) PbSO4 
E) The reaction above is not a redox reaction 
A) Pb 
B) H2SO4 
C) PbO2 
D) PbSO4 
E) The reaction above is not a redox reaction B

Question 4

What is the oxidation number of manganese in KMnO4?

Accepted Answer

A) +1 
B) +2 
C) +7 
D) +4 
E) +5 
A) +1 
B) +2 
C) +7 
D) +4 
E) +5

Question 5

The lithium ion battery has more energy per unit mass than nickel-cadmium batteries.

Accepted Answer

A) True 
 B)False

Question 6

The standard cell potential (E°cell)of the reaction below is -0.34 V.The value of   for the reaction is ________ kJ/mol. Cu (s)+ 2H+ (aq)→ Cu2+ (aq)+ H2 (g)

Accepted Answer

A) -0.34 
B) +66 
C) -130 
D) +130 
E) none of the above 
A) -0.34 
B) +66 
C) -130 
D) +130 
E) none of the above

Question 7

Which transformation below is an example of an oxidation in an electrochemical cell?

Accepted Answer

A) CO2 → C2O42- 
B) VO2+ → VO2+ 
C) NO → NO3- 
D) H2AsO4 → H3AsO3 
E) O2 → H2O2 
A) CO2 → C2O42- 
B) VO2+ → VO2+ 
C) NO → NO3- 
D) H2AsO4 → H3AsO3 
E) O2 → H2O2

Question 8

The standard cell potential (   )for the reaction below is +0.63 V.At 25 °C,the cell potential for this reaction is ________ V when [   ] = 3.0 M and [   ] =     (aq)+ Zn (s)→   (aq)+ Pb (s)

Accepted Answer

A) 0.51 
B) 0.86 
C) 0.40 
D) 0.75 
E) 0.63 
A) 0.51 
B) 0.86 
C) 0.40 
D) 0.75 
E) 0.63

Question 9

Which substance is the oxidizing agent in the reaction below?
Fe   (l)+ 2HI (g)→ Fe     (s)+ CO (g)+   (g)

Accepted Answer

A) HI 
B) Fe(CO)5 
C) Fe(CO)4I2 
D) CO 
E) H2 
A) HI 
B) Fe(CO)5 
C) Fe(CO)4I2 
D) CO 
E) H2

Question 10

Which substance is the oxidizing agent in the following reaction?
Fe2S3 + 12HNO3 → 2Fe(NO3)3 + 3S + 6NO2 + 6H2O

Accepted Answer

A) HNO3 
B) S 
C) NO2 
D) Fe2S3 
E) H2O 
A) HNO3 
B) S 
C) NO2 
D) Fe2S3 
E) H2O

Question 11

In a voltaic cell electrons flow from the anode to the cathode.

Accepted Answer

A) True 
 B)False

Question 12

A voltaic cell is constructed with two   -Zn electrodes,where the half-reaction is   +   → Zn (s)E° = -0.763 V The concentrations of zinc ion in the two compartments are 4.50 M and 1.11 ×   M,respectively.The cell emf is ________ V.

Accepted Answer

A) -1.88 ×   
B) -309 
C) 0.0772 
D) 0.154 
E) -0.761 
A) -1.88 ×   
B) -309 
C) 0.0772 
D) 0.154 
E) -0.761

Question 13

What is the oxidation number of bromine in the HBrO molecule?

Accepted Answer

A) +1 
B) +2 
C) 0 
D) -1 
E) -2 
A) +1 
B) +2 
C) 0 
D) -1 
E) -2

Question 14

Which of the halogens in Table 20.1 is the strongest oxidizing agent?

Accepted Answer

A) Cl2 
B) Br2 
C) F2 
D) I2 
E) All of the halogens have equal strength as oxidizing agents. 
A) Cl2 
B) Br2 
C) F2 
D) I2 
E) All of the halogens have equal strength as oxidizing agents.

Question 15

The standard cell potential (E°cell)for the voltaic cell based on the reaction below is ________ V. 2Cr (s)+ 3Fe2+ (aq)→ 3Fe (s)+ 2Cr3+ (aq)

Accepted Answer

A) +0.30 
B) +2.80 
C) +3.10 
D) +0.83 
E) -0.16 
A) +0.30 
B) +2.80 
C) +3.10 
D) +0.83 
E) -0.16

Question 16

The standard cell potential (   )for the reaction below is +1.10 V.The cell potential for this reaction is ________ V when the concentration of   and   Zn (s)+   (aq)→ Cu (s)+   (aq)

Accepted Answer

A) 1.42 
B) 1.26 
C) 0.94 
D) 0.78 
E) 1.10 
A) 1.42 
B) 1.26 
C) 0.94 
D) 0.78 
E) 1.10

Question 17

Corrosion of iron is retarded by ________.

Accepted Answer

A) the presence of salts 
B) high pH conditions 
C) low pH conditions 
D) both the presence of salts and high pH conditions 
E) both the presence of salts and low pH conditions 
A) the presence of salts 
B) high pH conditions 
C) low pH conditions 
D) both the presence of salts and high pH conditions 
E) both the presence of salts and low pH conditions

Question 18

In the electrochemical cell using the redox reaction below,the cathode half-reaction is ________. 2   (s)+ Sn (s)→   (aq)+ H2 (g)

Accepted Answer

A) 2H+ + 2e- → H2 
B) Sn → Sn2+ + 2e- 
C) 2H+ → H2 + 2e- 
D) Sn + 2e- → Sn2+ 
E) Sn +   → H2 
A) 2H+ + 2e- → H2 
B) Sn → Sn2+ + 2e- 
C) 2H+ → H2 + 2e- 
D) Sn + 2e- → Sn2+ 
E) Sn +   → H2

Question 19

________ is the reducing agent in the reaction below. Cr2O72- + 6S2O32- + 14H+ → 2Cr3+ + 3S4O62- + 7H2O

Accepted Answer

A) Cr2O72- 
B) S2O32- 
C) H+ 
D) Cr3+ 
E) S4O62- 
A) Cr2O72- 
B) S2O32- 
C) H+ 
D) Cr3+ 
E) S4O62-

Question 20

Which element is reduced in the reaction below?
Fe2+ + H+ + Cr2O72- → Fe3+ + Cr3+ +   O

Accepted Answer

A) Cr 
B) Fe 
C) H 
D) O 
A) Cr 
B) Fe 
C) H 
D) O

Exam 20: Electrochemistry

What is the oxidation number of oxygen in H2O2?

The major product of a ________ fuel cell is water.

Which substance does not undergo oxidation or reduction in the reaction below? Pb + PbO2 + 2H2SO4 → 2PbSO4 + 2H2O

What is the oxidation number of manganese in KMnO4?

The lithium ion battery has more energy per unit mass than nickel-cadmium batteries.

The standard cell potential (E°cell)of the reaction below is -0.34 V.The value of for the reaction is ________ kJ/mol. Cu (s)+ 2H+ (aq)→ Cu2+ (aq)+ H2 (g)

Which transformation below is an example of an oxidation in an electrochemical cell?

The standard cell potential ( )for the reaction below is +0.63 V.At 25 °C,the cell potential for this reaction is ________ V when [ ] = 3.0 M and [ ] = (aq)+ Zn (s)→ (aq)+ Pb (s)

Which substance is the oxidizing agent in the reaction below? Fe (l)+ 2HI (g)→ Fe (s)+ CO (g)+ (g)

Which substance is the oxidizing agent in the following reaction? Fe2S3 + 12HNO3 → 2Fe(NO3)3 + 3S + 6NO2 + 6H2O

In a voltaic cell electrons flow from the anode to the cathode.

A voltaic cell is constructed with two -Zn electrodes,where the half-reaction is + → Zn (s)E° = -0.763 V The concentrations of zinc ion in the two compartments are 4.50 M and 1.11 × M,respectively.The cell emf is ________ V.

What is the oxidation number of bromine in the HBrO molecule?

Which of the halogens in Table 20.1 is the strongest oxidizing agent?

The standard cell potential (E°cell)for the voltaic cell based on the reaction below is ________ V. 2Cr (s)+ 3Fe2+ (aq)→ 3Fe (s)+ 2Cr3+ (aq)

The standard cell potential ( )for the reaction below is +1.10 V.The cell potential for this reaction is ________ V when the concentration of and Zn (s)+ (aq)→ Cu (s)+ (aq)

Corrosion of iron is retarded by ________.

In the electrochemical cell using the redox reaction below,the cathode half-reaction is ________. 2 (s)+ Sn (s)→ (aq)+ H2 (g)

________ is the reducing agent in the reaction below. Cr2O72- + 6S2O32- + 14H+ → 2Cr3+ + 3S4O62- + 7H2O

Which element is reduced in the reaction below? Fe2+ + H+ + Cr2O72- → Fe3+ + Cr3+ + O

Introduction: Matter, energy, and Measurement

Atoms, molecules, and Ions

Chemical Reactions and Reaction Stoichiometry

Reactions in Aqueous Solution

Thermochemistry

Electronic Structure of Atoms

Periodic Properties of the Elements

Basic Concepts of Chemical Bonding

Molecular Geometry and Bonding Theories

Gases

Liquids and Intermolecular Forces

Solids and Modern Materials

Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acid-Base Equilibria

Additional Aspects of Aqueous Equilibria

Chemistry of the Environment

Chemical Thermodynamics

Nuclear Chemistry

Chemistry of the Nonmetals

Transition Metals and Coordination Chemistry

The Chemistry of Life: Organic and Biological Chemistry

Filters

What is the oxidation number of oxygen in H₂O₂?

Which substance does not undergo oxidation or reduction in the reaction below? Pb + PbO₂ + 2H₂SO₄ → 2PbSO₄ + 2H₂O

The standard cell potential (E°_cell)of the reaction below is -0.34 V.The value of for the reaction is ________ kJ/mol. Cu (s)+ 2H⁺ (aq)→ Cu²⁺ (aq)+ H₂ (g)

Which substance is the oxidizing agent in the following reaction? Fe₂S₃ + 12HNO₃ → 2Fe(NO₃)₃ + 3S + 6NO₂ + 6H₂O

The standard cell potential (E°_cell)for the voltaic cell based on the reaction below is ________ V. 2Cr (s)+ 3Fe²⁺ (aq)→ 3Fe (s)+ 2Cr³⁺ (aq)

In the electrochemical cell using the redox reaction below,the cathode half-reaction is ________. 2 (s)+ Sn (s)→ (aq)+ H₂ (g)

________ is the reducing agent in the reaction below. Cr₂O₇^2- + 6S₂O₃^2- + 14H⁺ → 2Cr³⁺ + 3S₄O₆^2- + 7H₂O

Which element is reduced in the reaction below? Fe²⁺ + H⁺ + Cr₂O₇^2- → Fe³⁺ + Cr³⁺ + O