Question 1

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

Accepted Answer

A) True 
 B)False  True

Question 2

The balanced half-reaction in which dichromate ion is reduced to chromium(III)ion is a __________ process.

Accepted Answer

A) four-electron 
B) twelve-electron 
C) three-electron 
D) six-electron 
E) two-electron 
A) four-electron 
B) twelve-electron 
C) three-electron 
D) six-electron 
E) two-electron D

Question 3

What is the oxidation number of sulfur in the HSO4- ion?

Accepted Answer

A) -2 
B) +1 
C) +2 
D) +4 
E) +6 
A) -2 
B) +1 
C) +2 
D) +4 
E) +6 E

Question 4

__________ 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 5

Which transformation could take place at the anode of an electrochemical cell?

Accepted Answer

A) Cr2O72- → Cr2+ 
B) F2 to F- 
C) O2 to H2O 
D) HAsO2 to As 
E) None of the above could take place at the anode. 
A) Cr2O72- → Cr2+ 
B) F2 to F- 
C) O2 to H2O 
D) HAsO2 to As 
E) None of the above could take place at the anode.

Question 6

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 7

The quantity of charge passing a point in a circuit in one second when the current is one ampere is called a __________.

Accepted Answer

The answer of The quantity of charge passing a point...

Question 8

The standard cell potential (E°cell)for the voltaic cell based on the reaction below is __________ V. Cr (s)+ 3Fe3+ (aq)→ 3Fe2+ (aq)+ Cr3+ (aq)

Accepted Answer

A) -1.45 
B) +2.99 
C) +1.51 
D) +3.05 
E) +1.57 
A) -1.45 
B) +2.99 
C) +1.51 
D) +3.05 
E) +1.57

Question 9

In the formula ΔG = -nFE, F is the __________.

Accepted Answer

Faraday constant or

Question 10

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 11

In a lead-acid battery, the electrodes are consumed. In this battery,

Accepted Answer

A) the anode is Pb. 
B) the anode is PbSO4. 
C) the anode is PbO2. 
D) the cathode is PbSO4. 
E) the cathode is Pb. 
A) the anode is Pb. 
B) the anode is PbSO4. 
C) the anode is PbO2. 
D) the cathode is PbSO4. 
E) the cathode is Pb.

Question 12

The electrolysis of molten AlCl3 for 3.25 hr with an electrical current of 15.0 A produces __________ g of aluminum metal.

Accepted Answer

A) 147 
B) 0.606 
C) 4.55 × 10-3 
D) 16.4 
E) 49.1 
A) 147 
B) 0.606 
C) 4.55 × 10-3 
D) 16.4 
E) 49.1

Question 13

How many seconds are required to produce 4.00 g of aluminum metal from the electrolysis of molten AlCl3 with an electrical current of 12.0 A?

Accepted Answer

A) 27.0 
B) 9.00 
C) 1.19 × 103 
D) 2.90 × 105 
E) 3.57 × 103 
A) 27.0 
B) 9.00 
C) 1.19 × 103 
D) 2.90 × 105 
E) 3.57 × 103

Question 14

A voltaic cell is constructed with two silver-silver chloride electrodes, where the half-reaction is AgCl (s)+ e- → Ag (s)+ Cl- (aq)E° = +0.222 V
The concentrations of chloride ion in the two compartments are 0.0222 M and 2.22 M, respectively. The cell emf is __________ V.

Accepted Answer

A) 0.212 
B) 0.118 
C) 0.00222 
D) 22.2 
E) 0.232 
A) 0.212 
B) 0.118 
C) 0.00222 
D) 22.2 
E) 0.232

Question 15

When iron is coated with a thin layer of zinc to protect against corrosion, the iron is said to be __________.

Accepted Answer

The answer of When iron is coated with a thin...

Question 16

The anode of the alkaline battery is powdered zinc in a gel that contacts __________.

Accepted Answer

KOH; potas

Question 17

The more __________ the value of E°red, the greater the driving force for reduction.

Accepted Answer

A) positive 
B) negative 
C) exothermic 
D) endothermic 
E) extensive 
A) positive 
B) negative 
C) exothermic 
D) endothermic 
E) extensive

Question 18

Which substance is the oxidizing agent in the reaction below? Pb + PbO2 + 2H2SO4 → 2PbSO4 + 2H2O

Accepted Answer

A) Pb 
B) H2SO4 
C) PbO2 
D) PbSO4 
E) H2O 
A) Pb 
B) H2SO4 
C) PbO2 
D) PbSO4 
E) H2O

Question 19

The balanced half-reaction in which sulfate ion is reduced to sulfite ion is a __________ process.

Accepted Answer

A) four-electron 
B) one-electron 
C) two-electron 
D) three-electron 
E) six-electron 
A) four-electron 
B) one-electron 
C) two-electron 
D) three-electron 
E) six-electron

Question 20

The standard cell potential (E°cell)for the reaction below is +1.10 V. The cell potential for this reaction is __________ V when the concentration of [Cu2+] = 1.0 × 10-5 M and [Zn2+] = 3.5 M. Zn (s)+ Cu2+ (aq)→ Cu (s)+ Zn2+ (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

Exam 20: Electrochemistry

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

The balanced half-reaction in which dichromate ion is reduced to chromium(III)ion is a __________ process.

What is the oxidation number of sulfur in the HSO4- ion?

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

Which transformation could take place at the anode of an electrochemical cell?

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

The quantity of charge passing a point in a circuit in one second when the current is one ampere is called a __________.

The standard cell potential (E°cell)for the voltaic cell based on the reaction below is __________ V. Cr (s)+ 3Fe3+ (aq)→ 3Fe2+ (aq)+ Cr3+ (aq)

In the formula ΔG = -nFE, F is the __________.

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 a lead-acid battery, the electrodes are consumed. In this battery,

The electrolysis of molten AlCl3 for 3.25 hr with an electrical current of 15.0 A produces __________ g of aluminum metal.

How many seconds are required to produce 4.00 g of aluminum metal from the electrolysis of molten AlCl3 with an electrical current of 12.0 A?

A voltaic cell is constructed with two silver-silver chloride electrodes, where the half-reaction is AgCl (s)+ e- → Ag (s)+ Cl- (aq)E° = +0.222 V The concentrations of chloride ion in the two compartments are 0.0222 M and 2.22 M, respectively. The cell emf is __________ V.

When iron is coated with a thin layer of zinc to protect against corrosion, the iron is said to be __________.

The anode of the alkaline battery is powdered zinc in a gel that contacts __________.

The more __________ the value of E°red, the greater the driving force for reduction.

Which substance is the oxidizing agent in the reaction below? Pb + PbO2 + 2H2SO4 → 2PbSO4 + 2H2O

The balanced half-reaction in which sulfate ion is reduced to sulfite ion is a __________ process.

The standard cell potential (E°cell)for the reaction below is +1.10 V. The cell potential for this reaction is __________ V when the concentration of [Cu2+] = 1.0 × 10-5 M and [Zn2+] = 3.5 M. Zn (s)+ Cu2+ (aq)→ Cu (s)+ Zn2+ (aq)

Introduction: Matter and Measurement

Atoms, Molecules, and Ions

Stoichiometry: Calculations With Chemical Formulas and Equations

Aqueous Reactions and Solution Stoichiometry

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 sulfur in the HSO₄^- ion?

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

The standard cell potential (E°_cell)for the voltaic cell based on the reaction below is __________ V. Cr (s)+ 3Fe³⁺ (aq)→ 3Fe²⁺ (aq)+ Cr³⁺ (aq)

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 electrolysis of molten AlCl₃ for 3.25 hr with an electrical current of 15.0 A produces __________ g of aluminum metal.

How many seconds are required to produce 4.00 g of aluminum metal from the electrolysis of molten AlCl₃ with an electrical current of 12.0 A?

A voltaic cell is constructed with two silver-silver chloride electrodes, where the half-reaction is AgCl (s)+ e^- → Ag (s)+ Cl^- (aq)E° = +0.222 V The concentrations of chloride ion in the two compartments are 0.0222 M and 2.22 M, respectively. The cell emf is __________ V.

The more __________ the value of E°_red, the greater the driving force for reduction.

Which substance is the oxidizing agent in the reaction below? Pb + PbO₂ + 2H₂SO₄ → 2PbSO₄ + 2H₂O

The standard cell potential (E°_cell)for the reaction below is +1.10 V. The cell potential for this reaction is __________ V when the concentration of [Cu²⁺] = 1.0 × 10^-5 M and [Zn²⁺] = 3.5 M. Zn (s)+ Cu²⁺ (aq)→ Cu (s)+ Zn²⁺ (aq)