Question 1

How many grams of copper will be plated out by a current of 2.3 A applied for 35 minutes to a 0.50 M solution of copper (II)sulfate?

Accepted Answer

A) 1.6 
B) 3.2 
C) 1.8 × 10-2 
D) 3.6 × 10-2 
E) 0.019 
A) 1.6 
B) 3.2 
C) 1.8 × 10-2 
D) 3.6 × 10-2 
E) 0.019

Question 2

________ electrons appear in the following half-reaction when it is balanced. S4O62- → 2S2O32-

Accepted Answer

A) 6 
B) 2 
C) 4 
D) 1 
E) 3 
A) 6 
B) 2 
C) 4 
D) 1 
E) 3

Question 3

________ is oxidized in the following reaction: Cr2O72- + 6S2O32- + 14H+ → 2Cr3+ + 3S4O62- + 7H2O

Accepted Answer

A) Cr6+ 
B) S2+ 
C) H+ 
D) O2- 
E) S4O62- 
A) Cr6+ 
B) S2+ 
C) H+ 
D) O2- 
E) S4O62-

Question 4

When the cell potential is negative in a voltaic cell, the cell reaction will not proceed spontaneously.

Accepted Answer

A) True 
 B)False

Question 5

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 6

The gain of electrons by an element is called ________.

Accepted Answer

A) reduction 
B) oxidation 
C) disproportionation 
D) fractionation 
E) sublimation 
A) reduction 
B) oxidation 
C) disproportionation 
D) fractionation 
E) sublimation

Question 7

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

Accepted Answer

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

Question 8

The reduction half reaction occurring in the standard hydrogen electrode is ________.

Accepted Answer

A) H2 (g, 1 atm) → 2H+ (aq, 1M) + 2e- 
B) 2H+ (aq) + 2OH- → H2O (l) 
C) O2 (g) + 4H+ (aq)+ 4e- → 2H2O (l) 
D) 2H+ (aq, 1M) + 2e- → H2 (g, 1 atm) 
E) 2H+ (aq, 1M) + Cl2 (aq) → 2HCl (aq) 
A) H2 (g, 1 atm) → 2H+ (aq, 1M) + 2e- 
B) 2H+ (aq) + 2OH- → H2O (l) 
C) O2 (g) + 4H+ (aq)+ 4e- → 2H2O (l) 
D) 2H+ (aq, 1M) + 2e- → H2 (g, 1 atm) 
E) 2H+ (aq, 1M) + Cl2 (aq) → 2HCl (aq)

Question 9

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 10

What is the oxidation number of oxygen in H2O2?

Accepted Answer

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

Question 11

How many minutes will it take to plate out 16.22 g of Al metal from a solution of Al3+ using a current of 14.6 amps in an electrolytic cell?

Accepted Answer

A) 53.0 
B) 66.2 
C) 153 
D) 199 
E) 11900 
A) 53.0 
B) 66.2 
C) 153 
D) 199 
E) 11900

Question 12

What is the oxidation number of chromium in Cr2O72- ion?

Accepted Answer

A) +3 
B) +12 
C) +7 
D) +6 
E) +14 
A) +3 
B) +12 
C) +7 
D) +6 
E) +14

Question 13

Table 20.2  
-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 14

What is the oxidation number of phosphorous in the PH3 molecule?

Accepted Answer

A) -3 
B) -4 
C) -5 
D) +1 
E) 0 
A) -3 
B) -4 
C) -5 
D) +1 
E) 0

Question 15

The balanced half-reaction in which dichromate ion is reduced to chromium metal is a ________ process.

Accepted Answer

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

Question 16

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

Accepted Answer

KOH; potas

Question 17

In the electrochemical cell using the redox reaction below, the oxidation half reaction is ________. Sn4+ (aq) + Fe (s)→ Sn2+ (aq) + Fe2+ (aq)

Accepted Answer

A) Sn4+ + 2e-  → Sn2+ 
B) Fe → Fe2+  + 2e-  
C) Sn4+ → Sn2+  + 2e- 
D) Fe + 2e- → Fe2+ 
E) Fe + 2e- → Sn2+ 
A) Sn4+ + 2e-  → Sn2+ 
B) Fe → Fe2+  + 2e-  
C) Sn4+ → Sn2+  + 2e- 
D) Fe + 2e- → Fe2+ 
E) Fe + 2e- → Sn2+

Question 18

Calculate the number of grams of aluminum produced in 30.0 minutes by electrolysis of AlCl3 at a current of 12.0 A.

Accepted Answer

Question 19

The electrolysis of molten AlCl3 for 2.50 hr with an electrical current of 12.0 A produces ________ g of aluminum metal.

Accepted Answer

A) 90.7 
B) 0.373 
C) 2.80 × 10-3 
D) 10.1 
E) 30.2 
A) 90.7 
B) 0.373 
C) 2.80 × 10-3 
D) 10.1 
E) 30.2

Question 20

What is the oxidation number of nitrogen in the NH2OH molecule?

Accepted Answer

A) -1 
B) -2 
C) -3 
D) 0 
E) +1 
A) -1 
B) -2 
C) -3 
D) 0 
E) +1

Exam 20: Electrochemistry

How many grams of copper will be plated out by a current of 2.3 A applied for 35 minutes to a 0.50 M solution of copper (II)sulfate?

________ electrons appear in the following half-reaction when it is balanced. S4O62- → 2S2O32-

________ is oxidized in the following reaction: Cr2O72- + 6S2O32- + 14H+ → 2Cr3+ + 3S4O62- + 7H2O

When the cell potential is negative in a voltaic cell, the cell reaction will not proceed spontaneously.

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

The gain of electrons by an element is called ________.

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

The reduction half reaction occurring in the standard hydrogen electrode is ________.

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

What is the oxidation number of oxygen in H2O2?

How many minutes will it take to plate out 16.22 g of Al metal from a solution of Al3+ using a current of 14.6 amps in an electrolytic cell?

What is the oxidation number of chromium in Cr2O72- ion?

Table 20.2 -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)

What is the oxidation number of phosphorous in the PH3 molecule?

The balanced half-reaction in which dichromate ion is reduced to chromium metal is a ________ process.

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

In the electrochemical cell using the redox reaction below, the oxidation half reaction is ________. Sn4+ (aq) + Fe (s)→ Sn2+ (aq) + Fe2+ (aq)

Calculate the number of grams of aluminum produced in 30.0 minutes by electrolysis of AlCl3 at a current of 12.0 A.

The electrolysis of molten AlCl3 for 2.50 hr with an electrical current of 12.0 A produces ________ g of aluminum metal.

What is the oxidation number of nitrogen in the NH2OH molecule?

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

________ electrons appear in the following half-reaction when it is balanced. S₄O₆^2- → 2S₂O₃^2-

________ is oxidized in the following reaction: Cr₂O₇^2- + 6S₂O₃^2- + 14H⁺ → 2Cr³⁺ + 3S₄O₆^2- + 7H₂O

What is the oxidation number of oxygen in H₂O₂?

How many minutes will it take to plate out 16.22 g of Al metal from a solution of Al³⁺ using a current of 14.6 amps in an electrolytic cell?

What is the oxidation number of chromium in Cr₂O₇^2- ion?

Table 20.2 -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)

What is the oxidation number of phosphorous in the PH₃ molecule?

In the electrochemical cell using the redox reaction below, the oxidation half reaction is ________. Sn⁴⁺ (aq) + Fe (s)→ Sn²⁺ (aq) + Fe²⁺ (aq)

Calculate the number of grams of aluminum produced in 30.0 minutes by electrolysis of AlCl₃ at a current of 12.0 A.

The electrolysis of molten AlCl₃ for 2.50 hr with an electrical current of 12.0 A produces ________ g of aluminum metal.

What is the oxidation number of nitrogen in the NH₂OH molecule?