Chapter 17 - Electrochemistry

Questão 1 de 38

1

What is the oxidation number of bromine in the BrO3- ion?

Selecione uma das seguintes:

A) -1
B) +1
C) +3
D) +5
E) +7

Explicação

Questão 2 de 38

1

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

Selecione uma das seguintes:

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

Explicação

Questão 3 de 38

1

Which element is oxidized in the reaction below?

Fe(CO)5 (l) + 2HI (g) → Fe(CO)4I2 (s) + CO (g) + H2 (g)

Selecione uma das seguintes:

A) Fe
B) C
C) O
D) H
E) I

Explicação

Questão 4 de 38

1

Which element is reduced in the reaction below?

Fe(CO)5 (l) + 2HI (g) → Fe(CO)4I2 (s) + CO (g) + H2 (g)

Selecione uma das seguintes:

A) Fe
B) C
C) O
D) H
E) I

Explicação

Questão 5 de 38

1

Which of the following reactions is a redox reaction?

(a) K2CrO4 + BaCl2 → BaCrO4 + 2KCl
(b) Pb22+ + 2Br- → PbBr
(c) Cu + S → CuS

Selecione uma das seguintes:

A) (a) only
B) (b) only
C) (c) only
D) (a) and (c)
E) (b) and (c)

Explicação

Questão 6 de 38

1

Which one of the following reactions is a redox reaction?

Selecione uma das seguintes:

A) NaOH + HCl → NaCl + H2O
B) Pb2+ + 2Cl- → PbCl2
C) AgNO3 + HCl → HNO3 + AgCl
D) None of the above is a redox reaction.

Explicação

Questão 7 de 38

1

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

Selecione uma das seguintes:

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

Explicação

Questão 8 de 38

1

What is the coefficient of the permanganate ion when the following equation is balanced?
MnO4- + Br- → Mn2+ + Br2 (acidic solution)

Selecione uma das seguintes:

A) 1
B) 2
C) 3
D) 5
E) 4

Explicação

Questão 9 de 38

1

What is the coefficient of Fe3+ when the following equation is balanced?
CN- + Fe3+ → CNO- + Fe2+ (basic solution)

Selecione uma das seguintes:

A) 1
B) 2
C) 3
D) 4
E) 5

Explicação

Questão 10 de 38

1

The purpose of the salt bridge in an electrochemical cell is to __________.

Selecione uma das seguintes:

A) maintain electrical neutrality in the half-cells via migration of ions.
B) provide a source of ions to react at the anode and cathode.
C) provide oxygen to facilitate oxidation at the anode.
D) provide a means for electrons to travel from the anode to the cathode.
E) provide a means for electrons to travel from the cathode to the anode.

Explicação

Questão 11 de 38

1

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

Selecione uma das seguintes:

A) NO → NO3-
B) CO2 → Cr2O42-
C) VO2+ → VO2+
D) H2AsO4 → H3AsO3
E) O2 → H2O2

Explicação

Questão 12 de 38

1

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

Selecione uma das seguintes:

A) MnO2 → MnO4-
B) Br2 → BrO3-
C) NO → HNO2
D) HSO4- → H2SO3
E) Mn2+ → MnO4-

Explicação

Questão 13 de 38

1

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

Selecione uma das seguintes:

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

Explicação

Questão 14 de 38

1

Which one of the following types of elements is most likely to be a good oxidizing agent?

Selecione uma das seguintes:

A) alkali metals
B) lanthanides
C) alkaline earth elements
D) transition elements
E) halogens

Explicação

Questão 15 de 38

1

Which one of the following is the best oxidizing agent?

Selecione uma das seguintes:

A) H2
B) Na
C) O2
D) Li
E) Ca

Explicação

Questão 16 de 38

1

Which of the following reactions will occur spontaneously as written?

Selecione uma das seguintes:

A) Sn4+ (aq) + Fe3+ (aq) → Sn2+ (aq) + Fe2+ (aq)
B) 3Fe (s) + 2Cr3+ (aq) → 2Cr (s) + 3Fe2+ (aq)
C) Sn4+ (aq) + Fe2+ (aq) → Sn2+ (aq) + Fe (s) ← I chose this one
D) 3Sn4+ (aq) + 2Cr (s) → 2Cr3+ (aq) + 3Sn2+ (aq)
E) 3Fe2+ (aq) → Fe (s) + 2Fe3+ (aq)

Explicação

Questão 17 de 38

1

Consider an electrochemical cell based on the reaction:

2H+ (aq) + Sn (s) → Sn2+ (aq) + H2 (g)

Which of the following actions would change the measured cell potential?

Selecione uma das seguintes:

A) increasing the pH in the cathode compartment
B) lowering the pH in the cathode compartment
C) increasing the [Sn2+] in the anode compartment
D) increasing the pressure of hydrogen gas in the cathode compartment
E) Any of the above will change the measure cell potential.

Explicação

Questão 18 de 38

1

Consider an electrochemical cell based on the reaction:

2H+ (aq) + Sn (s) → Sn2+ (aq) + H2 (g)

Which of the following actions would not change the measured cell potential?

Selecione uma das seguintes:

A) lowering the pH in the cathode compartment
B) addition of more tin metal to the anode compartment
C) increasing the tin (II) ion concentration in the anode compartment
D) increasing the pressure of hydrogen gas in the cathode compartment
E) Any of the above will change the measured cell potential.

Explicação

Questão 19 de 38

1

Cathodic protection of a metal pipe against corrosion usually entails

Selecione uma das seguintes:

A) attaching an active metal to make the pipe the anode in an electrochemical cell.
B) coating the pipe with another metal whose standard reduction potential is less negative than that of the pipe.
C) attaching an active metal to make the pipe the cathode in an electrochemical cell.
D) attaching a dry cell to reduce any metal ions which might be formed.
E) coating the pipe with a fluoropolymer to act as a source of fluoride ion (since the latter is so hard to oxidize).

Explicação

Questão 20 de 38

1

One of the differences between a voltaic cell and an electrolytic cell is that in an electrolytic cell __________.

Selecione uma das seguintes:

A) an electric current is produced by a chemical reaction
B) electrons flow toward the anode
C) a nonspontaneous reaction is forced to occur
D) O2 gas is produced at the cathode
E) oxidation occurs at the cathode

Explicação

Questão 21 de 38

1

__________ is reduced in the following reaction:

Cr2O72- + 6S2O32- + 14H+ → 2Cr3+ + 3S4O62- + 7H2O

Selecione uma das seguintes:

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

Explicação

Questão 22 de 38

1

Which substance is serving as the oxidizing agent in the following reaction?

14H+ + Cr2O72- + 3Ni → 3Ni2+ + 2Cr3+ + 7H2O

Selecione uma das seguintes:

A) Ni
B) H+
C) Cr2O72-
D) H2O
E) Ni2+

Explicação

Questão 23 de 38

1

__________ electrons appear in the following half-reaction when it is balanced.

S4O62- → S2O32-

Selecione uma das seguintes:

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

Explicação

Questão 24 de 38

1

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

Selecione uma das seguintes:

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

Explicação

Questão 25 de 38

1

The electrode at which oxidation occurs is called the __________.

Selecione uma das seguintes:

A) oxidizing agent
B) cathode
C) reducing agent
D) anode
E) voltaic cell

Explicação

Questão 26 de 38

1

In a voltaic cell, electrons flow from the to the .

Selecione uma das seguintes:

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

Explicação

Questão 27 de 38

1

The standard cell potential (E°cell) for the voltaic cell based on the reaction below is __________ V.
Sn2+ (aq) + 2Fe3+ (aq) → 2Fe2+ (aq) + Sn4+ (aq)

Selecione uma das seguintes:

A) +0.46
B) +0.617
C) +1.39
D) -0.46
E) +1.21

Explicação

Questão 28 de 38

1

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)

Selecione uma das seguintes:

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

Explicação

Questão 29 de 38

1

The standard cell potential (E°cell) of the reaction below is +0.126 V. The value of ΔG° for the reaction is __________ kJ/mol.

Pb (s) + 2H+ (aq) → Pb2+ (aq) + H2 (g)

Selecione uma das seguintes:

A) -24.3
B) +24.3
C) -12.6
D) +12.6
E) -50.8

Explicação

Questão 30 de 38

1

The standard cell potential (E°cell) of the reaction below is -0.34 V. The value of ΔG° for the reaction is __________ kJ/mol.

Cu (s) + 2H+ (aq) → Cu2+ (aq) + H2 (g)

Selecione uma das seguintes:

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

Explicação

Questão 31 de 38

1

The standard cell potential (E°cell) of the reaction below is +1.34 V. The value of ΔG° for the reaction is __________ kJ/mol.

3Cu (s) + 2MnO4- (aq) + 8H+ (aq) → 3Cu2+ (aq) + 2MnO2 (s) + 4H2O (l)

Selecione uma das seguintes:

A) -24.3
B) +259
C) -259
D) +776
E) none of the above

Explicação

Questão 32 de 38

1

Galvanized iron is iron coated with __________.

Selecione uma das seguintes:

A) magnesium.
B) zinc.
C) chromium.
D) phosphate.
E) iron oxide.

Explicação

Questão 33 de 38

1

The standard cell potential (E°) of a voltaic cell constructed using the cell reaction below is 0.76 V:

Zn (s) + 2H+ (aq) → Zn2+ (aq) + H2 (g)

With PH2 = 1.0 atm and [Zn2+] = 1.0 M, the cell potential is 0.66 V. The concentration of H+ in the cathode compartment is __________ M.

Selecione uma das seguintes:

A) 2.0 × 10-2
B) 4.2 × 10-4
C) 1.4 × 10-1
D) 4.9 × 101
E) 1.0 × 10-12

Explicação

Questão 34 de 38

1

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.

Selecione uma das seguintes:

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

Explicação

Questão 35 de 38

1

The standard cell potential (E°cell) for the reaction below is +0.63 V. The cell potential for this reaction is __________ V when [Zn2+] = 3.5 M and [Pb2+] = 2.0 × 10-4 M.

Pb2+ (aq) + Zn (s) → Zn2+ (aq) + Pb (s)

Selecione uma das seguintes:

A) 0.50
B) 0.84
C) 0.39
D) 0.76
E) 0.63

Explicação

Questão 36 de 38

1

The standard emf for the cell using the overall cell reaction below is +2.20 V:

2Al (s) + 3I2 (s) → 2Al3+ (aq) + 6I- (aq)

The emf generated by the cell when [Al3+] = 4.5 × 10-3 M and [I-] = 0.15 M is ________ V.

Selecione uma das seguintes:

A) 2.20
B) 2.32
C) 2.10
D) 2.39
E) 2.23

Explicação

Questão 37 de 38

1

The most difficult species to reduce and the poorest oxidizing agent is __________.

Selecione uma das seguintes:

A) Fr+
B) F-
C) Li+
D) He

Explicação

Questão 38 de 38

1

In a half reaction the amount of a substance that is reduced or oxidized is directly proportional to the number of electrons generated in the cell.

Selecione uma das seguintes:

True
False

	Criado por Dawn G aproximadamente 9 anos atrás

Originally chapter 20

Chapter 17 - Electrochemistry

Chapter 17 - Electrochemistry

Questão 1 de 38

What is the oxidation number of bromine in the BrO3- ion?

Selecione uma das seguintes:

Explicação

Questão 2 de 38

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

Selecione uma das seguintes:

Explicação

Questão 3 de 38

Which element is oxidized in the reaction below? Fe(CO)5 (l) + 2HI (g) → Fe(CO)4I2 (s) + CO (g) + H2 (g)

Selecione uma das seguintes:

Explicação

Questão 4 de 38

Which element is reduced in the reaction below? Fe(CO)5 (l) + 2HI (g) → Fe(CO)4I2 (s) + CO (g) + H2 (g)

Selecione uma das seguintes:

Explicação

Questão 5 de 38

Which of the following reactions is a redox reaction? (a) K2CrO4 + BaCl2 → BaCrO4 + 2KCl (b) Pb22+ + 2Br- → PbBr (c) Cu + S → CuS

Selecione uma das seguintes:

Explicação

Questão 6 de 38

Which one of the following reactions is a redox reaction?

Selecione uma das seguintes:

Explicação

Questão 7 de 38

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

Selecione uma das seguintes:

Explicação

Questão 8 de 38

What is the coefficient of the permanganate ion when the following equation is balanced? MnO4- + Br- → Mn2+ + Br2 (acidic solution)

Selecione uma das seguintes:

Explicação

Questão 9 de 38

What is the coefficient of Fe3+ when the following equation is balanced? CN- + Fe3+ → CNO- + Fe2+ (basic solution)

Selecione uma das seguintes:

Explicação

Questão 10 de 38

The purpose of the salt bridge in an electrochemical cell is to __________.

Selecione uma das seguintes:

Explicação

Questão 11 de 38

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

Selecione uma das seguintes:

Explicação

Questão 12 de 38

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

Selecione uma das seguintes:

Explicação

Questão 13 de 38

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

Selecione uma das seguintes:

Explicação

Questão 14 de 38

Which one of the following types of elements is most likely to be a good oxidizing agent?

Selecione uma das seguintes:

Explicação

Questão 15 de 38

Which one of the following is the best oxidizing agent?

Selecione uma das seguintes:

Explicação

Questão 16 de 38

Which of the following reactions will occur spontaneously as written?

Selecione uma das seguintes:

Explicação

Questão 17 de 38

Consider an electrochemical cell based on the reaction: 2H+ (aq) + Sn (s) → Sn2+ (aq) + H2 (g) Which of the following actions would change the measured cell potential?

Selecione uma das seguintes:

Explicação

Questão 18 de 38

Consider an electrochemical cell based on the reaction: 2H+ (aq) + Sn (s) → Sn2+ (aq) + H2 (g) Which of the following actions would not change the measured cell potential?

Selecione uma das seguintes:

Explicação

Questão 19 de 38

Cathodic protection of a metal pipe against corrosion usually entails

Selecione uma das seguintes:

Explicação

Questão 20 de 38

Which element is oxidized in the reaction below?

Fe(CO)5 (l) + 2HI (g) → Fe(CO)4I2 (s) + CO (g) + H2 (g)

Which element is reduced in the reaction below?

Fe(CO)5 (l) + 2HI (g) → Fe(CO)4I2 (s) + CO (g) + H2 (g)

Which of the following reactions is a redox reaction?

(a) K2CrO4 + BaCl2 → BaCrO4 + 2KCl
(b) Pb22+ + 2Br- → PbBr
(c) Cu + S → CuS

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

What is the coefficient of the permanganate ion when the following equation is balanced?
MnO4- + Br- → Mn2+ + Br2 (acidic solution)

What is the coefficient of Fe3+ when the following equation is balanced?
CN- + Fe3+ → CNO- + Fe2+ (basic solution)

Consider an electrochemical cell based on the reaction:

2H+ (aq) + Sn (s) → Sn2+ (aq) + H2 (g)

Which of the following actions would change the measured cell potential?

Consider an electrochemical cell based on the reaction:

2H+ (aq) + Sn (s) → Sn2+ (aq) + H2 (g)

Which of the following actions would not change the measured cell potential?

__________ is reduced in the following reaction:

Cr2O72- + 6S2O32- + 14H+ → 2Cr3+ + 3S4O62- + 7H2O

Which substance is serving as the oxidizing agent in the following reaction?

14H+ + Cr2O72- + 3Ni → 3Ni2+ + 2Cr3+ + 7H2O

__________ electrons appear in the following half-reaction when it is balanced.

S4O62- → S2O32-

In a voltaic cell, electrons flow from the to the .

The standard cell potential (E°cell) for the voltaic cell based on the reaction below is __________ V.
Sn2+ (aq) + 2Fe3+ (aq) → 2Fe2+ (aq) + Sn4+ (aq)

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) of the reaction below is +0.126 V. The value of ΔG° for the reaction is __________ kJ/mol.

Pb (s) + 2H+ (aq) → Pb2+ (aq) + H2 (g)

The standard cell potential (E°cell) of the reaction below is -0.34 V. The value of ΔG° for the reaction is __________ kJ/mol.

Cu (s) + 2H+ (aq) → Cu2+ (aq) + H2 (g)

The standard cell potential (E°cell) of the reaction below is +1.34 V. The value of ΔG° for the reaction is __________ kJ/mol.

3Cu (s) + 2MnO4- (aq) + 8H+ (aq) → 3Cu2+ (aq) + 2MnO2 (s) + 4H2O (l)

The standard cell potential (E°) of a voltaic cell constructed using the cell reaction below is 0.76 V:

Zn (s) + 2H+ (aq) → Zn2+ (aq) + H2 (g)

With PH2 = 1.0 atm and [Zn2+] = 1.0 M, the cell potential is 0.66 V. The concentration of H+ in the cathode compartment is __________ M.

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 standard cell potential (E°cell) for the reaction below is +0.63 V. The cell potential for this reaction is __________ V when [Zn2+] = 3.5 M and [Pb2+] = 2.0 × 10-4 M.

Pb2+ (aq) + Zn (s) → Zn2+ (aq) + Pb (s)

The standard emf for the cell using the overall cell reaction below is +2.20 V:

2Al (s) + 3I2 (s) → 2Al3+ (aq) + 6I- (aq)

The emf generated by the cell when [Al3+] = 4.5 × 10-3 M and [I-] = 0.15 M is ________ V.