Deck 14: Oxidation-Reduction Reactions

Question 1

What is the oxidation number of carbon in carbon dioxide,CO₂?

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

Answer 1

+4

Question 2

Considering the following net ionic equation: Mg + Fe²⁺ $\rightarrow$ Mg²⁺ + Fe
The species REDUCED is _____,and the REDUCING AGENT is _____.

A) Mg; Mg
B) Mg; Fe²⁺
C) Fe²⁺; Fe²⁺
D) Fe²⁺; Mg

Answer 2

Fe²⁺; Mg

Question 3

Which example does NOT illustrate a redox reaction?

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

Answer 3

double displacement

Question 4

Which example illustrates a redox reaction?

A) metal and nonmetal
B) double displacement
C) neutralization
D) precipitation

Question 5

Given the accompanying partial activity series,which element CANNOT reduce nickel(II)to elemental nickel? Zn $\rightarrow$ Zn²⁺ + 2e^-
Fe $\rightarrow$ Fe²⁺ + 2e^-
Co $\rightarrow$ Co²⁺ + 2e^-
Ni $\rightarrow$ Ni²⁺ + 2e^-
Cu $\rightarrow$ Cu²⁺ + 2e^-

A) zinc
B) iron
C) cobalt
D) copper

Question 6

What is the oxidation number of sulfur in the thiosulfate ion,S₂O₃^2-?

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

Question 7

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

A) Zn
B) Fe²⁺
C) Ni
D) Cu²⁺

Question 8

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

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

Question 9

The major credit for creating the first "battery" goes to:

A) James Watt.
B) Andre Ampere.
C) Alessandro Volta.
D) Georg Ohm.

Question 10

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

A) Zn
B) Fe²⁺
C) Ni
D) Cu²⁺

Question 11

Considering the following net ionic equation: Mg + Fe²⁺ $\rightarrow$ Mg²⁺ + Fe
The species that is OXIDIZED is _____,and the OXIDIZING AGENT is _____.

A) Mg; Mg
B) Mg; Fe²⁺
C) Fe²⁺; Fe²⁺
D) Fe²⁺; Mg

Question 12

Which statement is FALSE?

A) Silver ion (Ag⁺)to silver atom is reduction.
B) Chloride (Cl^-)ion to chlorine atom is reduction.
C) Hydrogen atom to hydride ion (H^-)is reduction.
D) Sulfur atom to sulfide ion (S^2-)is reduction.

Question 13

What is the oxidation number of nitrogen in the nitrate ion,NO₃^-?

A) -1
B) -3
C) +6
D) +5

Question 14

Which statement is TRUE?

A) Hydrogen atom to hydrogen ion (H⁺)is reduction.
B) Oxygen atom to oxide ion (O^2-)is reduction.
C) Tin atom to tin(IV)ion is reduction.
D) Fluoride ion (F^-)to fluorine atom is reduction.

Question 15

Given the accompanying partial activity series,predict which reaction(s)will occur as written. Zn $\rightarrow$ Zn²⁺ + 2e^-
Fe $\rightarrow$ Fe²⁺ + 2e^-
Co $\rightarrow$ Co²⁺ + 2e^-
Ni $\rightarrow$ Ni²⁺ + 2e^-
Cu $\rightarrow$ Cu²⁺ + 2e^-

A) Zn + Fe²⁺ $\rightarrow$ Zn²⁺ + Fe
B) Fe + Ni²⁺ $\rightarrow$ Fe²⁺ + Ni
C) Co + Cu²⁺ $\rightarrow$ Cu + Co²⁺
D) Zn + Fe²⁺ $\rightarrow$ Zn²⁺ + Fe,Fe + Ni²⁺ $\rightarrow$ Fe²⁺ + Ni ,and Co + Cu²⁺ $\rightarrow$ Cu + Co²⁺
E) None of these reactions will occur as written.

Question 16

What is the oxidation number of sulfur in the sulfite ion,SO₃^2-?

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

Question 17

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

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

Question 18

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

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

Question 19

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

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

Question 20

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

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

Question 21

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 RIGHT side of the cell. Zn $\rightarrow$ Zn²⁺ + 2e^- Fe $\rightarrow$ Fe²⁺ + 2e^-
Co $\rightarrow$ Co²⁺ + 2e^-
Ni $\rightarrow$ Ni²⁺ + 2e^-
Cu $\rightarrow$ Cu²⁺ + 2e^-

A) Fe $\rightarrow$ Fe²⁺ + 2e^-
B) Ni $\rightarrow$ Ni²⁺ + 2e^-
C) Fe²⁺ + 2e^- $\rightarrow$ Fe
D) Ni²⁺ + 2e^- $\rightarrow$ Ni

Question 22

Given the accompanying partial activity series,which element(s)will react with acid? Zn $\rightarrow$ Zn²⁺ + 2e^-
Fe $\rightarrow$ Fe²⁺ + 2e^-
Ni $\rightarrow$ Ni²⁺ + 2e^-
H₂ $\rightarrow$ 2H⁺ + 2e^-
Cu $\rightarrow$ Cu²⁺ + 2e^-
Ag $\rightarrow$ Ag⁺ + e^-

A) iron
B) nickel
C) zinc
D) iron,nickel,and zinc
E) None of these elements will react with acid.

Question 23

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 $\rightarrow$ Zn²⁺ + 2e^-
Fe $\rightarrow$ Fe²⁺ + 2e^-
Co $\rightarrow$ Co²⁺ + 2e^-
Ni $\rightarrow$ Ni²⁺ + 2e^-
Cu $\rightarrow$ Cu²⁺ + 2e^-

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 24

Which example BEST represents the reaction between magnesium and hydrochloric acid?

A) Mg + 2 HCl $\rightarrow$ MgCl₂ + H₂
B) Mg + 2 HCl $\rightarrow$ MgH₂ + Cl₂
C) Mg + H₂Cl $\rightarrow$ MgCl + H₂
D) Magnesium and hydrochloric acid do not react.

Question 25

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

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

Question 26

Which example BEST represents the reaction between copper and hydrochloric acid?

A) Cu + 2 HCl $\rightarrow$ CuCl₂ + H₂
B) Cu + 2 HCl $\rightarrow$ CuH₂ + Cl₂
C) Cu + H₂Cl $\rightarrow$ CuCl + H₂
D) Copper and hydrochloric acid do not react.

Question 27

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

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

Question 28

If the accompanying drawing of an electrochemical cell represents an iron-nickel cell,use the partial activity series included to determine the component labeled 1. Zn $\rightarrow$ Zn²⁺ + 2e^- Fe $\rightarrow$ Fe²⁺ + 2e^-
Co $\rightarrow$ Co²⁺ + 2e^-
Ni $\rightarrow$ Ni²⁺ + 2e^-
Cu $\rightarrow$ Cu²⁺ + 2e^-

A) iron anode
B) nickel anode
C) iron cathode
D) nickel cathode

Question 29

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 $\rightarrow$ Zn²⁺ + 2e^- Fe $\rightarrow$ Fe²⁺ + 2e^-
Co $\rightarrow$ Co²⁺ + 2e^-
Ni $\rightarrow$ Ni²⁺ + 2e^-
Cu $\rightarrow$ Cu²⁺ + 2e^-

A) Fe $\rightarrow$ Fe²⁺ + 2e^-
B) Ni $\rightarrow$ Ni²⁺ + 2e^-
C) Fe²⁺ + 2e^- $\rightarrow$ Fe
D) Ni²⁺ + 2e^- $\rightarrow$ Ni

Question 30

Which example represents the oxidation half-reaction for cobalt/cobalt(II)?

A) Co $\rightarrow$ Co²⁺ + 2 e^-
B) Co + 2 e^- $\rightarrow$ Co^2-
C) Co²⁺ + 2 e^- $\rightarrow$ Co
D) Co²⁺ $\rightarrow$ Co + 2 e^-

Question 31

If the accompanying drawing of an electrochemical cell represents an iron-nickel cell,use the partial activity series included to describe the component labeled 2. Zn $\rightarrow$ Zn²⁺ + 2e^- Fe $\rightarrow$ Fe²⁺ + 2e^-
Co $\rightarrow$ Co²⁺ + 2e^-
Ni $\rightarrow$ Ni²⁺ + 2e^-
Cu $\rightarrow$ Cu²⁺ + 2e^-

A) iron anode
B) nickel anode
C) iron cathode
D) nickel cathode

Question 32

Which example represents the reduction half-reaction for cobalt/cobalt(II)?

A) Co $\rightarrow$ Co²⁺ + 2 e^-
B) Co + 2 e^- $\rightarrow$ Co^2-
C) Co²⁺ + 2 e^- $\rightarrow$ Co
D) Co²⁺ $\rightarrow$ Co + 2 e^-

Question 33

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

A) Zn²⁺ + 2 e^- $\rightarrow$ Zn.
B) Zn $\rightarrow$ Zn²⁺ + 2 e^-.
C) H₂ $\rightarrow$ 2 H⁺ + 2 e^-.
D) 2 H⁺ + 2 e^- $\rightarrow$ H₂.

Question 34

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

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

Question 35

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

A) Zn²⁺ + 2 e^- $\rightarrow$ Zn.
B) Zn $\rightarrow$ Zn²⁺ + 2 e^-.
C) H₂ $\rightarrow$ 2 H⁺ + 2 e^-.
D) 2 H⁺ + 2 e^- $\rightarrow$ H₂.

Question 36

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 $\rightarrow$ Zn²⁺ + 2e^- Fe $\rightarrow$ Fe²⁺ + 2e^-
Co $\rightarrow$ Co²⁺ + 2e^-
Ni $\rightarrow$ Ni²⁺ + 2e^-
Cu $\rightarrow$ Cu²⁺ + 2e^-

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 37

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

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

Question 38

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

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

Question 39

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

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

Question 40

Given the accompanying partial activity series,which element(s)will react with acid? Zn $\rightarrow$ Zn²⁺ + 2e^-
Fe $\rightarrow$ Fe²⁺ + 2e^-
Ni $\rightarrow$ Ni²⁺ + 2e^-
H₂ $\rightarrow$ 2H⁺ + 2e^-
Cu $\rightarrow$ Cu²⁺ + 2e^-
Ag $\rightarrow$ Ag⁺ + e^-

A) nickel
B) copper
C) silver
D) nickel,copper,and silver
E) None of these elements will react with acid.

Question 41

What are the coefficients of the balanced equation that represents the reaction in a magnesium/chromium electrochemical cell? Mg (s)+ Cr³⁺ (aq) $\rightarrow$ Cr (s)+ Mg²⁺ (aq)

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

Question 42

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

A) reduction: Ag⁺ + e^- $\rightarrow$ Ag; oxidation: Ag $\rightarrow$ Ag⁺ + e^-
B) reduction: Ag $\rightarrow$ Ag⁺ + e^-; oxidation: Ag⁺ + e^- $\rightarrow$ Ag
C) reduction: Fe²⁺ + 2 e^- $\rightarrow$ Fe; oxidation: Fe $\rightarrow$ Fe²⁺ + 2 e^-
D) reduction: Fe $\rightarrow$ Fe²⁺ + 2 e^-; oxidation: Fe²⁺ + 2 e^- $\rightarrow$ Fe

Question 43

Write the balanced net ionic equation for the reaction consisting of the two half-reactions given. Mg $\rightarrow$ Mg²⁺ + 2 e^-
Pb⁴⁺ + 4 e^- $\rightarrow$ Pb

A) Pb (s)+ Mg²⁺ (aq) $\rightarrow$ Pb⁴⁺ (aq)+ Mg (s)
B) Mg (s)+ Pb⁴⁺ (aq) $\rightarrow$ Pb (s)+ Mg²⁺ (aq)
C) 2 Mg (s)+ Pb⁴⁺ (aq) $\rightarrow$ Pb (s)+ 2 Mg²⁺ (aq)
D) Pb (s)+ 2 Mg²⁺ (aq) $\rightarrow$ Pb⁴⁺ (aq)+ 2 Mg (s)

Question 44

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

A) Fe (s)+ Co²⁺ (aq) $\rightarrow$ Fe²⁺ (aq)+ Co (s)
B) Zn (s)+ Ni²⁺ (aq) $\rightarrow$ Zn²⁺ (aq)+ Ni (s)
C) Cu (s)+ Fe²⁺ (aq) $\rightarrow$ Cu²⁺ (aq)+ Fe (s)
D) Ni (s)+ Cu²⁺ (aq) $\rightarrow$ Ni²⁺ (aq)+ Cu (s)

Question 45

Given the following net ionic equation,select the correct pairing of half-reactions. Mg (s)+ Zn²⁺ (aq) $\rightarrow$ Mg²⁺ (aq)+ Zn (s)

A) reduction: Mg $\rightarrow$ Mg²⁺ + 2 e^-; oxidation: Zn²⁺ + 2 e^- $\rightarrow$ Zn
B) reduction: Zn²⁺ + 2 e^- $\rightarrow$ Zn; oxidation: Mg $\rightarrow$ Mg²⁺ + 2 e^-
C) reduction: Zn²⁺ + 2 e^- $\rightarrow$ Zn; oxidation: Mg²⁺ + 2 e^- $\rightarrow$ Mg
D) reduction: Zn $\rightarrow$ Zn²⁺ + 2 e^-; oxidation: Mg $\rightarrow$ Mg²⁺ + 2 e^-

Question 46

Which reaction could be used to electroplate nickel with gold?

A) Ni (s)+ 2 Au⁺ (aq) $\rightarrow$ Ni²⁺ (aq)+ 2 Au (s)
B) Zn (s)+ 2 Au⁺ (aq) $\rightarrow$ Zn²⁺ (aq)+ 2 Au (s)
C) 2 Au (s)+ Ni²⁺ (aq) $\rightarrow$ Ni (s)+ 2 Au⁺ (aq)
D) 2 Au (s)+ Zn²⁺ (aq) $\rightarrow$ Zn (s)+ 2 Au⁺ (aq)

Question 47

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

A) reduction: O₂ + 4 H⁺ + 4 e^- $\rightarrow$ 2H₂O; oxidation: H₂ $\rightarrow$ 2 H⁺ + 2 e^-
B) reduction: H₂ $\rightarrow$ 2 H⁺ + 2 e^-; oxidation: O₂ + 4 H⁺ + 4 e^- $\rightarrow$ 2 H₂O
C) reduction: O₂ + 4 H⁺ + 4 e^- $\rightarrow$ 2H₂O; oxidation: 2 H⁺ + 2 e^- $\rightarrow$ H₂
D) reduction: H₂ $\rightarrow$ 2 H⁺ + 2 e^-; oxidation: 2 H₂O $\rightarrow$ O₂ + 4H⁺ + 4 e^-

Question 48

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

A) Cu (s)+ Au³⁺ (aq) $\rightarrow$ Cu²⁺ (aq)+ Au (s)
B) 3 Cu (s)+ 2 Au³⁺ (aq) $\rightarrow$ 3 Cu²⁺ (aq)+ 2 Au (s)
C) 2 Au (s)+ 3 Cu²⁺ (aq) $\rightarrow$ 2 Au³⁺ (aq)+ 3 Cu (s)
D) Au (s)+ Cu²⁺ (aq) $\rightarrow$ Au³⁺ (aq)+ Cu (s)

Question 49

Given the following net ionic equation,select the CORRECT pairing of half-reactions. 2 Al (s)+ 3 Pb²⁺ (aq) $\rightarrow$ 2 Al³⁺ (aq)+ 3 Pb (s)

A) reduction: Al $\rightarrow$ Al³⁺ + 3 e^-; oxidation: Pb²⁺ + 2 e^- $\rightarrow$ Pb
B) reduction: Pb²⁺ + 2 e^- $\rightarrow$ Pb; oxidation: Al $\rightarrow$ Al³⁺ + 3 e^-
C) reduction: Al³⁺ + 3 e^- $\rightarrow$ Al; oxidation: Pb²⁺ + 2 e^- $\rightarrow$ Pb
D) reduction: Pb $\rightarrow$ Pb²⁺ + 2 e^-; oxidation: Al $\rightarrow$ Al³⁺ + 3 e^-

Question 50

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

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

Question 51

Write the balanced net ionic equation for the reaction consisting of the two half-reactions given. Cu $\rightarrow$ Cu²⁺ + 2 e^-
Ag⁺ + e^- $\rightarrow$ Ag

A) Cu (s)+ Ag⁺ (aq) $\rightarrow$ Cu²⁺ (aq)+ Ag (s)
B) Cu (s)+ 2 Ag⁺ (aq) $\rightarrow$ Cu²⁺ (aq)+ 2 Ag (s)
C) Ag (s)+ Cu²⁺ (aq) $\rightarrow$ Ag⁺ (aq)+ Cu (s)
D) 2 Ag (s)+ Cu²⁺ (aq) $\rightarrow$ 2 Ag⁺ (aq)+ Cu (s)

Question 52

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

A) Fe (s)+ Co²⁺ (aq) $\rightarrow$ Fe²⁺ (aq)+ Co (s)
B) Zn (s)+ Ni²⁺ (aq) $\rightarrow$ Zn²⁺ (aq)+ Ni (s)
C) Co (s)+ Fe²⁺ (aq) $\rightarrow$ Co²⁺ (aq)+ Fe (s)
D) Ni (s)+ Cu²⁺ (aq) $\rightarrow$ Ni²⁺ (aq)+ Cu (s)