Deck 13: Electrochemistry

Question 1

Electrolysis can be used to electroplate metals onto surfaces.

Answer 1

True

Question 2

A positive voltage in the standard reduction potential means that the half-reaction proceeds as a reduction when connected to the standard hydrogen electrode (SHE)because the SHE is serving as the anode .

Answer 2

True

Question 3

Galvanic corrosion occurs only when two different metals contact each other in the presence of an appropriate electrolyte.

Answer 3

True

Question 4

If a chemical species gains electrons in a redox reaction, the species is said to have undergone oxidation.

Question 5

Which of the following species undergoes oxidation in the formation of iron (III)oxide?

A)FeO
B)Fe₂O₃
C)Fe
D)O₂

Question 6

Consider the following reaction: Cu → Cu ²⁺ + 2e ^-
Which of the following best describes the reaction?

A)Oxidation half-reaction
B)Reduction half-reaction
C)Hydrolysis
D)Excitation

Question 7

If an electrochemical half-reaction includes the production or consumption of a gas, the standard state is a pressure of 1 atm.

Question 8

In the context of electrolysis, if the electrodes are chemically inert materials that simply provide a path for electrons, the process is called active electrolysis.

Question 9

All dry cell batteries are rechargeable.

Question 10

Consider the following reaction: Na⁺+ e ⁻ → Na
Which of the following best describes the reaction?

A)Oxidation half-reaction
B)Reduction half-reaction
C)Ionization
D)Dissociation

Question 11

The species undergoing reduction is referred to as an oxidizing agent.

Question 12

A galvanic cell is an electrochemical cell in which a spontaneous chemical reaction can be used to generate an electrical current.

Question 13

Reduction occurs at the anode of a galvanic cell.

Question 14

Which of the following species undergoes reduction in the formation of iron (III)oxide?

A)FeO
B)Fe₂O₃
C)Fe
D)O₂

Question 15

The rusting of automobile bodies is an example of uniform corrosion.

Question 16

Secondary cells are rechargeable.

Question 17

The standard hydrogen electrode (SHE)involves a platinum wire or foil that is the conducting source of electrons; hydrogen gas is bubbled over the electrode at a pressure of 1 atm, and the electrolyte solution is 1 M HCl(aq).

Question 18

Electrolysis involves using an external electric current to drive an electrochemical reaction in a nonspontaneous direction.

Question 19

The Nernst equation describes the pH required for a spontaneous electrolytic reaction.

Question 20

Identify a true statement about a redox reaction.

A)It involves a transfer of protons from one species to another.
B)It creates electrons.
C)It involves a transfer of electrons between two species.
D)It is always nonspontaneous.

Question 21

The rusting of the sheet metal of a car is an example of:

A)uniform corrosion.
B)galvanic corrosion.
C)electrolysis.
D)galvanized steel.

Question 22

By convention, the standard hydrogen electrode (SHE)is assigned a voltage of _____ V .

A)− 1.000
B)1.000
C)0.150
D)0.000

Question 23

What is the cell potential (E⁰) f or a galvanic cell formed from the following two half-reactions? Assume that the cell temperature is 38°C and the operating pressure is 0.04 atm.

A)1.90 V
B)1.95 V
C)1.99 V
D)2.20 V

Question 24

What is the cell potential (E ⁰ )for a galvanic cell formed from the following two half- reactions ?

A)−1 .43 V
B)+1.43 V
C)−0 .93 V
D)+0.93 V

Question 25

A salt bridge between half-reactions maintains the electrical balance of a galvanic cell. This bridge is filled with:

A)a strong electrolyte.
B)inert carbon.
C)a weak electrolyte.
D)inert helium.

Question 26

In the following galvanic cell: , the right-hand side of this notation represents the:

A)spontaneous half of the reaction.
B)oxidation half-reaction.
C)anode of the cell.
D)reduction half-reaction.

Question 27

Suppose that you have an iron rod that requires copper coating. You have calculated that you need to deposit 4.00 g of copper to achieve an adequate coating. If your electrolysis cell (using Cu ²⁺)runs at 1.5 A, how long must you operate the cell to obtain the desired coating?

A)1 hour and 12 minutes
B)2 hours and 15 minutes
C)3 hours and 22 minutes
D)4 hours and 35 minutes

Question 28

What is the cell potential (E ⁰ )for a galvanic cell formed from the following two half- reactions?

A)+1.334 V
B)− 2.046 V
C)+2.046 V
D)+2.758 V

Question 29

How many grams of silver are deposited at a platinum cathode in the electrolysis of AgNO ₃ (aq)by 5.30 A of electric current in 4.0 hours?

A)85.3 g
B)42.6 g
C)121 g
D)188 g

Question 30

In the context of cell notations in galvanic cells, a phase boundary is denoted by _____.

A)|
B)||
C)-
D)=

Question 31

In a galvanic cell, oxidation occurs at _____.

A)the cathode
B)a salt bridge
C)the anode
D)the external circuit

Question 32

The most prevalent type of primary battery in use today is _____.

A)the rechargeable batter y
B)the lead-acid storage battery
C)the alkaline batter y
D)the nickel-metal-hydride battery

Question 33

Identify the balanced chemical equation for the following cell:

A)Al( s )+ Hg²⁺( aq )→ Al³⁺( aq )+ Hg( l )
B)2 Al( s )+ Hg²⁺( aq )→ 2 Al³⁺( aq )+ Hg( l )
C)Al( s )+ 3 Hg²⁺( aq )→ Al³⁺( aq )+ 3 Hg( l )
D)2 Al( s )+ 3 Hg²⁺( aq )→ 2 Al³⁺( aq )+ 3 Hg( l )

Question 34

In a galvanic cell, reduction occurs at _____.

A)the cathode
B)a salt bridge
C)the anode
D)the external circuit

Question 35

Which of the following cells is most likely to be an example of a galvanic cell?

A)Zn(s)| Zn ²⁺ || Cu ²⁺ | Cu(s)
B)Cu(s)| Cu ²⁺ || Fe ²⁺ | Fe(s)
C)Au(s)| Au ⁺ || Ag ⁺ | Ag(s)
D)Sn(s)| Sn ²⁺ || Fe ²⁺ | Fe(s)

Question 36

Balance the following electrochemical reaction in acid: MnO ₄ ⁻ ( aq )+ Zr( s )↔ Mn ²⁺( aq )+ Zr ²⁺( aq )

A)2 MnO₄ ⁻ ( aq )+ 16 H⁺( aq )+ 5 Zr( s )→ 2 Mn²⁺( aq )+ 5 Zr²⁺( aq )+ 8 H₂O( l )
B)2 MnO₄ ⁻ ( aq )+ 5 Zr( s ) → 2 Mn²⁺( aq )+ 5 Zr²⁺( aq )
C)MnO₄ ⁻ ( aq )+ Zr( s )→ Mn²⁺( aq )+ Zr²⁺( aq )+ 5 e ⁻
D)2 MnO₄ ⁻ ( aq )+ 8 H⁺( aq )+ 5 Zr( s )→ 2 Mn²⁺( aq )+ 5 Zr²⁺( aq )+ 8 H₂O( l )

Question 37

The most common fuel cells are based on the reaction of _____.

A)nickel and oxygen to produce nickel oxide
B)hydrogen and oxygen to produce water
C)lead and sulfuric acid to produce lead sulfate
D)zinc and air to produce zinc oxide

Question 38

What is the cell potential (E ⁰ )for a galvanic cell formed from the following two half- reactions?

A)− 2.31 V
B)+4.33 V
C)− 1.32 V
D)+2.00 V

Question 39

Single use, non-rechargeable batteries are referred to as _____.

A)primary cells
B)secondary cells
C)tertiary cells
D)electrolytic cells

Question 40

What is the cell potential (E⁰)for a galvanic cell formed from the following two half-reactions? Assume that the cell temperature is 45°C and the operating pressure is 0.06 atm.

A)1.03 V
B)1.12 V
C)1.24 V
D)0.36 V

Question 41

In the context of the cell notation of galvanic cells, the anode is always written on the right and the cathode on the left.

Question 42

Which of the following represents the Nernst equation?

A)
B)
C)
D)

Question 43

An electrolysis cell that deposits copper (from Cu ²⁺ ions)operates for 30 minutes at an electric current of 3.20 A. What mass of copper is deposited?

A)1.9 g
B)2.3 g
C)3.5 g
D)4.2 g

Question 44

In general, a secondary cell has a much shorter life cycle than a primary cell of the same capacity.

Question 45

In any galvanic cell, the half-reaction with the more positive reduction potential will be the cathode.