Lesson 3: Electrochemistry And Corrosion Flashcards

1
Q
  1. In a bimetallic couple, the less noble material becomes the ______ and tends to corrode at an accelerated
    rate, compared with the uncoupled condition and the more noble material will act as the _______ in the
    corrosion cell.
    a. Cathode, anode
    b. Anode, cathode
    c. Anion, cation
    d. Cation, anion
A

B. Anode, cathode

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2
Q
  1. A conductive solution, like saltwater or even tap water, that allows the flow of ions between the anode and
    cathode.
    a. Solvent
    b. Electrons
    c. Reagents
    d. Electrolyte
A

D. Electrolyte

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3
Q
  1. It refers to corrosion damage induced when two dissimilar materials are coupled in a corrosive electrolyte.
    a. Electromagnetic corrosion
    b. thermal corrosion
    c. Galvanic corrosion
    d. Galvanic corrodent
A

c. Galvanic corrosion

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4
Q

Using the galvanic series table of some commercial metals and alloys in seawater, which among the following is properly arranged in a descending order based on their nobility?
a. Zinc, cadmium, platinum
b. Lead, tin, copper
c. Graphite, monel, lead
d. Gold, copper, platinum

A

c. Graphite, monel, lead

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5
Q
  1. The metal that is protected from corrosion. It receives electrons and undergoes reduction. MORE NOBLE
    a. Cathode
    b. Cation
    c. Anode
    d. Anion
A

A. Cathode

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6
Q
  1. Choose which statement is true
    a. The higher the electrode potential, the higher the tendency to gain electrons.
    b. The higher the electrode potential, the higher the tendency to lose electrons.
    c. The higher the electrode potential, the lower the tendency to lose electrons.
    d. The higher the electrode potential, the lower the tendency to gain electrons.
A

B. The higher the electrode potential, the higher the tendency to lose electrons.

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7
Q
  1. The standard electrode potential is measured at
    a. 1000 bar
    b. 760 mmHg
    c. 8000 Pa
    d. 3 atm
A

b. 760 mmHg

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8
Q
  1. Do electrons always flow from cathode to anode?
    a. Yes
    b. No
A

B. No

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9
Q
  1. The reduction potential value is positive when ___
    a. It is less electropositive than hydrogen
    b. It is more electropositive than hydrogen
    c. It is equal to the standard hydrogen electrode potential
    d. None of the above
A

a. It is less electropositive than hydrogen

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10
Q
  1. Which of the following describes the relationship between the zinc half cell and the copper half
    cell in an electrochemical cell?
    a. Zinc half cell gains electrons from the copper half cell, making zinc the cathode.
    b. Zinc half cell loses electrons to the copper half cell, making zinc the anode.
    c. Copper half cell gains electrons from the zinc half cell, making copper the anode.
    d. Copper half cell loses electrons to the zinc half cell, making copper the cathode
A

b. Zinc half cell loses electrons to the copper half cell, making zinc the anode.

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11
Q
  1. What is produced in an electrochemical cell while corrosion is occurring?
    a. Corrosion current
    b. Corrosion charge
    c. Corrosion rate
    d. None of the above
A

A. Corrosion current

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12
Q
  1. ____________ involves the transfer of electrons from the anode to the cathode.
    a. Chemical corrosion
    b. Electrochemical corrosion
    c. Electrochemistry
    d. None of the above
A

C. Electrochemistry

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13
Q
  1. 1 Faraday = _______________
    a. 1 coulomb
    b. 1000 coulomb
    c. 5000 coulomb
    d. 96500 coulomb
A

d. 96500 coulomb

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14
Q
  1. Electrochemical equivalent may be defined as the ____________ of the substance deposited by
    the passage of 1 coulomb of electricity.
    a. Volume
    b. Weight
    c. Density
    d. None of the above
A

B. Weight

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15
Q
  1. According to Faraday’s first law of electrolysis, the amount of any substance deposited at the
    electrode is directly proportional to the quantity of _______________
    a. Voltage drop
    b. Resistance
    c. Electricity passed
    d. Tolerance
A

c. Electricity passed

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16
Q
  1. Which kind of reaction occurs at anode?
    a. Oxidation
    b. Displacement
    c. Reduction
    d. Decomposition
A

A. Oxidation

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17
Q
  1. What is the name of the devices that are capable of converting chemical energy into electrical
    energy, or vice versa.
    a. Photochemical Cell
    b. Electric Cell
    c. Photoelectric Cell
    d. Electrochemical Cell
A

d. Electrochemical Cell

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18
Q
  1. Which electrode is denoted by a negative sign?
    a. Cathode
    b. Anode
    c. Diode
    d. None of these
A

B. Anode

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19
Q
  1. Corrosion can be prevented by?
    a. Tinning
    b. Alloying
    c. Galvanizing
    d. All of the Above
A

d. All of the Above

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20
Q
  1. The ions in a solution which conduct electricity are known as?
    a. Electrolytes
    b. Colloids
    c. Electrions
    d. Electrons
A

a. Electrolytes

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21
Q

These devices are capable of converting chemical energy into
electrical energy, or vice versa.

A

Electrochemical Cell

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22
Q

Classification of Electrochemical Cell

A

Galvanic cell
Electrolytic cell

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23
Q

Converts chem energy to electrical energy

A

Galvanic cell

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24
Q

Redox reax is spontaneous and responsible for the production of electrical energy

A

Galvanic cell

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25
Q

In galvanic cell, anode is ___ and cathode is ___

A

Negative
Positive

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26
Q

Move from anode to cathode

A

Galvanic cell

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27
Q

Oxidation: ___ of electrons
Reduction: ___ of electrons

A

Loss
Gain

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28
Q

Converts electrical energy to chem energy

A

Electrolytic cell

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29
Q

Redox reax is __ in Electrolytic cell and EE has to be ___ to initiate the reax

A

Not spontaneous
Supplied

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30
Q

Enter through the cathode and come through the anode

A

Electrolytic cell

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31
Q

____ also called “___” or wrongly
“electrolysis”) refers to corrosion damage induced when
two dissimilar materials are coupled in a corrosive
electrolyte.

A

Galvanic corrosion
dissimilar metal corrosion

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32
Q

In a bimetallic couple, the less noble material becomes the __ and tends to corrode at an accelerated rate

A

anode

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33
Q

more noble material will act as the __ in the corrosion cel

A

cathode

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34
Q

The metal that corrodes preferentially. It loses electrons and experiences oxidation. LESS NOBLE

A

Anode

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35
Q

The metal that is protected from corrosion. It receives electrons and undergoes reduction. MORE NOBLE

A

Cathode

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36
Q

___: A conductive solution, like saltwater or even tap
water, that allows the flow of ions between the anode and
cathode.

A

Electrolyte

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37
Q

Factors influencing galvanic corrosion

A

-The relative nobility of the metals
-Surface area ratio
-Electrolyte conductivity

38
Q

A __ difference in nobility leads to a
faster corrosion rate for the anode.

A

larger

39
Q

A larger anode area compared to the cathode area experiences a __ corrosion rate, and vice versa

A

slower

40
Q

___ conductivity allows for a greater flow of ions, accelerating the corrosion process.

A

Higher

41
Q

Preventing galvanic corrosion

A

Material selection
Electrical isolation
Coating
Sacrificial anodes

42
Q

It is the tendency for an electrode to lose or gain electrons when dipped
in the solution of its ions

A

Electrode potential

43
Q

Standard Electrode Potential is measured at

A

1 atm
298K
1M

44
Q

Electrode Potential Values

A

Positive
Negative

45
Q

__ is produced in an electrochemical cell while corrosion is occurring

A

Current

46
Q

__ involves the transfer of electrons from the anode to the cathode.

A

Electrochemical corrosion

47
Q

Speed at which any given metal deteriorates in a
specific environment.

A

Corrosion rate

48
Q

Corrosion rate is dependent on

A

Environmental Conditions
Type & Condition of Metal

49
Q

Electrochemical corrosion rate is “___”

A

instantaneous

50
Q

Discovered by Michael Faraday in the 19th Century

A

Faraday’s First Law of Electrolysis

51
Q

Faraday developed the __ known as
“FARADAY”

A

number of coulombs

52
Q

Charge of one mol of electron (6.022x10^23 electrons) will then be __

A

96,485 C.

53
Q

Charge on the electron is __ (Coulomb).

A

1.6x10^-19 C

54
Q

One mole of metal contains Avogadro’s number (___ ) of metal atoms.

A

6.022x10^23

55
Q

Faraday’s First Law of Electrolysis
This law states that:
Amount of substance produced at each electrode is _ to the
charge flowing through the cell.

A

directly proportional

56
Q

In faraday’s first law of electrolysis, z is a constant known as __ and characteristic of the substance deposited.

A

electro-chemical equivalent

57
Q

aka galvanic cell or voltaic cell

A

Electrochemical cell

58
Q

Galvanic cell is named after __

A

Luigi Galvani

59
Q

Components of electrochemical cells

A

Cathode
Anode
Electrolyres
Salt bridge

60
Q

Device used in Ecell for connecting its oxidation and reduction half cells wherein an inert electrolyte is used

A

Salt bridge

61
Q

Types of electrochemical cells

A

Dissimilar electrode cell
Concentration cell
Differential temperature cell

62
Q

These cells incolve diff types of metals or metal compositions coming into contact, leading to electron transfer between them

A

Dissimilar electrode cell

63
Q

2 types of concentration cells

A

Salt CC
Differential aeration cell

64
Q

Cells with 2 identical electrodes, each in contact with a soln of diff composition

A

Salt concentration cell

65
Q

Occurs due to differences in potential bet. differently aerated areas

A

Differential aeration cell

66
Q

Type of cell when 2 identical electrides are immersed in same elctrolytes but the electrodes are immersed into solution of two different temperatures

A

Differential temperature cell

67
Q

A list that describes the arrangement of elements in the order of their increasibf electrode potential values

A

Electrochemical series

68
Q

Orderly arrangement of the standard potentials for all metals

A

Emf series

69
Q

In emf series, the more __ the values, the more reactive the metals

A

Negative

70
Q

Galvanic cell is where ___ reaction occurs while electrolytic cell ____ reaction occurs

A

Spontaneous
Non spontaneous

71
Q

Determines the electrochemixal potential and nobility of metals (and metal alloys)

A

Galvanic series

72
Q

Ranking of metals and alloys according to their free corrosion potential in a given electrolyte

A

Galvanic series

73
Q

Galvanic corrosion or

A

Bimetallic corrosion

74
Q

The ___ a metal or an alloy is in the galvanic series, the less are the effects of galvanic corrosion compared to those metals ___.

A

Closer
Far apart

75
Q

Electrode potential is only negative. T or F.

A

F. Can either be + or -

76
Q

___ can be used to measure potential differences

A

Voltmeter

77
Q

Produced when electrons flow through anode to cathode

A

Current

78
Q

Half reaction of standard hydrogen electrode or SHE

A

2H+ (aq) + 2e- <—-> H2 (g)

79
Q

In SHE, why platinum is used

A
  1. Relatively inert, does not corrode easily
  2. Has catalytic qualities, promote proton reduction reaction
  3. Improve reaction kinetics
80
Q

Pure mercury is placed at the bottom of the tube, which is covered with a paste of mercury-mercurous cl (hg+hg2cl2)

A

Calomel reference electrode

81
Q

Pure Hg covers a Pt wire sealed thru the bottom of a glass tube

A

Calomel reference electrode

82
Q

Composed of a silver wire, sometimes coated witj a layer of solid silver chloride, immersed in a soln that is saturated with KCl and AgCl

A

Silver-silver chloride reference electrode

83
Q

Like the calomel electrode, the potential is more active the higher the KCl concentration

A

Silver-silver chloride reference electrode

84
Q

Consists of metallic copper immersed in saturated cu sulfate

A

Saturated cu-cu sulfate reference electrode

85
Q

Precision is slightly lower than calomel and AgCl electrodes but still sufficient for most corrosion studies

A

Saturated cu-cu sulfate reference electrode

86
Q

Speed at which any metal deteriorates

A

Corrosion rate

87
Q

A reduction current that occurs when electrons flow from electrode surface to a species in a soln

A

Cathodic current

88
Q

A oxidation current that occurs when electrons flow from electrode surface to a species in a soln

A

Anodic current

89
Q

Occurs when the electrolyte resistance is so high that the resultant current is not sufficient to appreciably polarize anodes and cathodes

A

Resistance control

90
Q

Can be calculated if the anode-cathode area ratio can be estimated

A

Corrosion current