Modified True/False
Indicate
whether the sentence or statement is true or false. If false,
change the identified word or phrase to make the sentence or statement
true.
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1. |
Reduction refers to the loss of electrons. ____________________
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2. |
The
oxidation number of an element increases as the element is oxidized.
____________________
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3. |
Metals at the top of the activity series are more reactive
than metals below them. ____________________
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4. |
According to the activity series, both nickel and zinc should
react with hydrochloric acid. ____________________
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5. |
In
a galvanic cell, oxidation occurs at the cathode. ____________________
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6. |
The
cell potential measures the amount of current that is flowing in
a galvanic cell. ________________________________________
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7. |
The
three minimum requirements for a galvanic cell are two different metals
and a(n) connecting wire. ____________________
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8. |
Corrosion will eat a hole through aluminum faster than through
iron because aluminum is higher in the activity series. ____________________________________________________________
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9. |
In
cathodic protection, the metal to be protected is made the anode
of the corrosion cell. ____________________
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10. |
Copper would make a suitable sacrificial anode for iron.
____________________
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11. |
In
a battery, the anode and cathode chemicals are mixed together
to produce electricity. ____________________
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12. |
Electrons
leave the cathode of a battery and return through the anode.
____________________
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13. |
In
an electrolytic cell, an external power supply pumps electrons
into the cathode. ____________________
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14. |
The
object to be electroplated is made in the cathode of the electroplating
cell. ____________________
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15. |
The
oxidation of the carbon anodes in the production of aluminum
produces carbon dioxide. ____________________
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Multiple Choice
Identify
the letter of the choice that best completes the statement or answers
the question.
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16. |
The
cell reaction for the zinc–silver cell in Figure 1 is
2
Ag+(aq) + Zn(s) ® 2 Ag(s) + Zn
Figure 1
A zinc–silver cell
Which of these statements about the cell is correct?
a. |
Electrons
flow from silver to zinc. |
b. |
Reduction occurs at the zinc electrode. |
c. |
Anions flow toward the silver half-cell. |
d. |
The mass of the zinc electrode decreases. |
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17. |
What
occurs during the following reaction? 2 Br
+ Cl
®
2 Cl
+ Br
a. |
Br
is oxidized, and its oxidation number increases. |
b. |
Br
is oxidized, and its oxidation number decreases. |
c. |
Br
is reduced, and its oxidation number increases. |
d. |
Br
is reduced, and its oxidation number decreases. |
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18. |
Which
statement best describes the role of the salt bridge in a galvanic cell?
a. |
It
allows electrons to flow from one cell to another. |
b. |
It
allows the two solutions to mix completely. |
c. |
It allows ions to flow. |
d. |
It
allows metal atoms to flow. |
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19. |
Which
of the following factors affect the rate of corrosion?
a. |
moisture |
c. |
different
metals in contact |
b. |
dissolved ions |
d. |
all of the above |
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20. |
What
occurs in the corrosion of iron?
a. |
Reduction of oxygen occurs at the cathode,
and oxidation of iron occurs at the anode. |
b. |
Reduction of iron occurs at the cathode,
and oxidation of water occurs at the anode. |
c. |
Reduction of Fe
occurs at the cathode, and oxidation of water occurs at the anode. |
d. |
Reduction of oxygen occurs at the anode,
and oxidation of iron occurs at the cathode. |
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21. |
Which
statement best describes Ni–Cd batteries?
a. |
They can be disposed of in the regular garbage. |
b. |
They are used in watches and heart pacemakers. |
c. |
They can be recharged completely hundreds
of times. |
d. |
They cannot be fully recharged because of
the “memory effect.” |
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22. |
How
does a fuel cell differ from a battery?
a. |
It must be attached to an external power
source. |
b. |
Its chemicals are continually supplied. |
c. |
It can be recharged using a power supply. |
d. |
It has neither an anode nor a cathode. |
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23. |
Which
of the following statements about electrolysis is NOT true?
a. |
An
external power source is required. |
b. |
Reduction occurs at the cathode. |
c. |
Electrons
flow from the cathode to the anode. |
d. |
An electrolyte is required. |
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24. |
Which
half-reaction occurs at the cathode of a copper electroplating cell?
a. |
Cu(s)
+ 2 e– ® Cu |
c. |
Cu
®
Cu(s) + 2 e– |
b. |
Cu(s) ® Cu
+ 2 e– |
d. |
Cu +
2 e– ® Cu(s) |
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25. |
Which
of the following is NOT an electrolytic process?
a. |
corrosion |
c. |
the production of aluminum |
b. |
chrome
plating |
d. |
recharging
a battery |
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