Section 21.3
Electrolysis
Practice Test
1.
Why is electrolysis needed to produce pure metals?
SC.A.2.4.5
a.
Metals would rather be cations.
b.
Metals would rather be anions.
c.
Metals are always neutral.
d.
Metals are easily reduced.
Hint
2.
The Hall-Héroult process, which is used to make aluminum metal, electrolyzes a molten mixture of aluminum oxide and cryolite
Na
3
AlF
6
to reduce aluminum cations to aluminum metal. Why is the cryolite used in this mixture?
SC.A.2.4.3
a.
The cryolite raises the cell potential for the reduction of aluminum cations.
b.
The cryolite increases the conductivity of the mixture.
c.
The cryolite lowers the cell potential for the reduction of aluminum cations.
d.
The cryolite lowers the melting point of the mixture and thereby lowers the cost of manufacture by lowering the amount of heat energy needed to melt the mixture.
Hint
3.
In an electrolytic cell, the electrode that acts as a source of electrons to the solution is called the __________; the chemical change that occurs at this electrode is called ________.
a.
anode, oxidation
b.
anode, reduction
c.
cathode, reduction
d.
cathode, oxidation
Hint
4.
The use of electric energy to bring about a chemical reaction is ____________.
a.
electrolysis
b.
a galvanic cell
c.
corrosion
d.
spontaneous combustion
Hint
5.
Electroplating is an example of __________.
a.
a fuel cell
b.
a primary battery
c.
a galvanic cell
d.
electrolysis
Hint
6.
Which of the following is not obtained from the electrolysis of an aqueous solution of sodium chloride?
SC.B.1.4.2
a.
H
2
b.
NaOH
c.
Cl
2
d.
Na
Hint
7.
The electrolysis of an aqueous sodium chloride solution using inert electrodes produces gaseous chlorine at one electrode. At the other electrode, gaseous hydrogen is produced, and the solution around the electrode becomes basic. Which of the following equations is the correct equation for the cathode half-reaction in this electrolytic cell?
a.
H
2
+ 2OH
-
→ 2H
2
O + 2e
-
b.
2H
2
O + 2e
-
→ H
2
+ 2OH
-
c.
2Cl
-
→ Cl
2
+ 2e
-
d.
Cl
2
+ 2e
-
→ 2Cl
-
Hint
8.
Consider the electrolysis of an aqueous solution of aluminum fluoride. Which one of the following statements describes what will be observed?
a.
Al metal is produced at one electrode, and O
2
and H
+
are produced at the other.
b.
Al metal is produced at one electrode, and O
2
and H
+
are produced at the other.
c.
Al metal is produced at one electrode, and F
2
is produced at the other.
d.
O
2
and H
+
are produced at one electrode, and H
2
and OH
-
are produced at the other.
Hint
9.
During the electrolysis of molten sodium iodide, sodium ions move ________.
SC.A.1.4.1
a.
to the anode, which is positively charged
b.
to the cathode, which is positively charged
c.
to the cathode, which is negatively charged
d.
to the anode, which is negatively charged
Hint
