Electrochemistry
Practice Test
1.
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.
cathode, reduction
b.
anode, reduction
c.
cathode, oxidation
d.
anode, oxidation
2.
The use of electric energy to bring about a chemical reaction is ____________.
a.
a galvanic cell
b.
electrolysis
c.
corrosion
d.
spontaneous combustion
3.
A chemical reaction generates electric energy spontaneously in ___________.
SC.C.2.4.2
a.
corrosion
b.
electrolysis
c.
a galvanic cell
d.
spontaneous combustion
4.
A cell is constructed by immersing a strip of lead in a 1.0
M
Pb
NO
3
2
solution and a strip of silver in a 1.0
M
AgNO
3
solution. The circuit is completed by a wire and a salt bridge. As the cell operates, the strip of silver gains mass
only silver
, the strip of lead loses mass, and the concentration of lead ions increases in the solution around the lead strip. Which of the following represents the reaction that occurs at the cathode in this cell?
a.
Ag
+
+ e
-
→ Ag
b.
Pb → Pb
2+
+ 2e
-
c.
Pb
2+
+ 2e
-
→ Pb
d.
Ag → Ag
+
+ e
-
5.
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 increases the conductivity of the mixture.
b.
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.
c.
The cryolite raises the cell potential for the reduction of aluminum cations.
d.
The cryolite lowers the cell potential for the reduction of aluminum cations.
6.
The pieces of metal that are placed on the outside of ships to help prevent corrosion are _________.
a.
sacrificial cathodes
b.
electrolyzed metals
c.
sacrificial anodes
d.
galvanized metals
7.
A voltaic cell in which the reaction involves the combustion of one reactant with oxygen to produce electric energy is a
n
_____________.
a.
primary battery
b.
electrolytic cell
c.
secondary battery
d.
fuel cell
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.
O
2
and H
+
are produced at one electrode, and H
2
and OH
-
are produced at the other.
c.
Al metal is produced at one electrode, and F
2
is produced at the other.
d.
Al metal is produced at one electrode, and O
2
and H
+
are produced at the other.
9.
What is the anode reaction when a NiCad battery is used to generate electric current?
SC.C.2.4.5
a.
oxidation of cadmium in the presence of an acid
b.
reduction of cadmium in the presence of a base
c.
oxidation or cadmium in the presence of a base
d.
reduction of cadmium in the presence of an acid
10.
A redox reaction that is not easily reversed is the source of electric energy in a
n
_______.
a.
primary battery
b.
fuel cell
c.
electrolytic cell
d.
secondary battery
11.
Electroplating is an example of __________.
a.
a fuel cell
b.
electrolysis
c.
a primary battery
d.
a galvanic cell
12.
Which of the following is the weakest reducing agent?
a.
F
-
b.
Al
3+
c.
F
2
d.
Al
13.
How many moles of electrons have been transferred between the species in the following reaction? 2Cr
3+
aq
+3Cu
s
→2Cr
s
+3Cu
2+
aq
SC.B.1.4.2
a.
4
b.
3
c.
6
d.
2
14.
A voltaic cell consists of a standard hydrogen electrode connected by a salt bridge and a wire to an electrode consisting of a strip of Cd metal dipping into a 1
M
solution of Cd
NO
3
2
. When the cell produces a current, the electrons flow through the wire from the _________ electrode to the ________ electrode. In this cell, the _______ electrode acts as the cathode.
SC.C.2.4.2
a.
Cd, H
2
, H
2
b.
H
2
, Cd, H
2
c.
Cd, H
2
, Cd
d.
H
2
, Cd, Cd
15.
How does paint protect steel surfaces from corrosion?
SC.C.2.4.2
a.
Paint corrodes leaving steel intact.
b.
Paint prevents the oxidation-reduction reaction of corrosion from occurring.
c.
Paint acts as a sacrificial anode.
d.
Paint galvanizes steel.
