Electrochemistry
Practice Test
1.
The acid ionization constant,
K
a
, is __________ for __________ acids.
a.
largest, anhydride
b.
smallest, weak
c.
largest, weak
d.
smallest, strong
2.
How does paint protect steel surfaces from corrosion?
a.
Paint galvanizes steel.
b.
Paint acts as a sacrificial anode.
c.
Paint prevents the oxidation-reduction reaction of corrosion from occurring.
d.
Paint corrodes leaving steel intact.
3.
The highest possible oxidation number for carbon is ________.
a.
6
b.
4
c.
+8
d.
2
4.
What is the net change in oxidation number of iodine in the following ionic reaction?
2MnO
4
-
+ I
-
+ H
2
O → 2MnO
2
+ IO
3
-
+ 2OH
-
a.
1
b.
6
c.
2
d.
3
5.
Which of the following reactions is a redox reaction?
a.
2KBr(aq) + Pb(NO
3
)
2
(aq) → 2KNO
3
(aq) + PbBr
2
(s)
b.
H
+
(aq) + OH
-
(aq) → H
2
O(l)
c.
CaBr
2
(aq) + H
2
SO
4
(aq) → CaSO
4
(s) + 2HBr(aq)
d.
2Al(s) + 3H
2
SO
4
(aq) → Al
2
(SO
4
)
3
(aq) + 3H
2
(g)
6.
The value of the
K
sp
for SrSO
4
is 2.8 x 10
-7
. What is the molar solubility of SrSO
4
?
a.
5.8 x 10
-13
M
b.
7.6 x 10
-7
M
c.
5.7 x 10
-3
M
d.
5.3 x 10
-4
M
7.
A 0.001
M
solution of HCl is ____________.
a.
a weak acid solution
b.
a concentrated acid solution
c.
a dilute acid solution
d.
neutral
8.
Which of the following would force the forward reaction to completion?
CaCO
3
(s) + 2H
3
O
+
(aq) → Ca
2+
(aq) + 3H
2
O(l) + CO
2
(g)
a.
conduct the experiment in an open container
b.
add CO
2
to the mixture
c.
add base to neutralize the H
3
O
+
d.
add more Ca
2+
to the mixture
9.
Name the spectator ion in the following equation, including the correct coefficient:
Cu(s) + 4HNO
3
(aq) → Cu(NO
3
)
2
(aq) + 2NO
2
+ 2H
2
O (l)
a.
3NO
3
b.
2NO
3
c.
2NO
2
d.
3NO
2
10.
Determine the net change in oxidation number of chlorine in the following reaction:
ClO
4
-
(aq) + Br
-
(aq) → Cl
-
(aq) + Br
2
(g) (in acid solution)
a.
-7
b.
-8
c.
8
d.
7
11.
Which of the solubility product expressions is incorrect?
a.
K
sp
(Ag
2
S) = [Ag
+
]
2
[S
2-
]
b.
K
sp
(CuS) = [Cu
2+
][S
2-
]
c.
K
sp
(CaF
2
) = [Ca
2+
][F
-
]
2
d.
K
sp
(Sb
2
S
3
) = [Sb
2+
]
3
[S
3-
]
2
12.
In any electrochemical cell, the cathode is the ________.
a.
electrode at which some species gains electrons
b.
negative electrode
c.
electrode at which some species loses electrons
d.
positive electrode
13.
Calculate the H
+
ion and OH
-
ion concentrations in a 0.50
M
solution of HBr.
a.
[H
+
] = 0.50
M
and [OH
-
] = 2.0 ´ 10
-14
M
b.
[H
+
] = 0.50
M
and [OH
-
] = 0.50
M
c.
[H
+
] = 1.0 ´ 10
-7
M
and [OH
-
] = 1.0 ´ 10
-7
M
d.
[H
+
] = 0.50
M
and [OH
-
] = 2.0
M
14.
During the electrolysis of molten sodium iodide, sodium ions move ________.
a.
to the anode, which is negatively charged
b.
to the cathode, which is negatively charged
c.
to the anode, which is positively charged
d.
to the cathode, which is positively charged
15.
Which of the following is not obtained from the electrolysis of an aqueous solution of sodium chloride?
a.
NaOH
b.
Na
c.
H
2
d.
Cl
2
16.
Which of the following salts will produce a basic solution?
a.
KBr
b.
NaCl
c.
KCN
d.
Ca(NO
3
)
2
17.
Which of the following must be true of a salt bridge?
a.
The solutions joined by the salt bridge can mix freely.
b.
The tube of the salt bridge must remain open.
c.
Ions can move through the salt bridge.
d.
The salt bridge must prevent the flow of charged particles.
18.
Balance the following equation with the smallest whole—number coefficients. How many moles of zinc will react with 6 moles of cobalt(III) chloride?
Zn(s) + CoCl
3
(aq) → ZnCl
2
(aq) + Co(s)
a.
2
b.
9
c.
6
d.
3
19.
A chemical reaction generates electric energy spontaneously in ___________.
a.
corrosion
b.
a galvanic cell
c.
electrolysis
d.
spontaneous combustion
20.
For the system, H2(g) + CO2(g) → H2O(g) + CO(g) at equilibrium, the addition of H2(g) would cause ____________.
a.
more H
2
O and CO to form
b.
only more H
2
O to form
c.
only more CO to form
d.
only more CO
2
to form
