Section 16.1
The Nature of Oxidation-Reduction Reactions
Practice Test
1.
A reaction in which _____________ are lost and gained is an oxidation-reduction reaction.
a.
electrons
b.
hydrogen ions
c.
neutrons
d.
protons
Hint
2.
What is the oxidation number of iron in Fe
2
O
3
?
a.
3+
b.
1+
c.
2+
d.
2-
Hint
3.
What is the oxidation number of oxygen as a free element?
a.
0
b.
1-
c.
2-
d.
2+
Hint
4.
What is the oxidation number of chlorine in KClO
3
?
a.
5+
b.
3+
c.
1-
d.
1+
Hint
5.
When sodium reacts with sulfur to form sodium sulfide, each sulfur atom ________________.
a.
gains one electron
b.
gains two electrons
c.
loses one electron
d.
loses six electrons
Hint
6.
Sodium __________ when it reacts with sulfur to form sodium sulfide.
a.
gains one electron
b.
gains two electrons
c.
is oxidized
d.
is reduced
Hint
7.
What is the oxidizing agent in the reaction Cu(s) + 2AgNO
3
(aq)
2Ag(s) + Cu(NO
3
)
2
(aq)?
a.
Ag
1+
b.
NO
3
1-
c.
Cu
d.
Ag(s)
Hint
8.
What is the reducing agent in the reaction Cu(s) + 2AgNO
3
(aq)
2Ag(s) + Cu(NO
3
)
2
(aq)?
a.
Ag(s)
b.
Ag
1+
c.
Cu
d.
NO
3
1-
Hint
9.
Which element is oxidized in the reaction BaCl
2
(aq) + Na
2
SO
4
(aq)
2NaCl(aq) + BaSO
4
(s)?
a.
Ba
b.
Cl
c.
Na
d.
none
Hint
10.
What chemical species is oxidized in the reaction represented by the unbalanced equation H
2
O
2
(l) + Br
-
(aq)
Br
2
(aq) + H
2
O(l)?
a.
Br
-
b.
H
2
O
2
c.
O
-
d.
H
2
O
2
Hint
11.
What chemical species is reduced in the reaction described in question 23?
a.
Br
-
b.
Br
2
c.
H
2
O
2
d.
O
-
Hint
12.
Which of the following describes oxidation?
a.
gain of electrons
b.
gain of positive charge
c.
loss of electrons
d.
loss of positive charge
Hint
13.
Determine the net change in oxidation number of chlorine in the following reaction: ClO4- (aq) + Br- (aq) ® Cl- (aq) + Br2(g) (in acid solution)
a.
-8
b.
-7
c.
7
d.
8
Hint
