Chapter 20:
Redox Reactions
Practice Test
1.
What is the oxidation number of O in Na
2
SO
4
?
a.
6
b.
-2
c.
1
d.
2
Hint
2.
What is the oxidizing agent in the following reaction?
6KOH(aq) + 3Cl
2
(g) → KClO
3
(aq) + 5KCl(aq) + 3H
2
O(l)
a.
KCl
b.
KOH
c.
KClO
3
d.
Cl
2
Hint
3.
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.
3
b.
6
c.
2
d.
1
Hint
4.
Oxidation is __________.
a.
the gain of electrons and an increase in charge
b.
the loss of electrons and an increase in charge
c.
the gain of electrons and a decrease in charge
d.
the loss of electrons and a decrease in charge
Hint
5.
Predict the products of the following single-replacement reaction.
Fe(s) + CuSO
4
(aq) → ?
a.
CuS(s) + Fe
2
SO
4
(aq)
b.
FeCuSO
4
c.
Cu(s) + FeSO
4
(aq)
d.
Fe(s) + Cu(s) + SO
4
(aq)
Hint
6.
Select the compound in which chlorine has the highest possible oxidation number.
a.
HClO
b.
HClO
2
c.
HClO
3
d.
HCl
Hint
7.
Complete and balance the following redox equation. When properly balanced with whole—number coefficients, the coefficient of S is _________.
H
2
S + HNO
3
→ S + NO + H
2
O
a.
1
b.
2
c.
3
d.
4
Hint
8.
Group 1A metal ions have an oxidation number of _______.
a.
1
b.
-1
c.
2
d.
3
Hint
9.
Which of the following reactions is a redox reaction?
a.
H
+
(aq) + OH
-
(aq)
H
2
O(l)
b.
CaBr
2
(aq) + H
2
SO
4
(aq)
CaSO
4
(s) + 2HBr(aq)
c.
2Al(s) + 3H
2
SO
4
(aq)
Al
2
(SO
4
)
3
(aq) + 3H
2
(g)
d.
2KBr(aq) + Pb(NO
3
)
2
(aq)
2KNO
3
(aq) + PbBr
2
(s)
Hint
10.
Which species is the reducing agent in the following set of half-reactions?
Cu
2+
+ 2e
-
→ Cu Pb → Pb
2+
+ 2e
-
a.
Cu
2+
b.
Cu
c.
Pb
2+
d.
Pb
Hint
11.
Complete and balance the following chemical reaction with the smallest set of coefficients. What is the coefficient for iodine in this reaction?
HI + HNO
3
→ I
2
+ NO + H
2
O
a.
1
b.
4
c.
3
d.
2
Hint
12.
In a redox reaction, the number of electrons lost by the reducing agent ____________.
a.
equals the number of protons in the reducing agent
b.
equals the number of protons in the oxidizing agent
c.
equals the number of electrons lost by the oxidizing agent
d.
equals the number of electrons gained by the oxidizing agent
Hint
13.
Which of the following types of reactions do not usually involve redox?
a.
single-replacement
b.
decomposition
c.
double-replacement
d.
synthesis
Hint
14.
What is the oxidation number of N in KNO
3
?
a.
5
b.
-3
c.
3
d.
6
Hint
15.
When the following equation is balanced what is the coefficient of Sn?
Sn + HNO
3
→ SnO
2
+ NO
2
+ H
2
O
a.
2
b.
3
c.
1
d.
4
Hint
16.
A balanced reaction that shows only the oxidation process is a ___________.
a.
half-reaction
b.
balanced chemical equation
c.
synthesis reaction
d.
single-replacement reaction
Hint
17.
Which of the following half-reactions represents oxidation?
a.
O
2
+ 4e
-
→ 2O
2-
b.
Fe
3+
+ 3e
-
→ Fe
c.
Fe → Fe
2+
+ 2e
-
d.
Cu
2+
+ 2e
-
-
→ Cu
Hint
18.
The most electronegative atom in a compound has a charge that is __________.
a.
zero
b.
neutral
c.
negative
d.
positive
Hint
19.
The highest possible oxidation number for carbon is ________.
a.
2
b.
6
c.
8
d.
4
Hint
20.
Balance the following equation. How many electrons must be transferred between the reducing agent and the oxidizing agent in this reaction? H
2
S + HNO
3
→ S + NO + H
2
O
a.
4
b.
2
c.
3
d.
6
Hint
