Redox Reactions
Practice Test
1.
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.
3
b.
4
c.
1
d.
2
2.
Which of the following reactions is a redox reaction?
a.
2KBr(aq) + Pb(NO
3
)
2
(aq) → 2KNO
3
(aq) + PbBr
2
(s)
b.
2Al(s) + 3H
2
SO
4
(aq) → Al
2
(SO
4
)
3
(aq) + 3H
2
(g)
c.
H
+
(aq) + OH
-
(aq) → H
2
O(l)
d.
CaBr
2
(aq) + H
2
SO
4
(aq) → CaSO
4
(s) + 2HBr(aq)
3.
The most electronegative atom in a compound has a charge that is __________.
a.
positive
b.
zero
c.
negative
d.
neutral
4.
A balanced reaction that shows only the oxidation process is a ___________.
a.
balanced chemical equation
b.
single-replacement reaction
c.
synthesis reaction
d.
half-reaction
5.
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.
3
b.
2
c.
1
d.
4
6.
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.
8
b.
-7
c.
-8
d.
7
7.
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.
2NO
3
b.
3NO
2
c.
2NO
2
d.
3NO
3
8.
When the following equation is balanced what is the coefficient of Sn?
Sn + HNO
3
→ SnO
2
+ NO
2
+ H
2
O
a.
4
b.
1
c.
2
d.
3
9.
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
0
a.
4
b.
2
c.
6
d.
3
10.
Oxidation is __________.
a.
the loss of electrons and a decrease in charge
b.
the gain of electrons and a decrease in charge
c.
the loss of electrons and an increase in charge
d.
the gain of electrons and an increase in charge
11.
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
12.
What is the oxidizing agent in the following reaction?
6KOH(aq) + 3Cl
2
(g) → KClO
3
(aq) + 5KCl(aq) + 3H
2
O(l)
a.
Cl
2
b.
KOH
c.
KCl
d.
KClO
3
13.
Balance the following ionic equation. What is the coefficient of the reducing agent in this reaction?
Fe
2+
(aq) + MnO
4
-
(aq) + H
+
(aq) → Fe
3+
(aq) + Mn
2+
(aq) + H
2
O(l)
a.
1
b.
4
c.
5
d.
8
14.
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.
1
c.
2
d.
6
15.
Which of the following half-reactions represents oxidation?
a.
Cu
2+
+ 2e
-
→ Cu
b.
Fe → Fe
2+
+ 2e
-
c.
Fe
3+
+ 3e
-
→ Fe
d.
O
2
+ 4e
-
→ 2O
2-
