Chapter 18
Oxidation-Reduction Reactions and Electrochemistry
I.
Matching
Match the description in Column B with the correct term in Column A. Write the letter in the
blank provided. Each term matches with only one description, so be sure to choose the best
description for each term.
Column A
Column B
_____
1. oxidation-reduction reaction
A. electrode where reduction occurs
_____
2. oxidation
B. reactant containing an element that is reduced
_____
3. reduction
C. battery
_____
4. oxidizing agent
D. naturally occuring oxidation of metals
_____
5. reducing agent
E. reaction in which electrons are transferred
_____
6. electrochemistry
F. loss of electrons
_____
7. galvanic cell
G. process where electrical energy is used to
produce a chemical change
_____
8. anode
_____
9. cathode
H. electrode where oxidation occurs
_____ 10. electrolysis
I. study of the inerchange of chemical and
electrical energy
_____ 11. corrosion
J. gain of electrons
K. reactant containing an element that is oxidized
II.
Multiple Choice
Choose the one best answer and write its letter in the blank.
_____ 12.
The oxidation half-reaction among the following is:
a) Cu(s)  Cu2+(aq) + 2 e–
b) 2 F–(aq)  F2(g) + 2 e–
_____ 13.
c) Ag+(aq) + e–  Ag(s)
d) V2+(aq)  V3+(aq) + e–
In which of the following does nitrogen have an oxidation state of +4?
a) NH3
b) NH4Cl
c) NO2
d) HNO3
_____ 14.
For the oxidation-reduction reaction 4 Na (s) + O2 (g)  2 Na2O (s), which
species is oxidized?
c) Na+
d) O2-
a) Na
b) O2
_____ 15.
For the oxidation-reduction reaction 2 K (s) + Cl2 (g)  2 KCl (s), the K is:
a) the oxidizing agent
b) the reducing agent
_____ 16.
Which of the following is NOT an oxidation-reduction reaction?
a)
b)
c)
d)
_____ 17.
c) the electron acceptor
d) reduced
CH4(g) + 2 O2(g)  2 H2O(g) + CO2(g)
AgNO3(aq) + KCl(aq)  AgCl(s) + KNO3(aq)
2 Al(s) + 3 CuCl2(aq)  3 Cu(s) + 2 AlCl3(aq)
N2(g) + 3 H2(g)  2 NH3(g)
Which of the following is true?
Oxidation and reduction
a)
b)
c)
d)
______ 18.
never accompany each other in a reaction.
involve the gain and loss of electrons, respectively.
involve a change in the oxidation states of the elements involved.
occur in all chemical reactions.
Which of the following is true for the reaction below?
Zn(s)
+
2 HNO3(aq)

Zn(NO3)2(aq)
a) Zn is reduced.
b) H is reduced.
MnO4–(aq)
_____ 19.
+
Br–(aq)

H2(g)
c) N is reduced.
d) O is reduced.
MnO2(s)
+
BrO3–(aq)
The oxidation state of manganese in MnO4- is:
a) +1
b) +3
_____ 20.
+
c) +4
d) +7
What is the energy conversion that takes place in a galvanic cell?
a) chemical to electrical
b) electrical to chemical
c) chemical to mechanical
d) mechanical to chemical
_____ 21.
The component in an electrochemical cell that allows for ion migration is the
a) wire.
b) cathode.
_____ 22.
c) anode.
d) salt bridge.
The component in an electrochemical cell where loss of electrons takes place is
the
a) wire.
b) cathode.
23.
24.
c) anode.
d) salt bridge.
Assign the oxidation state for sulfur in each of the following compounds:
a) H2S
_____
d) SO3
_____
b) H2SO4
_____
e) S8
_____
c) SO2
_____
For the reaction below, identify what is being oxidized, what is being reduced, the
oxidizing agent, and the reducing agent.
CH4(g)
+
O2(g)

CO2(g)
+
H2O(g)
oxidized: _____________
oxidizing agent: ______________
reduced: _____________
reducing agent: ______________
25. Draw a voltaic cell for a reaction with iron (II) and silver. Label the anode, cathode,
direction of electron flow, solutions. Also write out the half reactions and complete reaction.
26. Draw an electrolytic cell where tin will be plated by gold. Label the anode, cathode,
direction of electron flow, solutions, ion flow in solution and half-reactions for each cell.
Answer Key Chapter 18
1. E 2. F 3. J
12. C 13. C 14. A
23. a. –2
b. +6
24.
oxidized:
reduced
4. B 5. K 6. I
7. C 8. H
15. B 16. B 17. D 18. B 19. D
c. +4 d. +6 e. 0
C
oxidizing agent
O
reducing agent:
9. A 10. G 11. D
20. A 21. D 22. C
O2
CH4
e-
25.
Cathode
Ag
Anode
Fe
Cathode
Ag+
Fe2+
2(Ag+ + e-  Ag)
2Ag+ + 2e-  2Ag
Fe  Fe2+ + 2e-
2Ag+ + Fe  2Ag + Fe2+
26.
Anode
ee-
Cathode
Ag
Sn
Cathode
Cathode
Ag+
Cathode Ag+ + e-  Ag
Anode Ag + e-  Ag+
+