Chemistry (Chang), 10th Edition

Chapter 19: Electrochemistry

Self Assessment A

1
When the following redox reaction is balanced, the coefficient for S is _____. HNO3 + H2S ----> NO + S + H2O
A)1
B)3
C)4
D)8
E)10
2
Which is true about the following balanced redox reaction:

3 CuO(s) + 2 NH3(aq) ----> N2(g) + 3 H2O(l) + 3 Cu(s)?
A)CuO is the oxidizing agent and Cu is oxidized.
B)CuO is the reducing agent and Cu is reduced.
C)CuO is the oxidizing agent and Cu is reduced.
D)CuO is the reducing agent and Cu is oxidized.
3
Which component of the following cell is the cathode? K|L||M|N
A)K
B)L
C)M
D)N
4
A voltaic cell is prepared using zinc and iron. Its cell notation is as follows: Zn|Zn2+(1 M)||Fe2+(1 M), Fe3+(1M)|Pt. Which of the following reactions occurs at the cathode?
A)Fe3+ + e- ----> Fe2+
B)Fe2+ ----> Fe3+ + e-
C)Zn ----> Zn2+ + 2 e-
D)Zn2+ + 2e- ----> Zn
5
A cell can be prepared from zinc and iron. What is the Eocell for the cell that forms from the following half reactions? Fe3+ + e- ----> Fe2+, Eo = 0.77 V; Zn2+ + 2e- ----> Zn, Eo = -0.76 V
A)-1.53 V
B)-0.01 V
C)0.78 V
D)0.01 V
E)1.53 V
6
Examine the following half-reactions and select the strongest oxidizing agent among the substances:

Sr2+ + 2 e- ----> Sr, Eo = -2.89 V;

Cr2+ + 2 e- ----> Cr, Eo = -0.913 V;

Fe2+ + 2 e- ----> Fe, Eo = -0.447 V;

Co2+ + 2 e- ----> Co, Eo = -0.28 V.
A)Cr2+
B)Sr2+
C)Co2+
D)Fe2+
7
Calculate the equilibrium constant for the reaction:

2 Cr + 3 Pb2+ ----> 3 Pb + 2 Cr3+ at 25oC. Eocell = 0.61 V.
A)4 x 1020
B)8 x 1030
C)9 x 1045
D)3 x 1051
E)8 x 1061
8
The equilibrium constant for the reaction of Ni2+ with Cd is 1.17 x 105. Calculate the free energy change for the reaction at 25oC.
A)-12.6 kJ
B)-28.9 kJ
C)2.43 kJ
D)28.9 kJ
E)12.6 kJ
9
What is the potential of the following cell:

Cu|Cu2+(0.001 M)||Cu2+(1 M)|Cu?

[Cu2+ + 2e- ----> Cu, Eo = 0.342 V]
A)-0.253 V
B)0.253 V
C)-0.0887 V
D)0.0887 V
E)None of the above
10
What mass of copper can be deposited by the passage of 12.0 A for 25.0 min through a solution of copper(II) sulfate? [1 C = 1 A·s; F = 96,500 C]
A)5.93 g
B)3.95 g
C)1.97 g
D)11.85 g
E)29.6 g
11
When balancing equations with the ion-electron method:
A)H2O, H+, and OH- ions are added when using a basic solution.
B)H2O, OH- ions are added when using an acidic solution.
C)Only H2O is added when using a basic solution.
D)None of the above
12
Separating redox equations is simpler if the equation is separated into oxidation and reduction portions.
A)True
B)False
13
Which of the following does not denote the difference in electrical potential between the anode and cathode?
A)cell voltage
B)electromotive force
C)voltmeter
D)cell potential
14
The same electrode may act as either the anode or the cathode depending on the second electrode used in setting up the galvanic cell.
A)True
B)False
15
According to the diagonal rule:
A)Any species on the left of a particular half-cell reaction reacts spontaneously with a species on the right of any half-cell reaction below the first.
B)Any species on the left of a particular half-cell reaction reacts spontaneously with a species on the left of any half-cell reaction below the first.
C)Any species on the left of a particular half-cell reaction will not react spontaneously with a species on the right of any half-cell reaction below the first.
D)None of the above.
Glencoe Online Learning CenterScience HomeProduct InfoSite MapContact Us

The McGraw-Hill CompaniesGlencoe

Please read our Terms of Use and Privacy Notice before you explore our Web site. To report a technical problem with this Web site, please contact the Web Producer.