Chapter 17 Review AP
Multiple Choice
1. In a voltaic cell operating under standard conditions, the reaction at the cathode always has a
more positive E°RED than the reaction at the anode. Which of the following best explains why
this is true?
a. The reaction at the anode is an oxidation described by a value given by E°OX not a
reduction described by E°RED.
b. The more positive E°RED value of a redox reaction, the more spontaneous the reaction.
c. Because the anode is negative in a voltaic cell, the value of E°RED at the anode must also
be negative in order for an oxidation to occur.
d. The more positive the value of E°RED at the cathode, the greater the driving force for
reduction.
Questions 2-6 refer to the following:
Half cell 1: Strip of Al (s) in 1.00mol/L Al(NO3)3
Half-cell 2: Strip of Cu(s) in 1.00mol/L Cu(NO3)2
Half-cell 3: Strip of Fe(s) in 1.00mol/L Fe(NO3)2
Half-cell 4: Strip of Zn(s) in 1.00mol/L Zn(NO3)2
Galvanic
Cell
U
V
W
X
Y
Z
Half Cells
Cell Reaction
E°cell (V)
1 and 2
1 and 3
1 and 4
2 and 3
2 and 4
3 and 4
2Al(s)+3Cu2+(aq)2Al3+(aq) + 3 Cu(s)
2Al(s)+3Fe2+(aq)2Al3+(aq) + 3 Fe(s)
2Al(s)+3Zn2+(aq)2Al3+(aq) + 3 Zn(s)
Fe(s)+Cu2+(aq)Fe2+(aq)+Cu(s)
Zn(s)+Cu2+(aq)Zn2+(aq)+Cu(s)
Zn(s)+Fe2+(aq)Zn2+(aq)+Fe(s)
2.00
?
0.90
0.78
1.10
?
2. What is the standard cell potential of galvanic cell V?
a. 0.90V
b. 1.22V
c. 1.88V
d. 2.78V
3. What is the standard cell potential of galvanic cell Z?
a. -1.88V
b. -0.32V
c. 0.32V
d. 1.88V
4. In galvanic cell V and X, which of the following takes place in half-cell 3?
a. In cell V, the oxidation of Fe and in cell X, the reduction of Fe2+
b. In cell V, the reduction of Fe2+ and in cell X, the oxidation of Fe
c. In cell V, The oxidation of Fe2+ and in cell X, the oxidation of Fe
d. In cell V, the reduction of Fe and in cell X, the oxidation of Fe2+
5. In galvanic cell U and Y, which of the following takes place in half-cell 2?
a. In cell U, Cu2+ is reduced, and in cell Y, Cu is oxidized
b. In cell U, Cu is oxidized, and in cell Y, Cu2+ is reduced.
c. In both cells, Cu is oxidized
d. In both cells, Cu is reduced
6. If half-cell 2 containing 1.00M Cu(NO3)2 in galvanic cells U and X is replaced with a half-cell
containing 6.00M Cu(NO3)2, what will be the effect on the cell voltage of the two galvanic cells?
a. The voltage will increase in both cells.
b. The voltage will decrease in both cells.
c. The voltage will increase in cell U, and decrease in cell X.
d. The voltage will increase in cell X, and decrease in cell U.
The following refers to questions 7-8
Zn2+(aq) +2e- Zn(s)
E°=-0.76V
Ag+(aq)+e-Ag(s)
E°=0.80V
7. As the cell operates, which of the following species is contained in the half-cell containing the
anode?
a. Ag+ only
b. Ag and Ag+
c. Zn2+ only
d. Zn2+ and Zn
8. What is the standard cell potential for this galvanic cell?
a. 0.04V
b. 0.84V
c. 1.56V
d. 2.36V
9. An electric current of 1.00 ampere is passed through an aqueous solution of FeCl3. Assuming
100% efficiency, how long will it take to electroplate exactly 1.00 mole of iron metal?
1 faraday=96,500coulombs=6.022x1023 electrons
a. 32,200sec
b. 96,500sec
c. 193,000sec
d. 289,500sec
Free Response
Voltmeter
KNO3
1M
1M
1. Identify the cathode and the anode. Justify your answer.
2. Calculate the voltage on the cell when it is in operation.
3. The mass of each electrode changes as the cell functions. State the change in mass that occurs
at each electrode. If the electrode gained mass, explain where the mass came from. If the
electrode lost mass, explain where the mass went.
4. Draw the ions coming out of the salt bridge in each cell.
5. Suppose the 1M standard solutions were replaced with equal volumes of 0.65M solutions. State
whether the cell potential would be greater then, equal to, or less than what you calculated in
question 2. Explain.
6. Compare the length of time that a device could be powered by the standard cell (1M) versus a
cell in which each half-cell had a concentration of 0.5M. Justify your answer.
7. Write the net ionic equation for the reaction between the Cu and Ag electrodes (in the standard
cell) that would be thermodynamically favorable. Justify the thermodynamic favorability of the
reaction.
8. Calculate ΔG° for the standard cell. (make sure to include units)
9. Imagine a cell in which both the anode and cathode were bathed in a solution of KNO3, as
shown below. State whether you would expect this cell to work. Justify your answer.