Name ______Date ______
Electrochemistry Review Test
AP Chemistry
MULTIPLE CHOICE
Each of the following sentences can be completed correctly with one of the items listed below it. Choose the item and write the letter that precedes your choice in the appropriate space to the left of the question. 3 points each.
1).What is the oxidation state of Cr in Cr2O72–?
A)+7
B)+6
C)+12
D)–1
E)–2
2.Which of the following reactions does not involve oxidation-reduction?
A)CH4 + 3O2 2H2O + CO2
B)Zn + 2HCl ZnCl2 + H2
C)2Na + 2H2O 2NaOH + H2
D)MnO2 + 4HCl Cl2 + 2H2O + MnCl2
E)All are oxidation-reduction reactions.
3.In the following reaction, which species is oxidized?
8NaI + 5H2SO4 4I2 + H2S + 4Na2SO4 + 4H2O
A)sodium
B)iodine
C)sulfur
D)hydrogen
E)oxygen
4.The following reaction occurs in basic solution:
F2 + H2O O2 + F–
When the equation is balanced, the sum of the coefficients is:
A)10
B)11
C)12
D)13
E)none of these
5.How many electrons are transferred in the following reaction?
Fe + 2HCl FeCl2 + H2
A)0
B)1
C)2
D)4
E)not enough information given
6.Which of the following species cannot function as an oxidizing agent?
A)S(s)
B)NO3–(ag)
C)Cr2O7–2(aq)
D)I– (aq)
E)MnO4–(aq)
7.Which of the following is the best reducing agent?
Cl2 + 2e– 2Cl–E° = 1.36 V
Mg2+ + 2e– MgE° = –2.37 V
2H+ + 2e– H2E° = 0.00 V
A)Cl2
B)H2
C)Mg
D)Mg2+
E)Cl–
8.A cell is set up with copper and lead electrodes in contact with CuSO4(aq) and Pb(NO3)2(aq), respectively, at 25°C. The standard reduction potentials are:
Pb2+ + 2e– PbE° = –0.13 V
Cu2+ + 2e– CuE° = +0.34 V
If the Pb2+ and Cu2+ are each 1.0 M, the potential of the cell, in volts, is:
A)0.46
B)0.92
C)0.22
D)0.58
E)none of these
9) Write the line notation for the cell in number 8.
10. The galvanic cell described by
Zn(s) | Zn2+(aq) || Cu2+(aq) | Cu(s) has a standard cell potential of 1.101 volts. Given that Zn(s) Zn2+(aq) + 2e– has an oxidation potential of 0.762 volts, determine the reduction potential for Cu2+.
A)–1.863 V
B)1.863 V
C)–0.339 V
D)0.339 V
E)none of these
11.Choose the correct statement given the following information:
Fe3+(aq) + e– Fe2+(aq) E° = 0.77 volt
Fe(CN)63– + e– Fe(CN)64- E° = 0.36 volt
A) Fe2+(aq) is more likely to be oxidized than Fe2+ complexed to CN–.
B) Fe3+(aq) is more likely to be reduced than Fe3+ complexed to CN–.
C) Both a and b are true.
D) Complexation of Fe ions with CN– has no effect on their tendencies to become oxidized or reduced.
E) None of these is true.
13.Consider the following reduction potentials:
Cu2+ + 2e– CuE° = +0.34 V
Pb2+ + 2e– PbE° = –0.13 V
For a galvanic cell employing the Cu, Cu2+ and Pb, Pb2+ couples, calculate the maximum amount of work that would accompany the reaction of one mole of lead under standard conditions.
A)–40.5 kJ
B)–45.3 kJ
C)–90.7 kJ
D)No work can be done. The system is at equilibrium.
E)none of these
Us e this for 16-18
ReactionE° (volts)
Na++e– Na–2.71
Al3++3e– Al–1.66
Fe2++2e– Fe-0.44
Cu2++2e– Cu+0.34
Ag++e– Ag+0.80
Cl2+2e– 2Cl–+1.36
F2+2e– 2F–+2.87
16.Which of the following would be the best oxidizing agent?
A)Cl2
B)Fe
C)Na
D)Na+
E)F–
17.Copper will spontaneously reduce which of the following?
A)Fe2+ and Ag+
B)Fe2+
C)Ag+
D)Al3+
E)Fe2+ and Al3+
18.Determine the standard potential, E°, of a cell that employs the reaction
Fe + Cu2+ Fe2+ + Cu.
A)–0.10 V
B)0.20 V
C)0.10 V
D)0.78 V
E)–0.78 V
19-20
Consider a galvanic cell based in the reaction
Fe2+ + Cr2O72– Fe3+ + Cr3+ in acidic solution.
19.What is the coefficient of Fe3+ in the balanced equation?
A)1
B)2
C)3
D)4
E)none of these
20.Calculate the voltage of the standard cell carrying out this reaction. Use the table in your book. On the test you will have the values you need.
A)0
B)0.21 V
C)–0.21 V
D)0.56 V
E)–0.56 V
23An antique automobile bumper is to be chrome plated. The bumper, which is dipped into a solution of Cr3+ solution, serves as a cathode of an electrolytic cell.
If the current is 10.0 amperes, how long will it take to deposit 1.00 x 102 grams of Cr(s) onto the bumper?
A)15.5 h
B)1.29 days
C)309 min
D)76.3 s
E)2 mo, 25 days, 14 h, and 6 s
24. What quantity of charge is required to reduce 40.0 g of CrCl3 to chromium metal?
A)2.45 x 104 C
B)7.31 x 104 C
C)2.20 x 105 C
D)9.65 x 104 C
E)none of these
Answers
1) b 2) e 3)b 4)d 5)c 6)d 7)c 8) a 9) 10)d 11)b
16)a 17)c 18)d 19)e 20)d 23)a 24)b