Reduction Potentials at 25°C
F2(g) + 2 e
–
H2O2(aq) + 2 H (aq) + 2 e
–
–
+
MnO4 (aq) + 8 H (aq) + 5 e
Cl2(g) + 2 e–
2–
+
Cr2O7 (aq) +14 H (aq) + 6 e
+
O2(g) + 4 H (aq) + 4 e
+
–
–
Ag (aq) + e
O2(g) + 2 H (aq) + 2 e
Cu (aq) + 2 e
H2(g)
0.00
Mn (aq) + 4 H2O(l) 1.51
2+
Pb (aq) + 2 e
–
Pb(s)
–0.13
2 Cl–(aq)
Ni2+(aq) + 2 e–
Ni(s)
–
–0.26
1.36
3+
2 Cr (aq) + 7 H2O(l) 1.33
2 H2O(l)
1.23
1.09
Sn (aq) + 2 e
2 H (aq) + 2 e
Cd(s)
–0.40
2+
–
Fe(s)
–0.45
2+
–
Zn(s)
Cd (aq) + 2 e
Fe (aq) + 2 e
Zn (aq) + 2 e
–
0.80
2 H2O(l) + 2 e
0.77
Al3+(aq) + 3 e–
–
0.70
0.54
4 OH (aq)
0.40
Cu(s)
0.34
2+
Mg (aq) + 2 e
+
Na (aq) + e
+
Li (aq) + e
5.
CrO3
I2
Cu2+
MnO4–
Ni
Fe2+ and Ag+
Fe2+
Ag+
Al3+
Fe2+ and Al3+
3.
Which of the following is the best oxidizing agent under
standard conditions at 25°C?
a) Ag(s)
b) I–(aq)
c) Pb2+(aq)
d) Zn(s)
e) Al3+(aq)
4.
Which of the following is the best reducing agent under
standard conditions at 25°C?
a) Ag(s)
b) I–(aq)
c) Pb2+(aq)
d) Zn(s)
e) Al3+(aq)
–0.76
–
H2(g) + 2 OH (aq) -0.83
–
–
–
Al(s)
–1.66
Mg(s)
–2.37
Na(s)
–2.71
Li(s)
–3.04
Consider a voltaic cell constructed by connecting a
standard Zn/Zn2+ half cell to a standard Cu/Cu2+ half
cell. Which of the following statements is false?
The concentration of Cu2+(aq) decreases during
discharge.
b) The mass of the zinc electrode increases during
discharge.
c) Electrons flow through the external circuit from the
zinc electrode to the copper electrode.
d) Reduction occurs at the copper electrode during
discharge.
e) The copper electrode is the cathode.
a)
Solid copper will spontaneously reduce which of the
following?
a)
b)
c)
d)
e)
–
Fe2+(aq)
H2O2(aq)
2+
2+
Ag(s)
2 I (aq)
–
1.78
2+
–
–
2.87
Which of the species below cannot function as an
oxidizing agent?
a)
b)
c)
d)
e)
2.
–
–
O2(g) + 2 H2O(l) + 4 e
1.
0.15
–
2 Br (aq)
–
+
2+
Sn (aq)
+
–
Fe3+(aq) + e–
I2(s) + 2 e
–
2 H2O(l)
–
E°(V)
4+
2 F (aq)
+
Br2(l) + 2 e
E° (V)
–
6.
A galvanic cell is constructed using a Ni(s) | Ni2+(aq)
half-cell and a Ag(s) | Ag+(aq) half-cell. The two
solutions are connected with a salt bridge, and the Ni(s)
electrode is connected to the Ag(s) electrode with a wire.
Which statement below is correct?
a) The electrons move through the wire toward the
nickel electrode, which is the anode.
b) The electrons move through the wire towards the
nickel electrode, which is the cathode.
c) The electrons move through the wire towards the
silver electrode, which is the anode.
d) The electrons move through the wire towards the
silver electrode, which is the cathode.
e) Electrons will not move through the wire, because
this is not a spontaneous reaction.
7.
What is the cell potential for the following galvanic cell
at standard conditions and 25°C?
Ni(s) | Ni2+(1.0 M) || Ag+(1.0 M) | Ag(s)
a)
b)
c)
d)
e)
0.54 V
1.34 V
1.86 V
1.06 V
0.93 V
8.
A voltaic cell is prepared by connecting a Zn/Zn2+ half
cell with a Ag/Ag+ half cell. What is the cell potential at
25°C if [Zn2+] = 0.100 M and [Ag+] = 10.0 M?
a)
b)
c)
d)
e)
9.
0.04 V
1.47 V
1.38 V
1.65 V
1.56 V
The following galvanic cell has a standard potential at
25°C of 1.94 V. What is the standard reduction
potential for Ce3+(aq) at 25°C?
Ce(s) | Ce3+ (1M) || Cd2+ (1M) | Cd(s)
a)
b)
c)
d)
e)
10.
2.34 V
-2.34 V
1.57 V
-1.57 V
1.54 V
What is the pH of the solution in the anode half cell of
the following galvanic cell if the measured cell
potential at 25°C is 0.28 V?
Pt(s) | H2 (1 atm) | H+ (?? M) || Pb2+ (1 M) | Pb(s)
a)
b)
c)
d)
e)
2.5
0.14
6.9
14
11.5
11. A concentration cell can be prepared using a half cell
consisting of a Cu(s) electrode in a 0.30 M solution of
Cu2+(aq) and a half cell consisting of a Cu(s) electrode in
a 0.10 M solution of Cu2+(aq). What is the cell potential
at 25°C and which electrode is the cathode?
a)
0.014 V, Cu(s) electrode in the 0.30 M solution of
Cu2+(aq)
b) 0.028 V, Cu(s) electrode in the 0.30 M solution of
Cu2+(aq)
c) –0.014 V, Cu(s) electrode in the 0.10 M solution of
Cu2+(aq)
d) –0.028 V, Cu(s) electrode in the 0.10 M solution of
Cu2+(aq)
e) 0.014 V, Cu(s) electrode in the 0.10 M solution of
Cu2+(aq)