Question 1
Of Sn2+, Ag+, and/or Zn2+, which could be reduced by Cu?
◦
Sn2+
◦
Ag+
◦
Zn2+
◦
Two of them could be reduced by Cu.◦
All of them could be reduced by Cu.Question 2
Refer to the galvanic cell below (the contents of each half-cell are written beneath each compartment):
![](data:image/png;base64, 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)
0.10
M MnO
4– 0.40
M Cr
3+0.20
M Mn
2+ 0.30
M Cr
2O
72–0.010
M H
+ 0.010
M H
+The standard reduction potentials are as follows:
MnO
4– + 8H
+ + 5e
–→ Mn
2+ + 4H
2O,
E° = 1.51 V
Cr
2O
72– + 14H
+ + 6e
–→ 2Cr
3+ + 7H
2O,
E° = 1.33 V
When current is allowed to flow, which species is oxidized?
Reference: 18-3
◦
Cr2O72–◦
Cr3+◦
MnO4–◦
Mn2+◦
H+