Chemistry 12
Name:
Date:
Block:
Electrochemistry I Worksheet
Define each
1. Oxidation
2. Reduction
3. Oxidizing agent
4. Reducing agent
- loss of electrons
- gain of electrons
- causes oxidation by undergoing reduction
- causes reduction by undergoing oxidation
Write half reactions for each of the following atoms or ions. Label each as oxidation or reduction.
5.
Al
----------->
6.
S
+
7.
2O2- ---------->
8.
Ba2+
10.
Br2
11.
P +
12.
Ca
oxidation
S2-
O2 +
reduction
4e-
oxidation
2e- --------->
3e-
---------->
----------->
reduction
N2 +
+
Ga3+
S
3e-
+ 2e- -----------> Ba
2N3- ---------->
14.
+
2e- --------->
9.
13
Al3+
Ca2+
6e-
oxidation
2Br-
reduction
P3+
reduction
2e-
oxidation
+ 3e- -----------> Ga
reduction
2e- --------->
reduction
+
2H+
S2-
15.
H2
--------->
+ 2e-
16.
2H+
+ 2e- ---------> H2
17.
2F-
---------->
F2 +
18.
P3-
---------->
P +
oxidation
reduction
2e-
oxidation
3e-
oxidation
Balance each spontaneous redox equation. Identify the entities reduced and oxidized. State the reducing
agent and the oxidizing agent.
19. Al
&
Zn2+
2Al +
oxidized
reducing agent
20. F2
&
&
3Zn
O2-
2F2 +
reduced
oxidizing agent
21. O2
3Zn2+
→
2Al3+ +
reduced
oxidizing agent
2O2→
4Foxidized
reducing agent
+
O2
Ca
2Ca +
oxidized
reducing agent
O2
→
reduced
oxidizing agent
2Ca2+ +
2O2-
22. Al3+
&
Li
Al3+ +
reduced
oxidizing agent
3Li
→
Al
oxidized
reducing agent
+
3Li+
Label the species that is reduced, that is oxidized, the reducing agent and the oxidizing agent.
23.
Fe2+
+
Co
→
Co2+
Co → Co2+ + 2e- oxidation
24.
3 Ag+
Ni
25.
+
→ Ni2+
+ 2e-
Cu2+
26.
+
Pb
Pb
→ Pb2+
+ 2e-
O2
+
Sn →
27.
Ni
Sn2+
Co2+
2F-
2 Sn
→
+ 2e-
+
2 F-
F2
+ 2e-
Fe2+
→
oxidation
→
Ag+
→
Ni
Pb
Sn
Ag+
Cu2+ O2
1e- → Ag
+
oxidation
Co2+
reduction
2 Sn2+
+ 4e- → 2O2-
+
reduction
Cu
+ 2e- → Cu
O2
F-
Co2+
+
O2-
29. List the species (formulas from above) that gain electrons:
Fe2+
3 Ag
+
Co
→ Fe reduction
+
Cu2+
oxidation
→
2e-
Pb2+
oxidation
Fe
+
Ni3+
28. List the species (formulas from above) that lose electrons:
Co
+
reduction
F2
+ 2e-
→ Co
reduction
For each of the following reactions, identify:
-The Oxidizing Agent.
-The Reducing Agent.
-The Substance Oxidized.
-The Substance Reduced.
30.
I-
+
Cl2
---------->
Cl-
Substance oxidized IOxidizing agent
Cl2
31.
Co
+
Fe3+
Cr6+
+
----------->
Fe2+
I2
Reducing agent
Substance reduced
Substance oxidized Co
Oxidizing agent
Fe3+
32.
+
Co2+
+
Fe2+
Reducing agent
Substance reduced
----------->
Substance oxidized Fe2+
Oxidizing agent
Cr6+
Cr3+
ICl2
+
Co
Fe3+
Fe3+
Reducing agent
Substance reduced
Fe2+
Cr6+
33. State the Oxidation Number of each of the elements that is underlined.
a) NH3
-3
b) H2SO4
6
c) ZnSO3
4
d) Al(OH)3
3
e) Na
0
f) Cl2
g) AgNO3
5
h) ClO4-
7
i) SO2
4
j) K2Cr2O4
3
0
k) Ca(ClO3)2
5
l) K2Cr2O7
6
m) HPO32-
3
n) HClO
1
o) MnO2
4
p) KClO3
5
q) PbO2
4
r) PbSO4
2
s) K2SO4
6
t) NH4+
-3
u) Na2O2
-1
v) FeO
2
w) Fe2O3
3
x) SiO44-
-2
y) NaIO3
5
z) ClO3-
5
aa) NO3-
5
bb) Cr(OH)4
cc) CaH2
ee) Fe(H2O)63+
-1
+3
dd) Pt(H20)5(0H)2+
ff) CH3COOH
4
+3
0
34. What is the oxidation number of carbon in each of the following substances?
a) CO
2
b) C
0
c) CO2
4
d) CO32-
4
e) C2H6
-3
f) CH3OH
-2
35. For each of the following reactions, identify: the oxidizing agent, the reducing agent, the substance
oxidized and the substance reduced.
a) Cu2+ (aq)
+
Zn (s)
-------->
Substance oxidized
Oxidizing agent
b) Cl2 (g)
+
Zn
Cu2+
2 Na (s) -------->
2 Na+ (aq)
Substance oxidized
Oxidizing agent
c)
Al3+ +
+3
Zn
0
Na
→
Substance oxidized Zn
d)
Cr2O72+6
+
Cr3+
+
ClO4+3
+7
Substance reduced
Al
0
Cl2
+
Zn2+ (aq)
Substance reduced
Reducing agent
+
2 Cl- (aq)
Substance reduced
Reducing agent
Zn2+
+2
Cu2+
Zn
Cl2
oxidation numbers!
Oxidizing agent Al3+
ClO2- →
+3
Substance reduced Cr2O72e)
Cu (s) +
→
ClO4-
Cr3+
+3
+
ClO4+7
oxidation numbers
Oxidizing agent Cr2O72Cr2O72- +
ClO2+6
+3
Oxidizing agent
ClO4-
oxidation numbers
f)
O3 + H2O + SO2 → SO42- + O2 + 2H+
?
+4
+6
0
oxidation numbers
Substance oxidized
SO2 Reducing agent SO2
g)
3As2O3 + 4NO3- + 7H2O + 4 H+ → 6H3AsO4 + 4NO
+3
+5
+5
+2
oxidation numbers
Substance reduced NO3Reducing agent
As2O3
Na