Problem set # 7
Chemistry 200
Redox Reactions
Name:
1. In the reactions
a) 3Fe + 4H2O  Fe3O4 + 4H2
b) 2Al + 3Zn2+  2Al3+ + 3Zn
c) 2KBr(aq) + Cl2(aq) → 2KCl(aq) + Br2(l)
Which species are oxidized and which are reduced? Which species are the oxidizing agents
and which are the reducing agents?
2. Find the oxidation state (oxidation number) for each element in the following
molecules/ions.
a) N in (NH4)3PO3?
b) O in MgSO4?
c) C in C6H10O2?
d) S in HSO4-?
3. Given the unbalanced equation below:
Fe3O4(s) + 4H2(g) → 3Fe(aq) + 4H2O(g)
a. identify the oxidation state of each element
Dr. Behrang Madani
Chem 200
IVC
b. identify the oxidizing agent
c. identify the reducing agent
4. Blance each chemical equation using half-reactions method.
a) Fe2+ + MnO4-  Fe3+ + Mn2+
b) Cr2O72-(aq) + HNO2(aq)  Cr3+(aq) + NO3-(aq)
c) I3- + S2O32-  I- + S4O62-
Dr. Behrang Madani
Chem 200
IVC