Chemistry 40S Electrochemistry Problem Set: Redox Reactions
Electronegativity Trends
1. Place the following fictitious elements on the periodic table in a unique pattern that demonstrates
the general trend in increasing electronegativities so that no two elements are located directly
beside each other on the table. (2 marks)
Relative Electronegativities
Ey<Sa<Ju<Zk
Assigning Oxidation Numbers
2. Write oxidation numbers in round brackets above each atom in the following chemical formulas.
Show the algebra you used to arrive at your answer below the formula. A sample solution is
provided. (4 marks)
( 1) ( 2 )
H2 O
2 ( 1)( 2 ) 0
BaO2
Na4Si2O4
I3–
Identifying Oxidizing and Reducing Agents
3. Write oxidation numbers above each atom and circle and label the strongest oxidizing agent (SOA)
and the strongest reducing agent (SRA). You do NOT have to balance the equation. (2 marks)
AuCl4–(aq) + H2(g) Au(s) + Cl–(aq) + H+(aq)
Writing Balanced Net Ionic Equations
4. Write the balanced net ionic equation when an aluminum strip reacts in a solution of copper (II)
sulfate. (3 marks)
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Chemistry 40S Electrochemistry Problem Set: Redox Reactions
Writing Balanced Equations from Half Reactions
5. Given the following half-reactions, write the balanced net ionic equation. (2 marks)
Reduction ½ reaction: ClO2 + e–  ClO2–
Oxidation ½ reaction:
2Hg + 2Cl–  Hg2Cl2 + 2e–
Making a Redox Table
6. Create a redox table of half reactions from the following experimental results. Write all half
reactions as balanced reduction half reactions with the strongest oxidizing agent (SOA) located at
the top left hand side of the list. (3 marks)
Sv(s) + Mc+(aq)  Sv2+(aq) + Mc(s)
St2+(aq) + Mc(s) Mc+(aq) + St(s)
Dk3+(aq) + Sv(s) No Reaction
Reading the Redox Table
Use the redox table below to answer the next two questions.
Reduction ½ Reaction

Ered
(Volts )
Fe3+(aq) + 3e–  Fe(s)
IO4–(aq) + 2H+(aq) + 2e–  IO3– (aq) + H2O(l)
La3+(aq) + 3e–  La(s)
ClO2(g) + e–  ClO2–(g)
AgCl(s) + e–  Ag(s) + Cl– (aq)
–0.04
+1.60
–2.37
+0.95
+0.22
7. Write the balanced equation that includes the strongest oxidizing and reducing agents. (2 marks)
8. Could a solution containing iron (III) ions be stored in container containing Lanthanum without
contaminating the solution? Explain your reasoning. (2 marks)
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