Auxiliary Oxidizing and Reducing Agents

Concept #1:

An auxiliary reducing agent represents an easily oxidized metal such as Zn, Ag, Sn, or Cd that is part of prereduction.   


Concept #2:

An auxiliary oxidizing agent will oxidize the analyte and in the process be reduced as part of the preoxidation stage.


Example #1:

Answer each of the following questions based on the following half reactions:

HALF REACTIONS                       Eo (V)

Cl2 (g)  +  2 e           2 Cl (aq)           + 1.36

l2 (g)  +  2 e              2 l (aq)              + 0.535

Pb2+ (aq)   +  2 e      Pb (s)                   - 0.126

V2+ (aq)  +  2 e         V (s)                      - 1.18

a)  Which is the strongest oxidizing agent?

b)  Which is the strongest reducing agent?

c)  Will I (aq) reduce Cl2 (g) to Cl (g)?