Lecture Eight covers the following points:-
- Redox reaction
- Types of reactions
- Types of oxidant and reductant
There are a very large number of oxidation reduction reactions that are used as the basis for analytical methods.
For example:
CeCl4 + FeCl2 = CeCl3 + FeCl3
Ce4+ + 4 Cl- + Fe2+ + 2 Cl- =
Ce3+ + 3 Cl- + Fe3+ + 3 Cl-
Ce4+ + Fe2+ = Ce3+ + Fe3+
Ce4+ = Ce3+
Fe2+ = Fe3+
Oxidation Reaction: is the loss of electrons
Reduction Reaction: is the gain of electrons
Oxidation/Redouction reaction is one in which electrons are transferred from one reactant to another.
Red : Reductant
It is an electron donor
OX: Oxidant
It is an electron acceptor
Standard redox potential: Eo
The higher Eo The stronger OX
the weaker Red
Eo of Cl2/Cl- = 1.36 V
Eo of Fe3+/Fe2+ = 0.77 V
Cl2 : OX Fe2+ : Red
2 Fe2+ + Cl2 = 2 Fe3+ + 2 Cl-
An oxidizing agent with a higher potential can oxidize any reducing agent with a lower potential
A reducing agent with a lower potential can reduce any oxidizing agent with a higher potential
E = Eo + 0.059/n log [OX]/[Red]