Strengths of Oxidising and Reducing Agents - QS Study
top logo

Standard electrode potentials are useful in determining the strengths of any oxidising and reducing agents under standard-state conditions.

– A reduction half-reaction has the general form

oxidised species + ne → reduced species

The oxidised species acts as an oxidising agent. Therefore the strongest oxidising agents in a table of standard electrode potentials are the oxidised species corresponding to the half-reactions with the largest (most positive) E° values. These reactions will have a strong tendency to go from left to right.

For example F2 (g):

F2 (g) + 2e → 2F E° = 2.87V

oxidised species + ne → reduced species

– An oxidation half-reaction has the general form

reduced species → oxidised species + ne

The reduced species acts as a reducing agent. As standard electrode potential tables are always written with respect to reduction potentials, the strongest reducing agents in a table of standard electrode potentials are the reduced species (on the right) corresponding to the half- reactions with the smallest (most negative) E0 values.

For example Li+ (aq):

Li+ (aq) + e → Li (s)