Decomposition potential and Gibbs Free Energy

[sgstudent]

The decomposition potential is always higher than the theoretically determined potential by thermodynamics. E=η+Eeq where E is the decomposition potential, η is the overpotential and Eeq is the theoretically determined potential.

However since the decomposition potential is higher doesn't it mean that the reaction is more spontaneous? Which is opposite to the original meaning of the equation.

 

[gtoguy97]

No, the decomposition potential does not necessarily mean that the reaction is more spontaneous. The decomposition potential simply indicates the amount of energy required to cause a reaction to occur. A reaction may be more spontaneous at a higher decomposition potential, but it could also be less spontaneous. In general, the thermodynamic equilibrium potential is the best indication of the degree of spontaneity of a reaction.