Definition - What does Chemical Potential mean?
Chemical potential is a measure of the capability of a substance to cause either a chemical or electrochemical reaction in its environment, due to its internal chemical energy or external energy. In a chemical system, it is a measure of disequilibrium of reaction products and reactants.
Chemical potential represents the tendency for corrosive reaction and helps determine:
- Corrosion protection system requirements
- Design parameters
- Measurement and monitoring of corrosion
Corrosionpedia explains Chemical Potential
Chemical potential is the indicator of disequilibrium in a chemical system, consisting of reaction products, reactants and other substances. This disequilibrium leads to chemical and electrochemical reaction, which in turn reduces disequilibrium. Ultimately it tends to reach a state of equilibrium.
Chemical potential is important in many areas of chemistry, particularly for electrochemical reactions, such as different forms of corrosion. In electrochemistry, ionic charge does not always tend to move from higher chemical potential to lower potential, but tends to move from higher electrochemical potential to lower potential. The electrochemical potential fully includes all of the forces influencing the ion's motion, but chemical potential excludes electrical forces.
The abstract definition given as effective change in free energy of a substance, for each additional molecule of substance, is more applicable to total (chemical and electrochemical) potential. If two locations on a metal surface have different total potentials, the difference could be due to the potentials related to external forces such as gravitational or electro force fields and due to factors such as density as well as temperature.