POURBAIX DIAGRAM Meaning and
Definition
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A Pourbaix diagram, named after the Belgian engineer Marcel Pourbaix, is a graphical representation that depicts the stability regions of various chemical species in an electrochemical system at different pH values. It is commonly used in the field of corrosion science and electrochemistry to determine the conditions under which a particular metal, compound, or element is stable, and to predict the behavior of a system under different pH and potential conditions.
In a Pourbaix diagram, the x-axis represents the electrode potential (expressed in volts) while the y-axis represents the pH of the solution. The diagram is divided into different regions that correspond to different stable chemical species or phases. Each region is often represented by different colors or shading to distinguish between them. By interpreting the diagram, one can determine which species would be stable under a given pH and potential condition.
The stability of a species is indicated by its position relative to the equilibrium line of the system, known as the equilibrium potential (EpH). The diagram also shows lines of equal potential (iso-potential lines) and equal pH (iso-pH lines) to aid in the analysis of the system's behavior.
Pourbaix diagrams serve as valuable tools in understanding the corrosion behavior of metals and designing electrochemical systems. They help in determining the most suitable conditions for the protection of metals and alloys from corrosion, as well as predicting the formation of different corrosion products and their stability in a given environment.
Etymology of POURBAIX DIAGRAM
The word "Pourbaix diagram" is named after Marcel Pourbaix, a prominent Belgian electrochemist who played a significant role in the field of corrosion science. Marcel Pourbaix developed a graphical representation known as the Pourbaix diagram or potential-pH diagram, which provides information about the stability of different chemical species in an aqueous solution at various pH and electrode potentials. These diagrams are widely used in the study of corrosion, electrochemistry, and metallurgy.
