Half-Cell Reactions and Nernst-Equation Calculations

Half-Cell Reactions and Nernst-Equation Calculations 

Five examples are given of the application of the Nemst equation to half-cell reactions. These examples illustrate the influence of ion concentration, pH, precipitate phases, and complex-ion formation on the electrode potential. All of these variables have significance in aqueous corrosion  

The half-cell potential will be -763 mV (SHE) when the activity is unity. An increase in the activity causes the potential to become more positive. The change is shown graphically in Fig. 2.6. 

It is very convenient to introduce the pH as a measure of the hydrogen ion activity since the acidity of solutions is usually expressed in these 

In aqueous solution, the a TT is related to aII+ uct for water, (aQH )(aH+) = 10. Hence, through the activity prod- 

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