Calculation of Activity Coefficient Using Debye-Huckel Theory

12 CALCULATION OF ACTIVITY COEFFICIENT USING DEBYE-HUCKEL THEORY 

Combining Equations 1.23 through 1.25, an expression for the activity coefficient of an individual ion can be obtained  

Using the definition of the mean activity coefficient (Equation 1.17), the following equation can be obtained to calculate y.  

If the ionic strength is below 0.001 mol kg , the Debye-Hiickel equations for an individual ion can be simplified as follows  

Note that Equations 1.28 and 1.29 represent the Debye-Hiickel limiting law or fist approximation of the theory. 

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