Marshall-Frank equation

Shown in Figure 18.9 is a comparison of ArH° obtained from calorimetric measurements (solid line) and ATH° obtained from the Marshall-Frank equation,15 which is an expression relating K to T that gives ArH° from (dinK/dT)p. The agreement between the two methods is another example of thermodynamic consistency. 

Figure 18.9 AtH as a function of temperature for the association reaction H+(aq) -I- OH (aq) = H20(1). The solid line gives the values obtained from calorimetric measurements and the dashed line gives the values obtained from the Marshall-Frank equation.

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