Replacement of Time with an Area Variable

In 1950 French and Wideqvist independently described a data treatment that makes use of the area under the concentration-time curve, and later authors have discussed the method.We introduce the technique by considering the second-order reaction of A and B, for which the differential rate equation is 

the technique consists of a transformation from the time differential dt to the area differential dQ, and the essential effect of this transformation is a reduction by one of the apparent order of the reaction. The variable 6 is the area under the curve of Cb vs. time from t = 0 to time t. With modem computer techniques for integrating experimental curves, this method should be attractive. 

The treatment will depend upon the chemistry of the system and upon whieh concentrations can be followed. Suppose Cb is accessible. Using the definition of Eq. (3-57) converts Eq. (3-62) to 

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