A mathematical expression has been developed describing the change in thermodynamic free energy for a chemical system as a function of time to aid the interpretation of experimental time-dependent energy curves, such as the open circuit potential (OCP) plots, generated in corrosion studies. Accurate results of chemical potentials and reaction rates, one pair of constants for each causal chemical reaction, were found. Reaction rate constants were determined for OCPs of Fe(CN)(6)(-2) + 1/2I(2) --> Fe(CN)(6)(3-) + I- at room temperature of omega(1) = 0.011 +/- 0.002/s, for oxidation of Fe(CN)(6)(4-) to Fe(CN)(6)(3-) and omega(2) = 0.108 + 0.003/s for reduction of I-2 to I-, and the known half-cell potentials were reproduced. Experimental aluminum dissolution OCP data was fit using regression analysis describing a four to ten chemical reaction model. The formalism was useful in describing results of OCP plots of integrated circuits (IC) interconnect metals, cleaned by fluoride-based silicon wafer remover formulas, in terms of identifying the causal corrosion chemistry. (C) 2004 The Electrochemical Society.