The reaction kinetics of CO2 with monoethanolamine is of industrial significance with respect to both CO2 sequestration applications and characterizing the effective interfacial mass transfer area of packed separation columns. Reaction kinetic data were previously, by necessity, only measured under pseudo-first-order conditions with respect to CO2. Furthermore, mass-transfer limitations encountered by the heterogeneous techniques restricted the validity range of the reaction kinetic models developed from the data. New reaction kinetic data, independent of mass-transfer limitations and outside pseudo-first-order conditions, are presented. The data, collected via a previously developed novel, in situ FTIR technique, were subsequently compared with the predictions of two widely accepted rate expressions, the power rate law and pseudo-steady-state hypothesis (PSSH) rate law. The expressions were modeled on the data using a novel multiobjective goal attainment algorithm also developed in this study. The PSSH rate law predictions were in closer agreement with the data than the power rate law, but both rate expressions were found to be unable to accurately describe the reaction kinetics of CO2, proving that they should be used with caution outside of the pseudo-first-order conditions of their derivation. It was, therefore, concluded that a rate law able to describe the reaction kinetics for all reaction conditions should include the zwitterion reaction intermediate concentration in its fundamentally derived rate expression(s).