The mixed-cell method (MCM) is the most commonly used Eulerian pore-scale model for reactive flow and transport. Two major disadvantages of MCM are its assumptions of (1) pore-level perfect mixing, and (2) the use of arbitrary and inaccurate rate expressions. In a recent collaborative effort with the EMSL, we have successfully addressed the pore-level perfect mixing assumption using high-quality experimental data obtained in the EMSL. In this work, we attempt to address the second most important underlying assumption in MCM: arbitrary and inaccurate rate expressions. These expressions do not account for the shear-dispersion of solutes due to non-uniform velocity profiles at the pore-scale. Since shear-dispersion is one of the key mechanisms responsible for longitudinal dispersion at the macro scale, neglecting it would result in inaccurate macroscopic predictions. Our hypothesis is that this is due to the exclusion of shear-dispersion from the rate expressions in MCM. In this proposal, we have designed a set of micromodel experiments to validate STM under various Peclet numbers, delineate its range of validity, and identify any problems that would guide future research.