An Enhanced Colorimetric Integrated Rate Procedure for Determining Kinetic Reactant Order Values

An integrated rate colorimetric procedure for determining kinetic reactant order values is described and applied to the reaction between crystal violet and hydroxyl ion. To correctly time this procedure, absorbance measurements are made from the moment that the reactant solutions are combined. A prediction is made of the unrecorded relationship between reactant solution absorbance and reaction time in the interval before the first absorbance value of the test solution is made. To correctly determine absorbent concentration values corresponding to absorbance measurements, a procedure is applied to allow for deviation from Beer’s Law proportionality.