Formation of chromium(V)-lactic acid complex in the chromic acid oxidation of lactic acid

Oxidation of lactic acid proceeds in two steps; the first step leads to the formation of chromium(III) and to an unusually stable chromi um(Y) intermediate complex whereas the second step penains to reduction of the latter to chromium(III) as the final product. Kinetics of formation of the stable chromium(V) lactic acid complex has been studied by spectrophotometry. The reaction has been found to be second order in [lactic acid]. Chromium(Y) complex reacts with lactic acid in a slower manner than does chromium(YI). Under specific acid concentrations the two steps can be separated and investigated individually.