Product speciation and aquation after the reaction of Cr-51(VI) with concentrated HCl or H2SO4

The present study was undertaken to investigate the reaction of Cr(VI) in c oncentrated hydrochloric acid or concentrated sulfuric acid, as well as to evaluate the products formed when complexing anions are present during the reaction. The results show that trace level Cr(VI) is rapidly reduced to Cr (III) in both 37% HCl and 98% H2SO4 in the absence of conventional reducing agents and that the initial products are, respectively, CrCl3(H2O)(3) and Cr(H2O)(2)(SO4)(2)(-), which undergo slow aquation reactions at pH 1, givin g Cr(H2O)(6)(3+).