Kinetics of oxidation of antimony(III) by vanadium(V) in aqueous hydrochloric acid media

Abstract

The oxidation of antimony(III) by vanadium(V) has been studied in aqueous hydrochloric acid media at 25 °C. It follows the rate law (i) where K1 and K2 are the respective equilibrium constants of the Rate =–d[VV]//dt=kK1K2[VO2+][SbIII][H3O+]//(1+K1[H3O+])(K2+[Cl–])(i) reactions (ii) and (iii) and k is the rate constant of the slow step of the reaction. The data suggest [VO2]++ H3O+⇌[V(OH)3]2+(ii), [SbCl5]2–⇌[SbCl4]–+ Cl–(iii) the interaction of the active species [SbCl4]– and [V(OH)3]2+ in the rate-limiting stage followed by the formation of products in a subsequent fast step.