Oxidation of thiocyanate by iron(V) in alkaline medium Academic Article uri icon

abstract

  • The oxidation of thiocyanate (SCN -) by iron(V) (Fe(V)) was studied as a function of pH in alkaline solutions by a premix pulse radiolysis technique. The reaction precedes via a two-electron oxidation, which converts Fe(V) to Fe(III). The rates decrease with an increase in pH. The reactivity of diprotonated Fe(V) species, H2FeO4- with SCN - could account for the decease in rate with increasing pH. The oxidation of thiocyanate by iron(V) (Fe(V)) was studied as a function of pH in alkaline solutions by a premix pulse radiolysis technique. The rates decrease with an increase in pH. The rate law for the oxidation of SCN - by Fe(V) was obtained as -d[Fe(V)]/dt = k 10{[H +] 2/([H +] 2 + K 2[H +] + K 2K 3)}[Fe(V)][SCN -], where k 10 = 5.72 ± 0.19 × 10 6 M -1 s -1, pK 2 = 7.2, and pK 3 = 10.1. The reaction precedes via a two-electron oxidation, which converts Fe(V) to Fe(III). Thiocyanate reacts approximately 10 3× faster with iron(V) than does with iron(VI). © 2004 Elsevier B.V. All rights reserved.

author list (cited authors)

  • Sharma, V. K., O’Connor, D. B., & Cabelli, D.

citation count

  • 17

publication date

  • December 2004