Mechanism of the oxidation of hydroxylamine by ferricyanide

Abstract

The kinetics of the oxidation of hydroxylammonium ion by ferricyanide has been investigated at low hydrogen-ion concentrations (pH 4·2–5·7). Reaction occurs by the interaction between ferricyanide and unprotonated hydroxylamine. The radical NH₃O·first formed is further oxidised except at low ratios for [Fe(CN)₆^3–]₀ : [NH₃OH⁺]₀ where it dimerises and subsequently gives the product. The rate law has been obtained as –d//_dt[Fe(CN)₆^3–]=k[Fe(CN)₆^3–][NH₃OH⁺][H⁺]^–1 with k= 0·69 × 10^–6 l. mole^–1 sec.^–1 at 25 °C.