A kinetic study of the reaction between octacyanomolybdate(V) and iodide ions

Abstract

The rate of the reaction between octacyanomolybdate(V) and iodide has been measured by a microtitration method. The orders with respect to Mo(CN)₈^3– and I^– are a little larger than unity. Mo(CN)₈^4– has a retarding effect. The reaction exhibits very specific salt effects in the order : (Et₄N⁺ Li⁺ < (C₂H₄OH)₄N⁺≃ Na⁺ < K⁺ < Mg⁺⁺ < Ca⁺⁺ < Ba⁺⁺. The Olson–Simonson rule is approximately obeyed, but some specific effects due to anions are also present. A probable reaction mechanism is discussed.