The absolute value of the rate constant of the liquid-phase reaction SO 5 −. + Fe(II)

An analytical method for monitoring the Fe2+ concentration during liquid-phase sulfite oxidation catalyzed by iron ions is described. The concentration conditions under which the Fe(III)/Fe(II) ratio is uniquely related to the rate constant of the reaction SO 5 −. + Fe2+ are found by computer analysis. The experimental and calculated Fe(III)/Fe(II) ratio data are in agreement at \(k_{(SO_5^{ - \cdot } + Fe^{2 + } )} = 3.2 \times 10^6 1mol^{ - 1} s^{ - 1} \). This is one of the three rate constant values known from the literature, which differ by a factor greater than 70.