Horvath Attila K, Nagypal Istvan
Department of Physical Chemistry, University of Szeged, Szeged, P.O. Box 105, H-6701, Hungary.
J Phys Chem A. 2006 Apr 13;110(14):4753-8. doi: 10.1021/jp060246b.
The sulfite-chlorine dioxide reaction was studied by stopped-flow method at I = 0.5 M and at 25.0 +/- 0.1 degrees C in a slightly acidic medium. The stoichiometry was found to be 2 SO(3)(2-) + 2.ClO(2) + H(2)O --> 2SO(4)(2) (-) + Cl(-) + ClO(3)(-) + 2H(+) in ClO(2) excess and 6SO(3)(2-) + 2ClO(2) --> S(2)O(6)(2-) + 4SO(4)(2-) + 2Cl(-) in total sulfite excess ([S(IV)] = [H(2)SO(3)] + [HSO(3)(-)] + [SO(3)(2-)]). A nine-step model with four fitted kinetic parameters is suggested in which the proposed adduct *SO(3)ClO(2)(2-) plays a significant role. The pH-dependence of the kinetic traces indicates that SO(3)(2-) reacts much faster with *ClO(2) than HSO(3)(-) does.
在离子强度I = 0.5 M、温度25.0±0.1℃的微酸性介质中，采用停流法研究了亚硫酸盐 - 二氧化氯反应。化学计量关系在二氧化氯过量时为2SO₃²⁻ + 2ClO₂ + H₂O → 2SO₄²⁻ + Cl⁻ + ClO₃⁻ + 2H⁺，在亚硫酸盐总量过量（[S(IV)] = [H₂SO₃] + [HSO₃⁻] + [SO₃²⁻]）时为6SO₃²⁻ + 2ClO₂ → S₂O₆²⁻ + 4SO₄²⁻ + 2Cl⁻。提出了一个包含四个拟合动力学参数的九步模型，其中所提出的加合物SO₃ClO₂²⁻起重要作用。动力学曲线的pH依赖性表明，SO₃²⁻与ClO₂的反应比HSO₃⁻快得多。
