Fe(Ⅲ)水解过程中无机阴离子的影响作用

THE EFFECT OF INORGANIC ANIONS ON THE HYDROLYSIS PROCESS OF Fe(Ⅲ) SOLUTION

本文通过PO_4^(3-),F^-,SO_4^(2-),Cl^-,NO_3^-和ClO_4^-存在时,0.1mol/l FeCl_3溶液的碱中和曲线的分析对比,说明了用曲线斜率区分滴定曲线为三个区域:(A)自发水解反应;(B)聚合反应;(C)沉淀反应,以及其他阴离子对中和曲线的影响及其规律,指出阴离子对Fe(Ⅲ)溶液中和反应的影响为不同程度的竞争配位,参与聚合及电中和脱稳,使沉淀反应提前等,并与OH^-共同形成Fe—OH—Fe和Fe—L—Fe结构的复合络合物,控制溶液中络合物形态的物理化学性质。与铁络合能力越强的阴离子影响越大,所造成的曲线的偏移也越大。

The basic titrations of 0. lmol/1 FeCl3 solution containing PO43-, F, SO42-, Cl-, NO3- and ClO4- anions respectively were studied. The curves could be divided into three regions. (A)spontaneous hydrolysis, (B)polymerization and (C) precipitation.The effects of anions on neutralization curves were illustrated and discussed. The anions were in competition with OH- for modulation, participating polymerization and electrical neutralization destabi-lization in different degree.One of the results is that the precipitation reaction take place earlier. The anions can form Fe( III) coordinates and polymers with structures of Fe-L-Fe and Fe-OH-Fe and control the physical and chemical property of species in solution. The stronger the complexation, the larger the effects and the deviations of resulting curves presented.