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本文讨论了以下几个问题: 1.结合本文研究的亚铊和硫氰酸根在不同pH时的络合反应,讨论了微溶盐M_nL_m在配位体A的水溶液中,在不同的pH值下,M能与A、L、OH分别作用而生成单核、多核和混合型络合物时,利用溶解度S的实验数据求络合物稳定常数的一般处理方法。 同时也讨论了由于将C_A代替(A)而引起的误差的校正方法。 2.在保持离子强度为2.50(NaClO_3为支持电解質),配位体最大浓度为2.0M,温度为18°、25°、30°±0.05℃,pH为7.50、8.50、9.50、10.50、11.50、12.00、12.30、12.48、12.60、12.70时,利用上述计算方法,重新研究了亚铊——硫氰酸根——氢氧根体系,结果得到TIOH、Tl(SCN)_n(n=1、2、3、4,5)和混合型络合物Tl(SCN)_n(OH)(n′=1、2、3,4)三类络合物,其稳定常数依次为:25℃:K_(1,0,1,0)=2.08;K_(1,0,2,0)=4.77;K_(1,0,3,0)=4.07; K_(1,0,4,0)=3.01;K_(1,0,5,0)=0.39。 K_(TIOH)=0.80;K_(1,0,1,1)=1.47;K_(1,0,2,1)=4.45; K_(1,0,3,1)=4.15;K_(1,0,4,1)=2.38。 同时也计算了此络合反应在不同pH值下,在不同配位休浓度时溶液中各种络离子的百分组成和(?)。
In this paper, the following issues are discussed: 1. Combined with the complexation reaction of thallium and thiocyanate at different pH in this paper, it is discussed that the sparingly soluble salt M_nL_m in the aqueous solution of ligand A, at different pH , M can react with A, L, OH to form mononuclear, multinuclear and mixed complexes, respectively, using the experimental data of solubility S to find out the general method of stabilizing the complex. The method of correcting errors due to replacing C_A with (A) is also discussed. 2. While maintaining the ionic strength of 2.50 (NaClO_3 as supporting electrolyte), the maximum ligand concentration was 2.0 M, the temperature was 18 °, 25 °, 30 ° ± 0.05 ° C, pH was 7.50,8.50,9.50,10.50,11.50 , 12.00,12.30,12.48,12.60,12.70, the thallium-thiocyanate-hydroxide system was revisited using the above calculation method, resulting in TIOH, Tl (SCN) _n (n = 3,4,5) and mixed complex Tl (SCN) _n (OH) (n ’= 1,2,3,4). The stability constants were as follows: 25 ℃: K_ , K (1,0,2,0) = 4.77; K_ (1,0,3,0) = 4.07; K_ (1,0,4,0) = 3.01; K_ (1,0,5,0) = 0.39. K_ (TIOH) = 0.80; K_ (1,0,1,1) = 1.47; K_ (1,0,2,1) = 4.45; K_ (1,0,3,1) = 4.15; K_ (1, 0,4,1) = 2.38. At the same time, the complex composition and (?) Of various complex ions in solution at different pH values were also calculated.