关于用平衡移动法测定有色络合物组成比及表现稳定常数的讨论

The Discussion on the Determination of the Molar Ratio and Stability Constants of Colored Complexes by the Limited Logarithm Method

近年来常见用平衡移动法测定有色络合物组成比及表观稳定常数的报道,一般认为为这一方法是可靠的,因此使用很广。我们认为此法的原理无疑是正确的、但按目前资料所叙述的数据处理和作图方法,可能导致失真的结果,资料对平衡移动法测定有色络合物的组成比所存在的问题作了很好的说明。我们从化学平衡的原理出发,用计算证实:以显色剂的总浓度C_R~。代替平衡浓度[R],用平衡移动法作图所得曲线求络合物的组成比是不准确的,而且求出的稳定常数严重偏低。因此我们提出平衡移动法数据处理和作图的新方法。

In the PaPer,the Limited Logarithm Method to determine molor ratio and stability constant of colored complexes is discussed.If the total concentration of the complexing regent had been used instead of equilibrium concentration,the method would not have given a correct molor ratio of the complex,and negative erros would have occurred on the stability constant.A new drawing and calculating method for the Limited Logarithm Methed to determine molar ratio and stability constant of colored complexes have been Proposed.