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本文从络合物的条件稳定常数出发,通过实验研究认为:在络合反滴定中,所选择的滴定剂金属,其络合物稳定常数应接近被测金属络合物稳定常数。稳定常数再大,无害也无益;过小则不能准确滴定。选择的滴定条件,要使两种金属在该条件下都能独自准确测定。在预络合的酸度下,被测金属一般不应水解。络合剂过量的程度,要保证被测金属预络合完全。指示剂的选择与直接滴定两种金属总量的要求相同。
In this paper, starting from the conditions of the stability constants of complexes, experimental studies show that: in the complexing titration, the selected titrant metal, the stability constant of the complex should be close to the stability of the metal complex measured. Stability constants and then large, harmless is also beneficial; too small can not be accurate titration. Titration conditions selected, so that the two metals in the conditions can be accurately measured alone. In the pre-complexed acidity, the measured metal should generally not be hydrolyzed. The degree of complexing agent overdose, to ensure that the measured metal pre-complexed completely. The choice of indicator and the direct titration of the two requirements of the total amount of metal.