在络合滴定中,溶液的酸度是决定终点误差的关键因素之一。酸度不仅会影响条件稳定常数K_(M(?))~′的大小,从而影响滴定突跃的大小,而且会影响指示剂的变色点,从而影响终点与等当点的差值ΔPM的大小。所以滴定的酸度范围就应同时考虑这两个方面的影响进行选择(2),才能达到滴定准确度所允许的误差范围,这样的酸度范围,可以称为最佳酸度范 In complexometric titration, the acidity of a solution is one of the key determinants of endpoint error. The acidity not only affects the size of the conditional stability constant K_ (M) ~), but also affects the size of the titration jump and the color change point of the indicator, thus affecting the difference ΔPM between the endpoint and the equivalence point. Therefore, titration of the acidity range should take into account both the impact of these two options (2), in order to achieve titration accuracy allowed by the error range, so the acidity range, can be called the best acidity range