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在中和法滴定理论研究中,滴定突跃的研究占有很重要的地位。所谓滴定突跃就是指滴定在等当量点前后微小数量的滴定溶液加入后溶液PH变化的情况。不同类型的中和滴定,其滴定突跃的大小,直接影响到测定结果的准确性。在较好的实验条件下,测定的结果能准确到|△PH|=0.2。如何求出在等当点附近对应不同的△PH所产生的误差百分率(△T)是处理中和滴定理论计算的重要问题。对于解决这个问题,现在一般书中采用计算中和滴定曲线的方法来研究滴定突跃。也就是使用酸碱平衡公式,作一些近似处理,按代数方法计算。这方法对于强酸滴定强碱、强酸滴定弱碱滴定曲线计算的处理比较好。但是对于强碱滴定多元酸、混合酸、弱酸滴定弱碱等类型的滴定突跃的计算问题就很难处理。其次,在用代数方法处理的滴定理论中,有很多重要结论并没有理论证明。例如对于强碱滴定弱酸的滴定条件是CKa≥10_3;强碱滴定二元弱酸分步滴定的条件是K_1/K_2≥10~4或K_1/K_2≥10~5,
In the research of titration theory of neutralization method, the study of titration epoch plays an important role. The so-called titration jump refers to the situation where the pH of the solution changes after the titration solution is added before and after the equivalent point. Different types of neutralization titrations, the size of their titration jerk, directly affect the accuracy of the results. Under better experimental conditions, the result of the determination can be accurate to |ΔPH|=0.2. How to find the error percentage (△T) corresponding to the different △PH near the equal point is an important problem in the calculation of the neutralization titration. To solve this problem, we now use the method of calculating the neutralization titration curve to study the titration jump. That is, using the acid-base balance formula, some approximations are made and calculated by algebraic methods. This method is better for the titration of strong bases with strong acids and the calculation of titration curves for weak bases with strong acids. However, it is difficult to deal with the calculation problem of titration leaps such as strong base titration of polybasic acids, mixed acids, and weak acids to titrate weak bases. Second, there are many important conclusions that have not been proved theoretically in the titration theory of algebraic methods. For example, the titration conditions for titration of weak acids with strong bases are CKa ≥10_3; the conditions for step titration with strong base titrations for dibasic weak acids are K_1/K_2≥10~4 or K_1/K_2≥10~5.