标准曲线法测定强碱弱酸盐含量

Content determination of the salt of strong base and weak acid by standard curve method

一般认为弱一元碱的ＣｂＫｂ大于１０－８时可直接用盐酸标准溶液滴定．在ＣｂＫｂ小于１０－８的情况下，根据在溶液中的电荷平衡推导出滴定消耗的酸标准溶液摩尔数与弱一元碱摩尔数之间的线性关系及分析误差△Ｖｅ／Ｖｅ小于１．０％的滴定终点范围，以此为依据提出标准曲线法测定强碱弱酸盐含量的方法．实验结果表明，ＣｂＫｂ大于１０－１２的条件下可以获得满意的结果．

The weak monoacid was generally considered to be able to titrate directly with standard acid solution,when the CbKb of the weak monoacid was more than 10-8.when the CbKb of the weak monoacid was less than 10-8,it was infered that the line relation between mol data of consumed standard acid solution and weak monoalkaline on the basis of charge equilibrium of solution and the range of titration terminal point of the △Ve/Ve<1.0%of analystical error. From that,the method of determing the content of the salt of strong base and weak acid by standard curve met hod was proposed. The experiment showed that the results were satisfactory when the CbKb was more than 10-12 situation.