论文部分内容阅读
高锰酸钾碱液中NaOH的测定,因KMnO_4液呈很深的紫红色,使用一般酸碱滴定法常用的指示剂如酚酞、甲基橙、甲基红等。滴定终点难辩,测定无法进行。本文论述了采用溴百里酚蓝作为滴定指示剂,控制好试液中KMnO_4、指示剂和水的用量,以邻苯二甲酸氢钾标准溶液为滴定剂,终点变化明显,容易观察,使测定成为可能。用该法测定,其精确度可满足生产上的要求。
The determination of NaOH in potassium permanganate lye is very dark purple due to KMnO4 solution. The common indicator of acid-base titration is phenolphthalein, methyl orange and methyl red. Titration end difficult to argue, the determination can not be carried out. This article discusses the use of bromine thymol blue as a titration indicator to control the amount of KMnO_4 in the test solution, indicator and water. With potassium hydrogen phthalate standard solution as a titrant, the end point changes significantly and is easy to observe. become possible. With the method of determination, its accuracy can meet the production requirements.