酸碱滴定终点误差分析pdf.pdfVIP

·68 · 杨伟群等 ,酸碱滴定终点误差分析 Vo l. 29. No. 1, 2007 酸碱滴定终点误差分析 杨伟群 (台州职业技术学院 生化系 ,浙江 台州 3 18000) 摘要 :为了减少酸碱滴定利用指示剂变色来确定滴定终点的误差 ,提高分析测定结果的准确度 。通过理论分析和实例分 析 ,对酸碱滴定中不同的指示剂 、不同浓度的被测物质进行了分析讨论 ,并根据溶液物料平衡和电荷平衡关系 ,直接推导得出 酸碱滴定终点误差公式 。对确定分析样品的取样量 ,选用适合浓度的试剂及适当的指示剂 ,减少滴定终点误差 ,提高分析结 果的准确度具有指导意义 。该方法易于理解和掌握 ,对酸碱滴定终点误差分析和计算具有指导意义 。 关键词 :酸碱滴定 ;指示剂 ;浓度控制 ;终点误差 ;公式推导 中图分类号 : TQ 42 1. 32　　　　　文献标识码 : A 　　　　　文章编号 : 100 1 - 00 17 (2007) 01 - 0068 - 04 A nalysis of the Endpo in t Error in A cid - ba se Titration YAN G W ei - qun (D ep a rtm en t of B iolog ica l Chem ica l Eng ineering, Ta izhou Voca tiona l Techn ica l Colleg e, Ta izhou 318000, Ch ina) Abstract: In order to reduce the endpoint error w ith indicator in acid - base titration , to imp rove the accuracy of exp erim ental resu lts, the effects of indicator, and the concentration of the sub stance wh ich wou ld be determ ined on endpoint error were studied w ith theoretical analysis and actual examp les. The endpoint error formu la was deducted according to m aterial balance and charge balance. It was help fu l for determ in ing the amount of the samp le, selec ting the agent w ith p rop er concentration and indicator, reducing the endpoint error and imp roving the resu lt of the analysis. Th ism ethod was conven ient to understand and handle, and it was u sefu l for analysis and calcu lation of endpoint error in acid - base titration. Key words: A cid - base titration; indicator; concentration control; endpoint error; deduction of formu la ( ) ( )