碘量法测定铜盐中铜质量分数实验的改进

分析实验"铜盐中铜质量分数的测定"采用的是间接碘量法,在实际测定中为减小吸附带来的测定误差需加入一些辅助试剂,这又导致了环境污染和终点颜色的难以判断等.为解决这一矛盾提高测定的准确度,用正丁醇作萃取剂萃取碘,碘自身作指示剂,对间接碘量法测定铜盐中铜质量分数实验进行了改进.终点有机相颜色由I2的棕红色变为无色,变色非常敏锐,精密度好,准确度高,加标平均回收率在98.50%~99.25%,结果令人满意.

An experiment improvement of iodometric determination of copper content in copper salts

Indirect iodimetry is utilized to determine the percentage of copper in cupric salt in current analytical chemitry experiment manul.In this method,auxiliary reagents need to be added to decrease the error from the adsorption effect.However,these auxiliary reagents can cause environmental pollution and make the determination of the final color difficult.To resolve the two problems,n-butanol was used to extract iodine and the color of iodine in the n-butanol was employed as indicator.In this new methodology,the final organic phase is colorless,which is much easier to be determined than the brown one of the previous method.Consequently,the accuracy is improved.Furthermore,the recoveries in standard addition is in the range of 98.50 %~99.25 %,which is satisfactory.