摘要
SnCl_2-TiCl_3-KMnO_4滴定分析法测定铁矿石中铁,用常量分析仪器进行半微量试验,考察了不加入指示剂以及分步加入指示剂对终点颜色判断的影响以及对测定铁含量的结果的影响。结果表明,用量为常量的1/2,1/4时,在接近终点时加入指示剂,终点颜色变化明显,结果无显著性差异;不加入指示剂和滴定前加入指示剂,终点颜色变化不易把握,测定结果偏高,实际用量为常量的1/2无显著性差异,1/4有显著性差异。改进后的试验敏化了终点观察,在化学实验教学中具有很大推广价值。
With the measurement of the iron content in iron ore by SnCl2-TiCl3-KMnO4 titrimetric analysis,and semimicro experiment carried out by constant quantity instrument,the effect of no indicator or fractional indicator on the judge of end point color and the measurement results of iron content are observed.According to the experiments,results show little difference with distinct change of end point color when adding the half or quarter dosage of constant near the end. The measurement is on the high side and the change of end point color is difficult to observe when adding no indicator,or adding indicator before titrimetric operation.There is no distinct difference when reducing the dosage by half,while the difference is distinct when reducing the dosage to a quarter. The improved experiment sensitizes end point observation which is worthy of promotion.
出处
《湖北第二师范学院学报》
2017年第8期1-7,共7页
Journal of Hubei University of Education
关键词
高锰酸钾法
铁矿石
半微量
改进
potassium permanganate method
iron ore
micro-scale titrate
improvement
