大学化学 >> 2021, Vol. 36 >> Issue (9): 2012053.doi: 10.3866/PKU.DXHX202012053

所属专题: 分析化学课程与实验教学

化学实验 上一篇    下一篇

高锰酸钾法测定白云石中钙的影响机制探究

向思佳1, 廖光旭1, 姚奇志1,2,*(), 金谷1, 李玲玲1,2   

  1. 1 中国科学技术大学化学与材料科学学院, 合肥 230026
    2 化学国家级实验教学示范中心(中国科学技术大学), 合肥 230026
  • 收稿日期:2020-12-31 录用日期:2021-02-18 发布日期:2021-03-15
  • 通讯作者: 姚奇志 E-mail:qzyao@ustc.edu.cn
  • 作者简介:姚奇志, Email: qzyao@ustc.edu.cn
  • 基金资助:
    安徽省高等学校省级质量工程重点项目(2018jyxm1021);中国科学技术大学研究生教育创新计划教学改革研究项目(2020ycjg04);中国科学技术大学本科质量工程项目(2020xjyxm066);中国科学技术大学本科质量工程项目(2020xy1kc011)

A Study on Influence Mechanism in Determination of Calcium Content in Dolomite by Potassium Permanganate Titration

Sijia Xiang1, Guangxu Liao1, Qizhi Yao1,2,*(), Gu Jin1, Lingling Li1,2   

  1. 1 School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China
    2 National Demonstration Center for Experimental Chemistry Education(University of Science and Technology of China), Hefei 230026, China
  • Received:2020-12-31 Accepted:2021-02-18 Published:2021-03-15
  • Contact: Qizhi Yao E-mail:qzyao@ustc.edu.cn

摘要:

“白云石中钙含量测定”是大学分析化学实验中重要的实验内容之一,学生在进行该实验时发现,用草酸钠标准溶液标定高锰酸钾溶液和用标定过的高锰酸钾溶液滴定由白云石转化形成的草酸钙时,其起始氧化还原反应速度存在明显的差异。针对这些实验现象,结合理论知识,提出了几点猜想,并指导学生设计实验进行探究和验证。通过这些实验探究,不仅解答了学生的疑惑,更重要的是培养和提高了他们分析和解决问题的能力,激发了学生对化学实验学习的兴趣。

关键词: 高锰酸钾法, 氧化还原反应, 草酸钙, 影响因素, 滴定速度

Abstract:

"Determination of calcium content in dolomite" is one of the important experiments in college analytical chemistry laboratory. During the experiment, students found that the initial redox reaction rates are significantly different between the calibration experiment of potassium permanganate solution by sodium oxalate standard solution and the titration experiment of calcium oxalate formed from dolomite by the calibrated potassium permanganate solution. Based on these experimental phenomena and combined with chemistry theory mastered by students, some conjectures and explanations were put forward. After that, we guided students to design experiments to explore and verify them. Through these experiments, it can not only answer the students' doubts, but also train and improve their ability to analyze and solve problems, and thus stimulating students' interest in chemical experiment learning.

Key words: Potassium permanganate method, Redox reaction, Calcium oxalate, Influence factors, Titration rate

MSC2000: 

  • G64