大学化学 >> 2024, Vol. 39 >> Issue (10): 283-288.doi: 10.12461/PKU.DXHX202404068

所属专题： 化学实验教学和管理(2024)

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实验设计的合理性考察与探析——以高锰酸钾和溴化钾的反应为例

魏海英, 杨大清, 闰明涛, 霍国燕   

  1. 河北大学化学与材料科学学院, 化学国家级实验教学示范中心(河北大学), 河北 保定 071002
  • 收稿日期:2024-04-10 录用日期:2024-07-04 发布日期:2024-10-22
  • 通讯作者: 霍国燕 E-mail:guoyanhuo.cool@163.com
  • 基金资助:
    河北省研究生教育教学改革研究项目(YJG2024008)；河北大学第十批教育教学改革研究项目(2023XJJG010)；河北大学课程思政教学改革研究项目(KCSZJG202342)

Examination and Analysis on Rationality of Experimental Design: Based on Reaction of Potassium Permanganate with Potassium Bormide

Haiying Wei, Daqing Yang, Mingtao Run, Guoyan Huo   

  1. National Demonstration Center for Experimental Chemistry Education (Hebei University), College of Chemistry and Materials Science, Hebei University, Baoding 071002, Hebei Province, China
  • Received:2024-04-10 Accepted:2024-07-04 Published:2024-10-22
  • Contact: Guoyan Huo E-mail:guoyanhuo.cool@163.com

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摘要： 合理的实验设计能使学生根据实验现象更好地理解化学原理。分别在实验教材相同体系和不同的pH值范围内对“高锰酸钾和溴化钾的反应”实验的步骤进行考察，结果表明：在pH=1.95–0.98范围内，溴化钾还原高锰酸钾分两步进行，并且还原产物受溶液pH的控制；pH为1.21是第二步自发进行的临界点，接近于理论值1.36。据此对酸度影响反应速度的验证实验给予两点建议，来进一步完善实验设计。

关键词: 氧化还原反应, 高锰酸钾, 溴化钾, 分步还原, 酸度

Abstract: A well-designed experiment allows students to better understand chemical principles through observable phenomena. This study investigates the reaction between potassium permanganate and potassium bromide under two different conditions: identical setups as found in standard textbooks and varying pH ranges. The results indicate that potassium bromide reduces potassium permanganate in two distinct steps in the pH range 1.95–0.98, with the reduction products being influenced by the pH of the solution. The critical pH for the spontaneous occurrence of the second step is 1.21, which is close to the theoretical value of 1.36. Based on these findings, two recommendations are provided to further refine the experimental design by verifying the impact of acidity on reaction rates.

Key words: Redox reaction, Potassium permanganate, Potassium bromide, Stepwise reduction, Acidity