大学化学 >> 2025, Vol. 40 >> Issue (11): 409-415.doi: 10.12461/PKU.DXHX202412034

未来化学家 上一篇    下一篇

对硫代硫酸分解产物单质硫沉淀过程的探究——意外的“失败”？

胡浩哲, 张浩宇, 芦昌盛   

  1. 南京大学化学化工学院, 南京 210023
  • 收稿日期:2024-12-02 录用日期:2025-02-10 发布日期:2025-11-21
  • 通讯作者: 芦昌盛 E-mail:luchsh@nju.edu.cn Changsheng Lu
  • 基金资助:
    教育部化学“101计划”——基础化学实验课程建设项目；教育部第三批虚拟教研室建设点——“101计划”基础化学实验课程虚拟教研室；教育部实验教学和教学实验室建设研究项目(SYJX2024-076)

Study on the Precipitation Process of Elemental Sulfur from the Decomposition Products of Thiosulfuric Acid: Is It an Unexpected Failed Experiment?

Haozhe Hu, Haoyu Zhang, Changsheng Lu   

  1. School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
  • Received:2024-12-02 Accepted:2025-02-10 Published:2025-11-21
  • Contact: Changsheng Lu E-mail:luchsh@nju.edu.cn

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摘要： 在“硫代硫酸钠标准液的配制和标定”实验的操作过程中，大一新生因使用了未经稀释的硫代硫酸钠溶液意外在滴定环节产生大量淡黄色沉淀；学生们经过自主探究，重现了实验现象，调控体系pH ≈ 5时制备出较为稳定的硫胶体体系。通过课外文献调研、估算和分析，学生们推断沉淀成分并推测了硫单质的均相成核沉淀过程，提出可以使用硫胶体替代传统Fe(OH)3胶体用于实验教学与课堂演示。

关键词: 硫代硫酸钠, 单质硫沉淀, 硫胶体

Abstract: During the experiment “Preparation and Calibration of Sodium Thiosulfate Standard Solution”, a significant amount of yellowish precipitation was unintentionally formed during the titration process by a freshman, due to the use of undiluted sodium thiosulfate solution. After conducting independent investigations, the students successfully reproduced the observed phenomenon and controlled the system’s pH to approximately 5, thereby preparing a relatively stable sulfur colloid system. Through additional literature research, estimation, and analysis, the students inferred the composition of the precipitate and hypothesized a homogeneous nucleation process for the precipitation of sulfur. Finally, based on their comparison, they recommended using sulfur colloid as a substitute for the traditional Fe(OH)3 colloid in experimental teaching and classroom demonstrations.

Key words: Sodium Thiosulfate, Sulfur precipitation, Sulfur colloid