大学化学 >> 2023, Vol. 38 >> Issue (12): 257-261.doi: 10.3866/PKU.DXHX202305023

化学实验 上一篇    下一篇

比色法测碘酸铜溶度积常数实验的改进

丁子都1, 雷英杰1, 梁云1, 李襄宏1,*(), 王炎英2, 黄涛1   

  1. 1 中南民族大学化学与材料科学学院, 武汉 430073
    2 中南民族大学实验教学与工程训练中心, 武汉 430073
  • 收稿日期:2023-05-08 录用日期:2023-06-06 发布日期:2023-08-17
  • 通讯作者: 李襄宏 E-mail:lixhchem@mail.scuec.edu.cn
  • 基金资助:
    中南民族大学2019年教学改革重点项目(JYZD19057);教育部民族院校应用化学专业虚拟教研室建设经费(XNYJS2202)

Improvement in Colorimetric Detection of the Solubility Product Constant of Copper(Ⅱ) Iodate

Zidu Ding1, Yingjie Lei1, Yun Liang1, Xianghong Li1,*(), Yanying Wang2, Tao Huang1   

  1. 1 School of Chemistry and Materials Science, South-Central Minzu University, Wuhan 430073, China
    2 Experimental Teaching and Engineering Training Centre, South-Central Minzu University, Wuhan 430073, China
  • Received:2023-05-08 Accepted:2023-06-06 Published:2023-08-17
  • Contact: Xianghong Li E-mail:lixhchem@mail.scuec.edu.cn

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摘要：

现行教材中以氨水做显色剂，比色法测定碘酸铜溶度积常数，有一定的环境污染。本实验以甘氨酸替代氨水作为显色剂，通过紫外-可见吸收光谱考察甘氨酸与铜离子反应的时间以及甘氨酸的最佳用量，从而获得配制甘氨酸合铜(Ⅱ)溶液的最佳条件，进而测定该条件下配制的各溶液的吸光度，最终获得碘酸铜饱和溶液中铜离子的浓度并计算得到与文献值接近的溶度积常数。该实验可避免实验过程中挥发性腐蚀性气体的释放，且溶液可浓缩回收甘氨酸合铜(Ⅱ), 避免了环境污染，是一种绿色实验方法，在人数众多的基础实验教学中具有适用性。

关键词: 碘酸铜, 溶度积常数, 比色法

Abstract:

In recent studies, ammonia, a chromogenic reagent, has been used to detect the solubility product constant of copper(Ⅱ) iodate via colorimetry. However, the use of ammonia can result in environmental pollution. As an alternative, glycine can be used as the chromogenic reagent. In this study, the reaction between glycine and copper(Ⅱ) ions was investigated in detail. The reaction time and glycine concentration were optimized by acquiring UV-Vis spectra, determining the appropriate conditions for reacting the copper(Ⅱ) complex with glycine. The absorption intensities at 640 nm for solutions of copper(Ⅱ) ions at different concentrations were measured, and the concentration of copper(Ⅱ) ions in saturated copper(Ⅱ) iodate was determined by using the standard curve. The solubility product constant was calculated, which was close to the literature value. The release of corrosive and volatile gas was prevented in this experiment, and the complex solution could be recycled to prevent environmental pollution. Therefore, this method is green and applicable for use in basic experimental teaching activities.

Key words: Copper(Ⅱ) iodate, Solubility product constant, Colorimetry