大学化学 >> 2017, Vol. 32 >> Issue (5): 49-54.doi: 10.3866/PKU.DXHX201612006

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氢氧化钾法与硫酸法制备硫酸铝钾的区别探讨

彭敏*(),石建新,王周,赖瑢,李莲云,郑赛利,陈六平   

  • 发布日期:2017-05-08
  • 通讯作者: 彭敏 E-mail:pzheng_04@163.com

The Differences between the Synthesis of Aluminum Potassium Sulfate by Aluminum Foil Dissolved in KOH and in H2SO4

Min PENG*(),Jian-Xin SHI,Zhou WANG,Rong LAI,Lian-Yun LI,Sai-Li ZHENG,Liu-Ping CHEN   

  • Published:2017-05-08
  • Contact: Min PENG E-mail:pzheng_04@163.com

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摘要：

研究了氢氧化钾和硫酸溶解铝箔制备十二水合硫酸铝钾的区别，通过返滴定法测定制备过程中各阶段的铝含量，深入分析了实验过程中的相关物料守恒，发现氢氧化钾法在铝箔溶解阶段由于副反应形成Al（OH）3沉淀，导致最终产率很低，进行搅拌及降低体系浓度可很大程度上提高产率，不过仍低于硫酸法。此外，硫酸法在实验操作上也相对更简捷。因此推荐学生使用硫酸法来制备十二水合硫酸铝钾。

关键词: 氢氧化钾, 硫酸, 十二水合硫酸铝钾

Abstract:

The differences between the synthesis of aluminum potassium sulfate by aluminum foil dissolved in KOH and in H2SO4 were studied. Analysis of the material balance during the entire synthesis process by back titration of aluminum ion told us that the yield of aluminum potassium sulfate was very low due to Al (OH)3 precipitation produced by side reactions during the dissolution of aluminum foil in KOH. Stiring and lowering the KOH concentration could help to promote the yield with the H2SO4 method still showing a higher yield. Besides, the H2SO4 method was easier and more convenient. In summary, the H2SO4 method was recommended for students to carry out the synthesis of aluminum potassium sulfate.

Key words: Potassium hydroxide, Sulphuric acid, Aluminum potassium sulfate dodecahydrate