Abstract: Vitriols, such as potassium alum, green vitriol, and blue vitriol, have been used in various aspects of human life and chemical practices for centuries. This article guides readers through a story exploring the diverse roles of these substances in water purification, food processing, sterilization, dyeing, acid production, and medicine. It highlights the chemical reactions involved and the potential hazards of improper use. Through this exploration, readers will gain an understanding of vitriols and their significant impact on society, illustrating the close relationship between chemistry and everyday life.

Key words: Popularization of science, Potassium alum, Green vitriol, Blue vitriol