A sustainable chemical garden for secondary chemistry education

Abstract

Chemical gardens are valuable resources for experimental chemistry teaching because they enable the visual exploration of phenomena such as precipitation, solubility, osmosis, and self organization. However, their use in school settings is often limited by the employment of potentially toxic metal salts, their cost, and the management of the resulting waste. This paper presents a sustainable adaptation of the experiment designed for secondary
school students, in which conventional metal salts are replaced with magnesium sulfate and commercial silica gel is used as a porous support, together with water-soluble food dyes. The proposal preserves the visual and conceptual interest of the phenomenon while improving its safety, accessibility, and feasibility in the school laboratory. The paper discusses its value as a teaching resource for promoting observation and the interpretation of physicochemical processes in secondary education.