Experimentação Demonstrativa de Corrosão Como Meio de Aprendizagem da Tabela de Potenciais de Redução

Resumo

Metallic corrosion, a spontaneous material transformation process, is explored in this work as a generative theme for teaching Electrochemistry in high school. Instruction in this area presents challenges due to the abstraction of concepts such as redox and the difficulty students often encounter in interpreting the Reduction Potential Table. The objective of this article is to present a demonstrative experimental sequence, based on Evans’salt-drop experiment, that employs low-cost and readily available materials to promote effective and contextualized learning. The methodology involves applying saline solutions to iron surfaces, using indicators such as phenolphthalein and red cabbage extract to identify pH variations. The results enable the visual identification of anodic and cathodic regions, as well as the demonstration of spontaneous reactions between iron and zinc metals and Cu2+ ions, highlighting the rapid formation of metallic deposits. The identification of compounds through color changes facilitated the correlation between macroscopic observations and submicroscopic processes. Finally, the proposed didactic sequence supports the transition from experimental practice to theoretical understanding, providing a solid foundation for the comprehension of reduction potentials and everyday electrochemical phenomena.