A Mystery Game Activity to Enhance Understanding of <i>E</i> –pH Diagrams

E–pH diagrams, also known as Pourbaix diagrams, provide a visual and efficient means of understanding and predicting the behavior of elements and their derived species as a function of the pH and the potential of the medium. However, grasping the theoretical foundations underlying these diagrams and applying them in practice can be challenging for students. Herein, we describe the design and implementation of an educational activity aimed at reinforcing learning through the cognitive-level learning strategy summarized in Johnstone’s triangle and leveraging affective and motivational aspects of gamification. Students were placed in the role of assistants to a forensic police research team tasked with solving two criminal cases. To do so, they had to investigate the acid–base behavior of three cations when increasing the pH of the solution and the redox behavior of three metallic materials. Throughout the investigation, students used Pourbaix diagrams of these substances and confronted their misconceptions regarding the application and conceptual basis of the diagrams. The results showed a significant improvement in short-term learning and a more moderate improvement in the medium term. From an affective perspective, students reported a positive shift in their attitudes toward learning.