This study explores the integration of STEM principles into chemistry education through the redesign of the topic Chemical Reactions for initial teacher training. The aim was to develop and evaluate an innovative teaching module that fosters key competences--knowledge, skills, and attitudes--via student-centred, context-based, and interdisciplinary approaches. The research followed a design-based methodology, involving the development, implementation, and iterative refinement of teaching materials. Data were collected through textbook analysis, classroom observations, and pilot feedback from pre-service teachers. Key features of the module include experimental reaction cycles, real-life applications, and the use of digital tools. The findings show that this approach enhances students' conceptual understanding, motivation, and ability to connect chemistry with real-world issues such as sustainability and materials design. The module promotes inclusive and engaging science teaching and serves as a replicable model for other curriculum topics. It also supports the preparation of future teachers for competence-oriented and interdisciplinary education. [For the complete proceedings, see ED673688.]