<![CDATA[This study aims to develop a voltaic cell practicum guide based on green chemistry and chemoentrepreneurship (CEP) for senior high school (SMA/MA) and to examine its validity and practicality. The study addressed the gap between the demands of the Fase F Chemistry Learning Outcomes and the actual implementation of voltaic cell practicum in three partner schools, which was constrained by limited laboratory tools, materials, and facilities, unmanaged laboratory waste, and the absence of a practicum guide oriented toward a value-added product. This research employed the Educational Design Research (EDR) approach using the Plomp model, covering the preliminary research phase and the prototyping phase, which consisted of self-evaluation, expert review, one-to-one evaluation, and small group evaluation. The guide integrates five relevant green chemistry principles and three chemoentrepreneurship indicators into a single learning device. Validity was assessed by five expert validators using Aiken's V formula, while practicality was assessed through a five-point Likert questionnaire completed by nine students of SMAN 4 Sumbar and analyzed using a percentage formula. Results showed that the guide was categorized as valid, with an overall average Aiken's V of 0.89, covering content (0.88), presentation (0.89), language (0.88), and appearance (0.91) aspects. The practicality test showed an overall average percentage of 93.19%, categorized as very practical, with the highest score on the green chemistry indicator (98.89%) and the lowest on the benefit aspect (90.00%). These findings indicate that the developed practicum guide is valid and practical for voltaic cell learning in SMA/MA.]]>
