A Green Chemistry Laboratory Kit Utilizing Natural Indicators to Enhance Students’ Science Process Skills in Cr(VI) Detection

Despite its critical role in promoting safe, environmentally conscious, and sustainable laboratory practices, the integration of green chemistry principles in secondary school chemistry education remains limited. This study developed and evaluated a green chemistry-based laboratory kit for detecting hexavalent chromium [Cr(VI)] using a natural indicator extracted from mulberry fruit ( Morus nigra L.) to enhance students’ science process skills (SPS). A quasi-experimental design involved two grade 10 classes (n = 40 students) at an Islamic senior high school in Indonesia. The control group used conventional synthetic reagent (1,5-diphenylcarbazide), while the experimental group used the developed kit. Data were collected through pretests, posttests, and structured observations. The experimental group achieved average SPS scores of 85 ± 6% (Good category) with N-Gain of 0.76 ± 0.13, while the control group scored 64 ± 3% (Fair category) with N-Gain of 0.34 ± 0.12 ( p < 0.001). Integrating green chemistry principles into laboratory learning significantly improved students’ SPS and strengthened their awareness of sustainability and safety. This laboratory experiment demonstrates high potential as an innovative educational tool for secondary chemistry education.