AN EXPERIMENT UTILIZING ROSELLE FOR ASSESSING GROUNDWATER QUALITY IN AN ENVIRONMENTAL CHEMISTRY CONTEXT FOR GENERAL CHEMISTRY 2 STUDENTS AT LOEI RAJABHAT UNIVERSITY

Abstract

               This research, titled "An Experiment Utilizing Roselle for Assessing Groundwater Quality in Environmental Chemistry Learning for General Chemistry II Students at Loei Rajabhat University", aims to investigate the use of roselle in testing groundwater quality and compare learning outcomes before and after employing roselle to assess groundwater quality and analyze ferric ion presence. Anthocyanin, known for its sensitivity to color changes when interacting with iron ions, was selected for this experiment. Additionally, the integration of smartphones in chemical detection has gained significant interest due to their ability to capture images and process data quickly. Smartphones can be utilized to analyze color changes in solutions that correspond to ferric ion concentrations, simplifying the detection process and making it applicable in diverse settings. The study utilized an experimental research methodology with a sample group of 30 General Chemistry II students. The experiment involved preparing groundwater samples with various ferric ion concentrations (0.5, 1.0, 2.0, 5.0 ppm), extracting anthocyanin from roselle by boiling, mixing the anthocyanin extract with groundwater samples, and measuring the color intensity of the solutions using a smartphone. A UV-Visible spectrophotometer was also employed to measure the absorbance of the solutions. The study assessed learning outcomes by conducting pre- and post-tests to gauge students' knowledge. The results indicated that using anthocyanin from roselle in conjunction with a smartphone effectively measures color intensity, which correlates with ferric ion concentration. A linear relationship was observed between color intensity and ferric ion concentration. Smartphone results were highly correlated with absorbance values from the UV-Visible spectrophotometer, demonstrating the practicality of the proposed method for teaching. In terms of learning outcomes, post-test scores (mean 25.60) showed a statistically significant improvement at the .05 level compared to pre-test scores (mean 5.23), suggesting the experiment improved students' understanding and interest in environmental chemical measurement and analysis. This research underscores the benefits of using anthocyanin from roselle and smartphones for detecting ferric ions in groundwater, offering a cost-effective, convenient, and environmentally friendly method. The use of smartphones as measurement tools reduces the complexity and cost of laboratory sample analysis, making environmental chemistry more accessible. Students can perform experiments and view results immediately.