Hands-on Contextual Chemistry Experiments Using Local Materials To Enhance Students’ Scientific Understanding at Smp Negeri 42 Samarinda

Abstract

Chemistry concepts at the junior high school level can be difficult to understand when learning is dominated by theoretical explanations and students have limited opportunities to observe scientific phenomena directly. This community engagement activity aimed to introduce contextual chemistry through simple, low-cost experiments using materials that are readily available in the students’ surroundings. The activity was conducted at SMP Negeri 42 Samarinda on 27 July 2026 and involved 60 students from Grades 7, 8, and 9. Grade 7 students investigated simple water filtration using activated carbon, silica sand, zeolite, and gravel; Grade 8 students investigated carbon dioxide formation from vinegar and baking soda; and Grade 9 students investigated acid–base properties using natural indicators prepared from butterfly pea flowers, hibiscus flowers, and turmeric. The program consisted of an opening session, a 10-item pre-test, conceptual presentation, hands-on practical activities, a 10-item post-test, and student appreciation. The pre-test mean score was 45.5, with 60% of students scoring 40, 25% scoring 50, and 15% scoring 60. After the practical activities, the mean score increased to 89.5; 95% of students achieved a score of 90 and 5% achieved 80. The mean score therefore increased by 44 points, equivalent to a 96.70% relative increase. The findings indicate that contextual, hands-on chemistry activities using accessible local materials can improve students’ demonstrated conceptual understanding and stimulate interest in science learning