Uma proposta de estudo de caso no ensino de Química: usar gasolina ou etanol como combustível?

Abstract

The case study methodology based on Problem-Based Learning (PBL) was used as a didactic proposal in teaching chemistry through a socio-scientific theme discussing the concepts of thermochemistry and energy. We structured a case called “Should I use gasoline or alcohol (ethanol)?, which raises a problem-situation about which fuel the consumer should use as fuel. The proposal was applied in the chemistry class of the 4th period of the integrated technical course in food at IFPE Campus Barreiros. As an analysis tool, we used questionnaires before and after the application of the case, in order to verify some of the students' perceptions regarding chemistry classes, the participation of their colleagues during teamwork, the importance of chemistry for their lives, the difficulties to resolve the case, among other issues. The analysis of the reports prepared by the groups was also carried out with the purpose of analyzing the positioning of the groups. The results showed that the proposed case brought an interesting and stimulating vision of learning chemistry with 77.8% of students stating that they would like to take more chemistry classes with the case study methodology in their daily lives. Analysis of the reports indicated that students were able to apply the concept of yield (energy per liter) to understand the economic issue when choosing between alcohol and gasoline. In relation to environmental aspects, the groups were able to evaluate issues involving renewable energy sources, environmental pollution and sustainability. The proposed case brought critical and reflective learning that contributed to the students' ability to argue, problem solve and make decisions