Indicadores ácido-base e titulação: uma proposta experimental investigativa para o ensino de química

Abstract

Daily challenges and problems encountered in Chemistry classes can be summarized in the traditional teaching culture that has been passed down through generations, disinterested students, little active in the teaching and learning process, lack of resources in schools, little exploration of experimental activities and disconnection between theory and the reality of the student. These points listed unfortunately reflect in the difficulties that students have with this scientific knowledge and little appropriation of it. In this work, we emphasize the importance of experiments as great allies for a pedagogical practice in order to promote the student's active role in the face of the proposed challenges. Therefore, the objective was to analyze the process of knowledge construction under the investigative approach in an experiment with students in the first period of the Chemistry Degree course at the Federal Technological University of Paraná, knowing the importance and the richness of including them in science classes. The students worked in groups on a problem situation involving the appropriate choice of an indicator for an acid-base titration, developed their observations, answered initial and final questionnaires and raised hypotheses about the phenomena observed in the titrations under the guidance of the teacher. The students' participation in the titration process was unanimous. They showed interest and curiosity when carrying out the practical work, and discussed differing opinions until they reached a conclusion that was closer to the theoretical one. In their written responses, the students showed remarkable development in the appropriation of their knowledge and in scientific literacy. This activity aims not only to consolidate the theoretical understanding of titrations, but also to develop practical and critical skills in solving a problem, enabling participants to make informed decisions and participate in the teaching-learning process.