Planejamento Pedagógico Reverso Aplicado ao Experimento “Método da Fronteira Móvel”

Abstract

The number of students enrolled in higher education institutions has increased in recent years, which can be explained by the public policies to expand this sector. However, as in Basic Brazilian education, higher education also presents a scenario full of problems, including dropout. The exact science courses have the worst statistical numbers related to the abandonment, including the courses related to Chemistry. Among the problems, the difficulty of learning and the high degree of abstraction could be highlighted, which can be minimized using instigating experimental activities. In the specific field of electrochemistry, it is verified that students have difficulty understanding and there is a scarcity of materials with different approaches to be used in this theme, other than the assembly of batteries. Regarding the use of experimentation, when discussing concepts of mobility and conductivity of ions in solution, one possibility is the determination of the transport number, which is defined as being the fraction of current transported by each type of ion in solution and can be determined by different methods. Thus, the objective of this work was to implement an experiment to determine the number of transport, based on the reverse pedagogical planning, of a hydrochloric acid solution by the moving boundary method, to be used in experimental disciplines of physical chemistry. The main products generated were the construction of the experimental device and the preparation of an experimental support script for the student. In the development of this work, different results were highlighted than expected, and these situations present themselves as rich opportunities to discuss different subjects related to the theme and that can be promoted by the teacher during classes. Some epistemological challenges brought by students can be overcome or deconstructed through these unexpected situations, and it is important to highlight this aspect. The occurrence of these situations can be provoked, including variables in the script, and can contribute to the stimulation of curiosity and the development of students’ reasoning for problem solving and that the professor evaluates the results of the application and perform a pedagogical retrofit of the experiment.