Equilíbrio químico em lâmpadas halógenas: contribuições de uma sequência didática

Abstract

This research aims to understand the contribution of a didactic sequence, planned under the theme "halogen lamps", to learn the concept of chemical equilibrium by students of the second year of a public school in the city of Alfenas, located in the south of Minas Gerais. In order to do so, we sought to understand how the chemistry teachers participating in this research teach the concept of chemical equilibrium, what its difficulties are in teaching and in order to learn. In order to construct the didactic sequence, we used the interviews with the teachers and also the sequences present in the didactic books approved in the National Program of the Didactic Book for High School, of the year 2015, adopted by the professors of Chemistry. In a first moment the research was developed with (4) four teachers of Chemistry, in three state schools, the interviews were carried out at this stage that allowed them to understand how they teach the concept of chemical equilibrium. After the transcription and analysis of the interviews, a proposal of a didactic sequence to teach this concept was constructed in collaboration with these teachers, taking into account their notes and also the structure offered by the public schools of the city. For the application and validation of the sequence was first worked on a pilot project, with (33) thirty-three students from a second year high school class. After applying the pilot project, it was realized that some changes would be necessary in the sequence, so that the students could better understand the issues related to the reversible reactions and the dynamicity of systems in chemical equilibrium. After these changes were made the sequence was implemented in other (10) ten classes of second year of high school in (2) two participating schools. For data collection, semi-structured questionnaires, field diaries and audiovisual recording were used, and data were analyzed according to Bardin content analysis techniques. As a theoretical reference for learning the constructivist approach was considered and the didactic sequence model was based on Teaching-Learning Sequence, in studies done by Mehéut, which proposes short teaching sequences in a way that can be analyzed according to the learning theory .