Levantamento de modelos mentais para verificação de aprendizagem significativa do conceito de equilíbrio químico em licenciandos em química

Abstract

The concept of equilibrium corresponds to one of the most complex and difficult topics of teaching and understanding in Chemistry. Although different researches has adopted the theme as an object of research and the important contributions already reported in the literature, the learning problems of this concept still seem to be frequent, justifying the importance of the development of this research whose objective was to contribute to the understanding of the factors involved in the learning process of the concept, using as theoretical references the theories of meaningful learning and mental models. For this purpose, the mental models constructed by 14 undergraduate of a public university of the state of Sao Paulo were investigated and analyzed, with the purpose of searching for evidence of learning with a significant character and close to the conceptual model, allowing the learner to assign meaning to the concept and thus explain it, represent it and use it in different situations and at different levels of representational chemistry. Thus, it was sought to verify if knowledge is expressed through its own manifestations, without losing its scientific meaning, or if learning has become predominantly mechanical, through the memorization of its laws and principles, in a disconnected way without the attribution of many meanings, limiting the students to reproduce phrases and statements without the proper understanding, as well as the possible factors that resulted in these learning. Three instruments of data collection were planned and constructed: a questionnaire, a stop motion and a semi-structured interview script. The data were analyzed based on previously defined and categorized guiding elements, being: elements of low complexity (chemical concepts applicable to any chemical transformations) and elements of high complexity (exclusive of the theme). According to our data, the construction of a mental model that resulting in learning of the concept with a significant predominant character seems to involve the need to overcome simplistic visions derived from sensory experiences, purely related to the concrete level and the presence of mental models of the concept chemical reaction considerably developed and adequate, including at the submicroscopic level. That is, to overcome the problems associated with the concept learning process, it is necessary to know what the student already knows, his initial conceptions and his subsumer, which seem to be limiting factors for the construction of a model for the concept of chemical equilibrium capable of allowing the meaningful understanding of this state as dynamic, reversible and simultaneous.