Dificuldades de aprendizagem do conteúdo de soluções: proposta de ensino contextualizada

The study of solutions is considered very important to chemist’s education because most of the chemical reactions occur in aqueous medium, being also required to understand other subject such as chemical changes, electrochemical and chemical balance. Nevertheless, it is noticed that many students indicate learning difficulties related to the content of solutions, how to pass among the macro-submicroscopic knowledge levels, and how to solve quantitative problems that demanding the establishment of a stoichiometric ratios. This thesis defended considers the use of contextualized teaching strategies about some subject associated to the study of solution, can foster student learning through reflection and understanding of their own difficulties, besides to provide motivation and active participation. The target group is formed by students of the undergraduate distance education with major in chemistry education of the Universidade Federal do Rio Grande do Norte (UFRN), and they were chosen because this education system is expanding and its learning difficulties publications number is reduced as well. Thus, the first methodological stage was to identify the student’s main learning difficulties associated to the study of solutions through literature sources. Next, using an adapted script of the Plano Nacional do Livro Didático para o Ensino Médio (PNLEM, Textbook National Plan for High School), the approach of the content of solutions printed in educational materials used by the target group was analyzed. Afterward, a teaching unit was planned in the last methodological stage and, finally, a new teaching unite was given with a sequence of contextualized activities such as video presentation, dialogued lecture, questionnaires application, exercises, and an experiment, where the target group’s main difficulties related to learning of solution were identified. The participants of the teaching unit activities had some learning difficulties in understand concepts of compound, ion, charge, entropy and solubility, as well as to identify the ion charge, interpret statements, decode tables, use the chemical language, perform mathematical calculations and use concentration units, similar results raised in the literature sources. In order to work on these difficulties, these students were encouraged to expose, question and test their ideas about the phenomenon under study, allowing learn from their mistakes and reflect on the organization strategy of scientific explanatory models they use. Therefore, activities and information about learning difficulties presented in this thesis need to be critical reflection object, because it can help both students in the process of acquiring knowledge about the content of solutions and professors in the planning of their lessons.