EXPERIMENTAÇÃO INVESTIGATIVA UTILIZANDO MATERIAIS ALTERNATIVOS: UMA PROPOSTA DIDÁTICA PARA O ENSINO E APRENDIZAGEM DE QUÍMICA

Abstract

Chemistry teaching has still been ruled by lessons that use the transmission-reception model which does not show any effective contributions to the individual’s improvement as a critic and active subject in the process of knowledge construction. Facing such situation, the objective of this research was to evaluate a didactic approach based on an investigative experimentation with alternative materials in the teaching-learning of inorganic functions contents (base/acid) in a state school of the public school system placed in the small city of Bananeiras-PB and had as participants twenty-eight(28) students from a second-year high school group. The present study was characterized by a qualified approach and carried out under a form of action research. The didactic proposal involved the following contents: base/acid concepts of Arrhenius, Bronsted-Lowry and Lewis, pH, heartburns, neutralization, base/acid strength and contemplated two expository and debate lesson taught with audiovisual and technological aids as well as the presentation of investigative experiments with alternative materials made by the students. As data collecting tools, it was used three questionnaires (pretest, post-test and evolution of the proposed methodology) and observations during the development of the approach. The analysis of the data for the objective questions was done from the tabulation in Excel and the subsequent elaboration of the graphs and for the subjective ones in a literal way. Based on the results obtained in the pre-test questionnaire, the low level of knowledge of the students was evident even though they had already studied the content of acids and bases in the 1st year and, revised at the beginning of the 2017 school year. The questioning of the study through the causes of heartburns e its possible ways of combating them provided moments of instructive discussions about the theme. The investigative experimentation used to verify the base/acid character of substances present in daily life using several natural indicators provided the students with concrete experiences regarding the characteristics of an acid or a base. The didactic proposal was classified as great for most pupils who took part of the research. Besides, all students stated that, using this proposal made it easier to relate the content of acids and bases with the substances present in their daily life and thus the proposal was able to promote learning in a more dynamic and motivating way. By analyzing the conceptual evolution, it can be noticed that the pupils expanded their level of knowledge regarding the inorganic functions content(base/acid) after the performance of the didactical proposal. This way, it is possible to conclude that the didactic proposal was able to set the student as an active subject in the process of knowledge construction.