Produtos de limpezas saneantes domissanitários no ensino de Química: uma abordagem contextualizada para aprendizagem de substâncias e reações químicas.

Abstract

The teaching of Chemistry is still being based on activities that aim mostly at memorizing information, formulas and knowledge, which may limit students' learning and, therefore, contribute to their demotivation in relation to learning and studying Chemistry. That being said, it seems necessary to use different methodological approaches, which have been shown to be viable alternatives to traditional teaching. Among them, contextualization has been highlighted for enabling students to construct and reconstruct significant knowledge of chemicals and allow them to interpret the physical world based on science. Based on that premise, the general objective of this research is to identify household cleaning products based on a contextualized approach to learning substances and chemical reactions. Regarding the approach of this research, it is classified as qualitative; as for the objective, it is reached through an explorative manner; and in relation to the adopted procedures, this research is defined as a field study. The research was carried out in a State school, located in the Mesoregion of Agreste Paraibano and in the Microregion of Curimataú Ocidental, in the city of Arara, and the participants were students from two senior high school classes, identified by the pseudonyms D1 through D46. With due authorization from the school’s manager, teachers and students, the research was carried out with the help of a Didactic Sequence, constituted of thirteen pedagogical steps, whose specific methodology was based on contextualization. The data were constructed with the students' responses during the assessment of prior knowledge; analysis of household cleaning products’ labels in accordance with ANVISA’s (The Brazilian Health Regulatory Agency) parameters; their association with chemical reactions; development of a conceptual map; and the production of an argumentative written report. The analysis of the obtained data was carried out based Discourse Analysis theories. The results shown a significant change in students' knowledge in regards to substances (when identifying their formation, and also their pure and compound states) and chemical reactions (when identifying reaction types and characteristics). On their reports, the students presented reasonable arguments and made more critical readings of reality in regards to the damage that these products cause to the environment. Therefore, we concluded that the use of contextualization in Chemistry teaching is capable of contributing to a meaningful learning of subjects, probably because it promotes the active participation of students and brings their experiences closer to scientific knowledge and, consequently, making the understanding and learning of chemistry subjects that are being studied more effective.