Chemistry and environmental education: extraction of natural extracts from the brazilian semiarid

The insertion of everyday themes in Teaching Chemistry facilitates their contextualization and interdisciplinarity in the study of situations that involve themes related to agriculture and its potentialities. The productive activities in the chemical area are normally risky and potentially cause pollution, since it works with substances that often have toxic properties causing several environmental problems. The present work was developed in a Brazilian public school addressing the knowledge about the semiarid region of Paraiba and its richness in the aspect of chemistry and agriculture, through extraction of natural dyes and their importance for humanity. The extraction of dyes was carried out in an alcoholic medium using different species of flowers from the Brazilian semiarid region, being considered efficient, because when the extracts come into contact with the substances they offer greater distinction in the variation of colors. The synthesis of natural pigments from the semiarid resources of Paraiba was very enriching from the historical, socioeconomic and environmental point of view. During the experimental procedures developed at the school, a constant dialogue can be established between students and the school community, in order to demonstrate that these active teaching methodologies can help in the construction and reconstruction of scientific knowledge.