O potencial da Arrabidaea chica (pariri) como indicador naturalácido-base: uma proposta para o ensino de ciências.

Abstract

Experimentation is a good teaching strategy that contributes to teaching and learning in natural sciences. Among the various science subjects that can be worked on through experimentation, it is worth mentioning the acidity and basicity of substances, as it is a topic that is present in the student's daily life. Under such a scenario, the acid and base themes can be studied through natural indicators, these are natural extracts that have anthocyanins as a base, and they are pigments of the flavonoid class that can be used to determine the pH of various samples. In this sense, Arrabidaea chica popularly known as Pariri is one of several plants that contain anthocyanin. Thus, the present study aimed to identify the acid-base indicator properties of the plant extract of the A. chica species, considering its use as a natural indicator for testing the pH of drinking water and rainwater applied in science teaching. For this, the research was developed in 3 stages: preparation of the alcoholic extract of A. chica, application of the alcoholic extract of A. chica as a pH indicator with students of the 9th grade of elementary school at the Public school Maria Conceição Malheiro in Irituia-PA and the composition of the educational product. The final product of the research was a booklet that addressed the pH of drinking water and how to create a natural pH indicator from the alcoholic extract of A. chica. It is concluded that the A. chica extract can be used as a pH indicator, showing a very satisfactory acid-base color change when applied to the tested samples. It was also evident that there was a great involvement of students and teachers with the proposed experience and how the approximation of scientific knowledge with students' daily lives can favor the teaching-learning process. The final product of the research, when applied to the teachers, had a satisfactory response in the School that was the object of this study and could help other teachers from other places.