Antocianinas como indicadores ácido-base com potencial aplicação no espaço escolar

Abstract

Chemistry teaching becomes more attractive with the use of pedagogical resources such as experimentation and ICT. Verification of acidity or basicity behavior of aqueous solutions is usually performed with the extract of purple cabbage, which provides a good homemade acid-base indicator. However, the persistent use of this resource makes us think of proposing alternatives to this material, hence the idea of exploring other plant species that have potential as suppliers of acid-base indicators. Through bibliographical research, it is stated that species that contain anthocyanins in their structure have the characteristics of undergoing protonation and deprotonation reactions as a function of pH. One part of this work was to investigate, select, extract, test and analytically characterize acid-base indicators from plant species. Another part of the work consisted in preparing a digital didactic material that serves as a source of consultation for teachers interested in producing their own indicators. The last part consisted in validating the didactic material with a high school class. To do so, we made use of ICT as an aid in the realization of a workshop. The Kahoot! was used in order to review and / or fix the content covered.