Abstract

SILVA, Dirlei Badotti da et al. Set of proposals using natural products to introduce the acid-base theme (part II): extraction and storage. Educ. quím [online]. 2018, vol.29, n.2, pp.3-16. ISSN 0187-893X.  https://doi.org/10.22201/fq.18708404e.2018.1.63702.

Compounding the set proposals using alternative pH indicators from vegetables and leaves, in Part I purple cabbage, beet, purple onion and eggplant were tested. In this manuscript (Part II) was investigated, from products of students daily life, the behavior of extracts from saffron (Curcuma sp.), coleus-de-Java (Solenostemon sp.), black beans (Phaseolus sp.) and purple trapoeraba (Tradescantia sp.). The extracts were obtained from the aqueous medium extraction. The time storage of each extract and the coloration observed was monitored. These allow investigating the pH of the daily products using extracts from natural products.

Keywords : Chemistry teaching; pH Indicator; Green Chemistry; Natural Products Extraction.