Uso da Hibiscus rosa sinensis L. e da Hibiscus sabdariffa L. para o desenvolvimento de indicadores de pH de baixo custo em escolas técnicas estaduais
A cidbase indicators are substances that have the ability to change color in the presence of an acid or a base, since there is a change in the molecular level. Commercial pH indicators have a range of applications in the context of chemistry, however, mainly i...
| Autor principal: | Machado, Daniela |
|---|---|
| Formato: | Trabalho de Conclusão de Curso (Especialização) |
| Idioma: | Português |
| Publicado em: |
Universidade Tecnológica Federal do Paraná
2021
|
| Assuntos: | |
| Acesso em linha: |
http://repositorio.utfpr.edu.br/jspui/handle/1/26262 |
| Tags: |
Adicionar Tag
Sem tags, seja o primeiro a adicionar uma tag!
|
| Resumo: |
A cidbase indicators are substances that have the ability to change color in the presence of an acid or a base, since there is a change in the molecular level. Commercial pH indicators have a range of applications in the context of chemistry, however, mainly in public schools there is an absence of laboratories and / or supplies due to the high maintenance values they have. Aiming at greater accessibility to experimentation, lowcost experiments are an alternative to enhance students' learning. As an example of this type of teaching methodology, there is the use of indicators derived in a simple way using natural pigments extracted cold from an alcoholic solution and the species of flowers, H. rosasinensisand H. sabdariffa L, which provides a multitude of variation of media cores, when exposed to different pH. This production technique consists of exposing the flower petals to commercial ethyl alcohol at a concentration of 70 ⁰GL. The preparations of these indicators prove to be a good didactic resource in the teaching of chemistry, both in demonstrating the extraction technique and in teaching the concepts of pH. In addition, because they are natural acidbase indicators that are easy and accessible to obtain, and because of the use of reagents from renewable sources, the context of green chemistry and an interdisciplinarity with biology and the environment are evident. The natural indicators gave a pattern of nuclei close, and easy to differentiate, for the determination of the acidic (reddish), basic (green or yellow) or neutral (purplish) characteristic. There fore, the preparation of the indicators can be considered an alternative experimental methodology, with the use of viable resources in the teaching of chemistry, which can be used as lowcost experimentation in the classroom or as a remote activity in the pandemic scenario, since Handling is low risk and the production of toxic waste to the environment is nonexistent.. |
|---|