Extratos etanólicos de frutas e flores foram caracterizados e avaliados como indicadores naturais de pH e para detecção do ponto final de titulações ácido-base. A análise qualitativa mostrou que tais extratos mudaram de cor em função do pH e que empregados em análise volumétrica essa mudança foi clara, rápida e satisfatória indicando o ponto final da titulação. Quantitativamente, aplicando-se análise estatística com 95% de confiabilidade, constatou-se que esses extratos podem substituir a fenolftaleína, que é o indicador comumente empregado nesta volumetria. Sugere-se que esses extratos sejam amplamente empregados em Química Analítica, especialmente na educação básica e em cursos de licenciatura em Química devido à acessibilidade de obtenção dos espécimes naturais empregados, bem como a facilidade de manuseio dos reagentes, baixos custo, toxidez reduzida e alto potencial para instigar o espírito científico dos alunos. Palavras Chave: indicadores; pH; ensino.Extracts in ethanol of fruits and flowers were characterized and evaluated as natural pH indicators and use to detect the end point of acid-base titrations. The qualitative analysis showed that the extracts changed color as a function of pH and when they applied to volumetric analysis, such change was clear, fast and satisfactory indicating the end point of the titration. Quantitatively, applying statistical analysis by 95% of confidence, it was verified that the extracts can replace the phenolphthalein, which is the commonly indicator used in this volumetry. It is suggested that the extracts be widely used in Analytical Chemistry, especially in basic education and courses for Teaching Certificates in Chemistry due to the accessibility of the natural specimens used as well as the easily handling reagent, low cost, low toxicity and high potential to instigate the students' scientific spirit.
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