O pKa de indicadores ácido-base e os efeitos coloidais



Título del documento: O pKa de indicadores ácido-base e os efeitos coloidais
Revista: Quimica nova
Base de datos: PERIÓDICA
Número de sistema: 000313336
ISSN: 0100-4042
Autors: 1



Institucions: 1Universidade Estadual de Maringa, Departamento de Quimica, Maringa, Parana. Brasil
Any:
Període: Jun
Volum: 29
Número: 3
Paginació: 600-606
País: Brasil
Idioma: Portugués
Tipo de documento: Artículo
Enfoque: Aplicado, descriptivo
Resumen en inglés An experiment is proposed that can be included in undergraduate courses of chemistry. The subject is the acidity of organic compounds, which are employed as pH indicators, particularly in acid-base titrations. The indicators used are methyl orange, bromophenol blue and bromocresol green in aqueous medium. The influence of colloidal systems on the equilibrium is evaluated by the pKa. The colloids employed are surfactants like sodium dodecyl sulfate, cetyl-trimethylammonium bromide and a polymeric non-ionic F127 (pluronics). The effect of stabilization promoted by the system on the acidic or basic structureof the indicator establishes the action mechanism of the colloid on the pKa values
Disciplines Química
Paraules clau: Química orgánica,
Educación química,
pKa,
Experimentos de laboratorio,
Indicadores acido-base,
Sistemas coloidales
Keyword: Chemistry,
Organic chemistry,
Chemical education,
Laboratory experiments,
pKa,
Acid-base indicators,
Colloidal systems
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