Aplicação de um corante tiazolilazo como indicador ácido-base e determinação das suas constantes de ionização ácida Application of a thiazolylazo dye as an acid-base indicator and determination of its acid ionization constants
| Autor: | Regina Terumi Yamaki, Daniel Rodrigues Vieira, Cleber Galvão Novaes, Hygor Rodrigues de Oliveira, Valfredo Azevedo Lemos, Sandra Carvalho |
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| Jazyk: | English<br />Spanish; Castilian<br />Portuguese |
| Rok vydání: | 2009 |
| Předmět: | |
| Zdroj: | Química Nova, Vol 32, Iss 7, Pp 1943-1946 (2009) |
| Druh dokumentu: | article |
| ISSN: | 0100-4042 1678-7064 |
| DOI: | 10.1590/S0100-40422009000700042 |
| Popis: | The pKa values of the 6-[2´-(6´-methyl-benzothiazolylazo)]-1,2-dihydroxy-3,5-benzenedisulfonic acid (Me-BDBD) have been determined at 25 °C, in 0.10 mol L-1 NaCl medium by spectrophotometric method. The SQUAD computer program was used to process experimental data in pH range 1.78 - 11.54 and 290 - 720 nm. The pKa values obtained were 4.60 ± 0.04 and 9.48 ± 0.02. The Me-BDBD reagent was applied as indicator in titration of acid-base. The results were compared with phenolphthalein and bromocresol green indicators. Statistical t and F tests indicated that there were no statistically significant differences between the results for indicators with good agreement. |
| Databáze: | Directory of Open Access Journals |
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