Determination of Acidity Constants by Gradient Flow-Injection Titration

• Manuel E. Minas da Piedade ^[1] ; António C. L. Conceição ^[2]
  1. [1] Universidade de Lisboa

     Universidade de Lisboa

     Socorro, Portugal

     
  2. [2] Centro de Química Estrutural, Instituto Superior Técnico, Portugal
• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 83, Nº 12, 2006, pág. 1853
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • The use of the gradient chamber flow-injection titration method (GCFIT) to determine acidity constants is illustrated through an experiment involving acetic and benzoic acids. The procedure relies on spectrophotometric detection and on the use of an acid–base indicator to obtain the relation between the pH and the absorbance of the solution throughout the titration. This constitutes a new approach to the determination of pKas by GCFIT. The experiment, which has been designed for an advanced undergraduate course in instrumental analysis, also serves to demonstrate the implementation of automated analytical procedures at the microscale level and a rigorous analysis of an acid–base titration.