Dinâmica oscilatória em sistemas contendo bromato e 1,4-ciclo-hexanodiona em meio ácido: I. Efeito da temperatura

• Main Author: Oliveira,Hyrla C. L.
• Publication Date: 2012
• Other Authors: Oliveira,Tatiane B., Varela,Hamilton
• Format: Article
• Language: por
• Source: Química Nova (Online)
• Download full: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422012000200022
• topic: oscillations; complex kinetics; 1,4-cyclohexanedione

We present in this work the influence of temperature on the dynamics of homogeneous chemical systems containing bromate and 1,4-cyclohexanedione (1,4-CHD) in acidic media. In particular, the following systems were studied: bromate/1,4-CHD/acid, bromate/1,4-CHD/ferroin/acid and bromate/1,4-CHD/trisbipyridine ruthenium/acid. Investigations were carried out by means of an electrochemical probe, at five temperatures between 5 and 45 °C. Activation energies (Ea) were estimated in different ways for the pre-oscillatory and oscillatory regimes. In any case, the Ea was found to depend on the catalyst, composition and initial concentrations. In addition, it was observed that ferroin and trisbipyridine ruthenium act as catalysts only during the transition between the induction period and oscillatory regime.