SciELO - Scientific Electronic Library Online

 
vol.31 issue2Electrometric studies on formation of cerium vanadates as a function of pHLead ions determination in ethanol fuel by differential pulse anodic stripping voltammetry using a carbon paste electrode modified with ion-exchange resin Amberlite IR120 author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Eclética Química

Print version ISSN 0100-4670

Abstract

FERNANDES, N. S.; ARAUJO, S. A.  and  IONASHIRO, M.. Kinetic evaluation of the dehydration of Yb(III) Lu(III) and Y(III) 4-chlorobenzylidenepyruvate by thermogravimetry (TG). Eclet. Quím. [online]. 2006, vol.31, n.2, pp. 39-43. ISSN 0100-4670.  http://dx.doi.org/10.1590/S0100-46702006000200006.

The dehydration kinetic of Yb, Lu and Y 4-chlorobenzylidenepyruvate was studied by using thermogravimetry and the kinetics parameters obtained by Flynn and Wall method suggest that the dehydration step follows a first order mechanism. The activation energies calculated were 103.6, 96.6 and 97.2 kJ/mol and the lifetime considering the temperature of 31 and 101 º C for the dehydration of these compounds were 23, 26, 31 minutes and 0.6, 1.3 and 1.4 seconds, respectively. The results have similar values and suggest that the water is attached in the same way.

Keywords : kinetic; thermogravimetry; lanthanides; thermal decomposition.

        · abstract in Portuguese     · text in English     · pdf in English