Abstract.
The
present paper deals with the kinetics and mechanism of Ru(III)
catalyzed oxidation of Ethylene glycol in an alkaline
solution of KBrO3 carried out in the temperature
range 30-450C.Mercuric acetate has been used as a
scavenger for Br- ion formed in the reaction mixture to prevent
parallel oxidation by bromine. First order kinetics with respect
to each [KBrO3] and [Ru(III) chloride] was observed
in the oxidation of Ethylene glycol. The reaction shows zeroth
order with respect to Ethylene glycol and [OH-] ,
whereas a negative effect is observed for [Cl-].
Negligible effect of mercuric acetate and ionic strength of the
medium has been observed .The reactive species of Ru(III) in
alkaline medium is [RuCl2(H2O)3(OH)].
A suitable mechanism in conformity with the kinetic observation
has been proposed.The various activation parameters such as
energy of activation (∆E*), the Arrhenius factor (A), entropy of
activation (∆S*) etc. were calculated from the rate measurements
at 30, 35, 40 and 450C.The rate has been derived on
the basis of obtained data.
KEYWORDS: Kinetics, mechanism, oxidation,
polyhydric alcohol, potassium bromate, Ru(III) catalyst.