Rezumat articol ediţie STUDIA UNIVERSITATIS BABEÅž-BOLYAI

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    STUDIA CHEMIA - Ediţia nr.1 din 2005  
         
  Articol:   KINETICS AND MECHANISM OF P-XYLENE OXIDATION BY CE(IV) IN AQUEOUS ACID MEDIUM. LFER AS AN ARGUMENT TO THE OXIDATION MECHANISM.

Autori:  GABRIELA-CRISTINA BUCÅžA, IOAN BÂLDEA. 		 
       
         
  Rezumat:  The oxidation of p–xylene in aqueous acidic media, (using perchloric acid), has been followed spectrophotometrically. The process proceeds in parallel with the water oxidation. This reaction follows a first-order kinetics and has been taken into consideration by subtracting its contribution to the consumption of Ce(IV) A first-order dependence on Ce(IV) concentration and a complex dependence on p-xylene and hydrogen ion concentrations have been established for the organic substrate oxidation. The effect of ionic strength on the reaction rate has been studied and activation parameters were calculated. The global reaction rate is consistent with a mechanism involving the rapid formation of a complex that suffers an intramolecular electron transfer. The linear free energy relationship of Hammett type has been obtained for the oxidation of various substituted toluenes with a negative and small reaction constant, which argues the suggested mechanism.  
         
     
         
         
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