Kinetics of oxidation of some reducing sugars by Mn(VII) and Cr(VI) in the presence of transition metal ions A comparative study.2013

Abstract

ABSTRACT The present paper describes the rate of oxidation of galactose, mannose, fructose, and maltose in an acidic solution of KMNO4. The rate of reaction was monitored spectrophotometrically under a wide range of experimental conditions. The effect OF CO (II), CR (III), and Fe (III) as homogenous catalysts was also studied. The reactions were also monitored at different temperatures. Activation parameters were evaluated. Pseudo first order rate constant increased with increasing increase in ionic and acidic strength of the reaction medium and depends on the concentration of Fe (III) and Cr (III) ions but not on the concentration of Co (II) ion. The lower value of EA RECORDED with Fe (III) or Cr (III) ions in the mixture suggests a positive rate enhancement with Cr (III) ion>Fe (in temperature, concentration of sugar, and oxidant. The rate of oxidation also increased with III)ion, the higher value of Ea with Co (II) suggest inhibition.On sugar reactivities,the result shows,galactose > manmose > fructose > maltose.