Rafia Azmat
Department of Chemistry, Research Institute of Chemistry, Tinnah University for Women 5-C Nazimabad 74600 Karachi
Samreen Ahmed
Department of Chemistry, Research Institute of Chemistry, Tinnah University for Women 5-C Nazimabad 74600 Karachi
Sitwat Qureshi
Department of Physics and
3H.E.J. Research Institute of Chemistry
L.Tinnah University for Women 5-C Nazimabad 74600 Karachi
Faryal Vali Mohammed
Tinnah University for Women 5-C Nazimabad 74600 Karachi
Fahim Uddin
University of Karachi, Pakistan
ABSTRACT
Color fading was observed during the Methylene Green (MG) catalyzed oxidation of D-glucose (RH) in alkaline aqueous solution. The kinetics of aerobic oxidation of D-glucose with MG+ was investigated by change in optical density of the dye using spectrophotometer. The reaction was first order with respect to the concentration of substrate. The oxidation proceeds via complex formation between glucose and methylene green and the rate constant of the decay of the complex was determined. The oxidation-reduction reactions were observed at various experimental parameters like concentration of methylene green as well as glucose, ionic strength of the medium and temperature. Rate of reaction was found to be dependent upon concentration of glucose as a reducing agent and independent upon the concentration of dye. An increase in the temperature results in elevation of rate of reaction. Activation parameters such as Ea, ΔH*, ΔG* and ΔS* were determined by investigating rate of reaction at different temperature with different ionic strength. A mechanism consistent with above investigations has been proposed.
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How to cite this article
Rafia Azmat, Samreen Ahmed, Sitwat Qureshi, Faryal Vali Mohammed and Fahim Uddin, 2006. Aerobic Oxidation of D-Glucose by Methylene Green in Alkaline Aqueous Solution by Visible Spectrophotometry. Journal of Applied Sciences, 6: 2784-2788.
DOI: 10.3923/jas.2006.2784.2788
URL: https://scialert.net/abstract/?doi=jas.2006.2784.2788
DOI: 10.3923/jas.2006.2784.2788
URL: https://scialert.net/abstract/?doi=jas.2006.2784.2788
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