A kinetic study of electron transfer from L-Ascorbic acid to sodium perborate and potassium peroxy disulphate in aqueous acid and micellar media
✍ Scribed by K. C. Rajanna; K. Narsi Reddy; U. Umesh Kumar; P. K. Sai Prakash
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 796 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0538-8066
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✦ Synopsis
Kinetics of oxidation of L-ascorbic acid ( H 2 A J by sodium perborate (SPB) and peroxy disulphate ( P D S ) have been investigated in aqueous acid and rnicellar media. Reaction kinetics indicated first-order dependence on both loxidantl and [ H2AI. increase in ionic strength ( p J increased reaction rate only in H2S04 media. Rate of SPB oxidation of H2A has been accelerated by acidity in H N 0 3 and HCI media while a decreasing trend is observed in HCIO, and H2S04 media. The results are interpreted by various theories of acidity functions Reaction rate is enhanced by the addition of added I H 2 0 2 ] indicating a H 2 0 2 coordinated boron species to be active in the present system. In the absence of rnicelle, increase in lacid] altered the PDS-H2A reaction rate marginally (a very small positive effect with HC104 and negative effect with H2S0,). Most plausible mechanisms have been proposed on the basis of experimental results. Activation parameters evaluated for specific kinetic constants are in accord with outer sphere electron transfer mechanism. In SPB-H2A system, addition of