Spectroscopic analysis of proton exchange during the photocatalytic decomposition of aqueous acetic acid: an isotopic study on the product distribution and reaction rate

2018 ◽  
Vol 8 (22) ◽  
pp. 5886-5899 ◽  
Author(s):  
Saher Hamid ◽  
Ralf Dillert ◽  
Jenny Schneider ◽  
Detlef W. Bahnemann
Keyword(s):  
Carbon Dioxide ◽  
Acetic Acid ◽  
Molecular Hydrogen ◽  
Reaction Rate ◽  
Spectroscopic Analysis ◽  
Product Distribution ◽  
Proton Exchange ◽  
Photocatalytic Decomposition ◽  
Aqueous Acetic Acid ◽  
Isotopic Study

The photocatalytic decomposition of aqueous acetic acid into molecular hydrogen, carbon dioxide, and hydrocarbons employing platinized titania (Pt/TiO2) as a photocatalyst has been studied.

scholarly journals Perborate Oxidation of Substituted 5-Oxoacids in Aqueous Acetic Acid Medium: A Kinetic and Mechanistic Study

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
S. Shree Devi ◽  
B. Muthukumaran ◽  
P. Krishnamoorthy
Keyword(s):  
Acetic Acid ◽  
Acid Medium ◽  
Reaction Rate ◽  
Reaction Medium ◽  
Activation Parameters ◽  
Reaction Rates ◽  
Mechanistic Study ◽  
Aqueous Acetic Acid ◽  
Sodium Perborate ◽  
Acetic Acid Medium

Kinetics and mechanism of oxidation of substituted 5-oxoacids by sodium perborate in aqueous acetic acid medium have been studied. The reaction exhibits first order both in [perborate] and [5-oxoacid] and second order in [H+]. Variation in ionic strength has no effect on the reaction rate, while the reaction rates are enhanced on lowering the dielectric constant of the reaction medium. Electron releasing substituents in the aromatic ring accelerate the reaction rate and electron withdrawing substituents retard the reaction. The order of reactivity among the studied 5-oxoacids is p-methoxy ≫ p-methyl > p-phenyl > –H > p-chloro > p-bromo > m-nitro. The oxidation is faster than H2O2 oxidation. The formation of H2BO3+ is the reactive species of perborate in the acid medium. Activation parameters have been evaluated using Arrhenius and Eyring’s plots. A mechanism consistent with the observed kinetic data has been proposed and discussed. Based on the mechanism a suitable rate law is derived.

Structure of chitin in the cell walls of newly formed and mature conidia of Fusarium sulphureum

1982 ◽  
Vol 28 (5) ◽  
pp. 531-535 ◽  
Author(s):  
E. F. Schneider ◽  
W. L. Seaman
Keyword(s):  
Cell Wall ◽  
Acetic Acid ◽  
Cell Walls ◽  
Molecular Hydrogen ◽  
Spectroscopic Analysis ◽  
Conidiogenous Cell ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Fusarium Sulphureum

Samples of 7-day-old septate conidia (mature conidia) and newly released aseptate ones (immature conidia) of Fusarium sulphureum were hydrolyzed successively in KOH, acetic acid – H2O2, and H2SO4. The cell wall residue of the mature conidia remained intact throughout the hydrolysis but that of immature conidia dissolved in the H2SO4. Thus, the immature conidial cell wall is substantially different from that of mature conidial cells or growing hyphae and the cell wall undergoes a structural transformation following conidium release from the conidiogenous cell. X-ray diffraction analyses of the wall residues following KOH and acetic acid – H2O2 hydrolysis showed that the mature conidial wall residue had a crystalline chitin component, while the residue of the immature conidial wall was more amorphous and had smaller crystals. An X-ray diffraction pattern of the dissolved immature conidial wall that was recovered from the H2SO4 hydrolysate showed that it contained crystalline chitin.Infrared spectroscopic analysis of the mature conidial cell wall residue showed absorption bands due to inter- and intra-molecular hydrogen bonding and for hydrogen stretching associated with crystalline chitin. Such bands were lacking in the immature cell wall analogue.

scholarly journals Kinetics of Oxidation of Benzoin by N. Bromosuccinimide

2005 ◽  
Vol 4 (1) ◽  
pp. 55-61
Author(s):  
R. Sridharan ◽  
N. Mathiyalagan
Keyword(s):  
Dielectric Constant ◽  
Acetic Acid ◽  
Reaction Rate ◽  
Activation Parameters ◽  
Aqueous Acetic Acid ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
First Order Kinetics ◽  
Retarding Effect ◽  
Kinetics Of

Kinetics of Oxidation of Benzoin by N. Bromosuccinimide[NBS] 80% aqueous acetic acid has been investigated. The reaction follows first-order kinetics with respect to both[NBS] and [benzoin]. The effect of varying ionic strength and dielectric constant indicate the reaction is dipole-dipole type. Addition of succinimide(>NH), has a retarding effect on the rate of oxidation. The product of oxidation is benzil. By studying the effect of temparature on the reaction rate, the Arrhenius and the activation parameters have been calculated. A suitable mechanism has been proposed and a rate low explaining the experiment results is derived.

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