Rate of reaction of dithionite ion with oxygen in aqueous solution

1964 ◽  
Vol 19 (3) ◽  
pp. 522-525 ◽  
Author(s):  
J. A. Morello ◽  
Margot R. Craw ◽  
H. P. Constantine ◽  
R. E. Forster

The rate of removal of oxygen from aqueous solution by sodium dithionite in 0.1 m sodium hydroxide was studied in a rapid-reaction apparatus using a membrane-covered polarographic cell to determine Po2 in the flowing liquid. The measurements were made at 37 C, so that the data would be applicable in studies of the kinetics of oxyhemoglobin in blood. The initial concentrations in the mixed reacting solution were between 8 x 10-5 m and 47.5 x 10-5 m for dithionite, and either 10 x 10-5 m or 47.8 x 10-5 m for O2. The reaction over the first 40 msec was found to be first order with respect to dithionite and zero order with respect to molecular oxygen. The initial rate constant was 42.5 ± sd 3.6 sec-1. oxygen reduction by dithionite; hemoglobin; deoxygenation rate; dithionite-oxygen reaction rate Submitted on June 17, 1963

1966 ◽  
Vol 19 (8) ◽  
pp. 1365 ◽  
Author(s):  
RH Smith ◽  
IR Wilson

Initial rates of reaction for the above oxidation have been measured by a stopped-flow conductance method. Between pH 2 and 3.6, the initial rate of reaction, R, is given by the expression R{[HSO5-]+[SCN-]} = {kb+kc[H+]}[HSO5-]0[SCN-]20+ka[H+]-1[HSO5]20[SCN-]0 As pH increases, there is a transition to a pH-independent rate, first order in each thiocyanate and peroxomonosulphate concentrations.


1978 ◽  
Vol 33 (6) ◽  
pp. 657-659 ◽  
Author(s):  
M. P. Singh ◽  
A. K. Singh ◽  
Mandhir Kumar

Abstract The present paper deals with the kinetics of oxidation of D-galactose by Nessler's reagent in alkaline medium. The reaction is zero order with respect to Hg(II) and first order with respect to reducing sugar. The direct proportionality of the reaction rate at low hydroxide ion concentrations shows retarding trend at higher concentrations. The reaction rate is inversely proportional to iodide ion concentration. A mechanism has been proposed taking HgI3- as the reacting species


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Iqbal Ahmad ◽  
Kefi Iqbal ◽  
Muhammad Ali Sheraz ◽  
Sofia Ahmed ◽  
Tania Mirza ◽  
...  

The polymerization of 1–3 M 2-hydroxyethyl methacrylate (HEMA) initiated by riboflavin/triethanolamine system has been studied in the pH range 6.0–9.0. An approximate measure of the kinetics of the reaction during the initial stages (~5% HEMA conversion) has been made to avoid the effect of any variations in the volume of the medium. The concentration of HEMA in polymerized solutions has been determined by a UV spectrophotometric method at 208 nm with a precision of ±3%. The initial rate of polymerization of HEMA follows apparent first-order kinetics and the rates increase with pH. This may be due to the presence of a labile proton on the hydroxyl group of HEMA. The second-order rate constants for the interaction of triethanolamine and HEMA lie in the range of 2.36 to  M−1 s−1 at pH 6.0–9.0 suggesting an increased activity with pH. An increase in the viscosity of HEMA solutions from 1 M to 3 M leads to a decrease in the rate of polymerization probably as a result of the decrease in the reactivity of the flavin triplet state. The effect of pH and viscosity of the medium on the rate of reaction has been evaluated.


1992 ◽  
Vol 57 (12) ◽  
pp. 2583-2592 ◽  
Author(s):  
Jana Krupičková ◽  
Jaroslav Včelák ◽  
Jiří Hetflejš

Kinetics of the title reactions has been studied, using nickel(II) 2,4-pentanedionate/triethylaluminium system as a model catalyst. Initial rate measurements showed that in both cases the hydrogenation is first order in hydrogen, zero order in the octadecanoate and a fractional order (close to one) in the catalyst. Both hydrogenations have similar activation energies (30.2 ± 2.3 kJ mol-1 and 28.9 ± 2.6 kJ mol-1 for the (Z)- and (E)-9-octadecenoate, respectively). Based on these data and the results of competition experiments, two models have been proposed to describe isomerization of the octadecenoates (either direct or via an intermediate).


Author(s):  
L. Pushpalatha

The oxidation of malic acid by N-bromonicotinamide in the presence of micellar system is studied. First order kinetics with respect to NBN is observed. The kinetics results indicate that the first order kinetics in hydroxy acid at lower concentrations tends towards a zero order at its higher concentrations. Inverse fractional order in [H+] and [nicotinamide] are noted throughout its tenfold variation. Variation of [Hg (OAc)2] and ionic strength of the medium do not bring about any significant change in the rate of reaction. Rate of the reaction increases with a decrease in the percentage of acetic acid. Decrease in the rate constant was observed with the increase in [SDS]. The values of rate constants observed at four different temperatures were utilized to calculate the activation parameters. A suitable mechanism consistent with the experimental findings has been proposed.


Author(s):  
Ibrahim A. Salem ◽  
M. El-Maazawi

The kinetics of the oxidation of quinaldine red, a cationic dye, using hydrogen peroxide has been studied in aqueous solution. The rate of reaction was found to be first order in [quinaldine red] whereas in hydrogen peroxide it varies from one to zero with increasing [H


2013 ◽  
Vol 634-638 ◽  
pp. 546-550
Author(s):  
Xin Jie Li ◽  
Dan Dan Jiang ◽  
Yue Jun Zhang

Based on the mechanism of ClO3-/Cl-reaction system, the kinetics for reaction of sodium chlorate and hydrochloric acid to generate ClO2was studied. The rate equation of this reaction system was deduced and simplified as a formula with mixed-order (combination of first-order and second-order) towards ClO3-. This rate formula indicates that the initial rate of the reaction is the first-order with respect to ClO3-, and the reaction rate is the second-order with respect to ClO3-when [ClO3-] becomes close to zero. The rate constants of the first-order were determined as 0.0168s-1(30°C), 0.0221s-1(40°C), and 0.0279s-1(50°C), respectively, and that of the second-order were obtained for 0.0019L·mol-1·s-1(30°C), 0.0028L·mol-1·s-1(40°C), and 0.0060L·mol-1·s-1(50°C), respectively. The results of statistic test prove that the rate formula obtained in this work is credible.


1987 ◽  
Vol 52 (1) ◽  
pp. 88-92 ◽  
Author(s):  
Milica Miadoková ◽  
Magdalena Plchová ◽  
Ivan Halaša

The effect of the concentration of OH- ions, oxygen pressure, and temperature on the rate of reaction of aluminium in aqueous solution of sodium hydroxide was studied for surface planes corresponding to the (100), (110), and (111) crystallographic planes. Kinetic anisotropy was observed: the reaction rate increased and the apparent activation energy decreased in order (100)-(110)-(111). The kinetic parameters were related to some physical characteristics of the surface.


1983 ◽  
Vol 48 (11) ◽  
pp. 3202-3208 ◽  
Author(s):  
Zdeněk Musil ◽  
Vladimír Pour

The kinetics of the reduction of nitrogen oxide by carbon monoxide on CuO/Al2O3 catalyst (8.36 mass % CuO) were determined at temperatures between 413 and 473 K. The reaction was found to be first order in NO and zero order in CO. The observed kinetics are consistent with a rate equation derived from a mechanism proposed on the basis of IR spectroscopic measurements.


1976 ◽  
Vol 29 (2) ◽  
pp. 443 ◽  
Author(s):  
MA Haleem ◽  
MA Hakeem

Kinetic data are reported for the decarboxylation of β-resorcylic acid in resorcinol and catechol for the first time. The reaction is first order. The observation supports the view that the decomposition proceeds through an intermediate complex mechanism. The parameters of the absolute reaction rate equation are calculated.


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