CATALYTIC ACTIVATION OF HYDROGEN IN AQUEOUS SOLUTION BY THE CHLOROPALLADATE(II) ION

1959 ◽  
Vol 37 (9) ◽  
pp. 1446-1450 ◽  
Author(s):  
J. Halpern ◽  
J. F. Harrod ◽  
P. E. Potter
Keyword(s):  
Aqueous Solution ◽  
Ferric Chloride ◽  
Molecular Hydrogen ◽  
Homogeneous Catalyst ◽  
Rate Law ◽  
Catalytic Activation ◽  
Kinetics Of ◽  
Mechanism Of The Reaction

The kinetics of the reduction of ferric chloride by molecular hydrogen in aqueous solution, in the presence of chloropalladate(II), were examined. The latter acts as a homogeneous catalyst for the reaction. The rate-law was found to be,[Formula: see text]where[Formula: see text]The mechanism of the reaction is discussed.

Ferricyanide Oxidation of Butanol Homogeneously Catalysed by Chlororuthenium Complexes

1979 ◽  
Vol 32 (9) ◽  
pp. 1905 ◽  
Author(s):  
AF Godfrey ◽  
JK Beattie
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Linear Dependence ◽  
Rate Constants ◽  
Homogeneous Catalyst ◽  
Basic Solution ◽  
Rate Law ◽  
Kinetics Of ◽  
Solution Estimates ◽  
Butanol Concentration

The oxidation of butan-1-ol by ferricyanide ion in alkaline aqueous solution is catalysed by solutions of ruthenium trichloride hydrate. The kinetics of the reaction has been reinvestigated and the data are consistent with the rate law -d[FeIII]/dt = [Ru](2k1k2 [BuOH] [FeIII])/(2k1 [BuOH]+k2 [FeIII]) This rate law is interpreted by a mechanism involving oxidation of butanol by the catalyst (k1) followed by reoxidation of the catalyst by ferricyanide (k2). The non-linear dependence of the rate on the butanol concentration is ascribed to the rate-determining, butanol-independent reoxidation of the catalyst, rather than to the saturation of complex formation between butanol and the catalyst as previously claimed. Absolute values of the rate constants could not be determined, because some of the ruthenium precipitates from basic solution. With K3RuCl6 as the source of a homogeneous catalyst solution, estimates were obtained at 30�0�C of k1 = 191. mol-1 s-1 and k2 = 1�4 × 103 l. mol-1 s-1.

CATALYTIC ACTIVATION OF MOLECULAR HYDROGEN BY RUTHENIUM (III) CHLORIDE COMPLEXES

1961 ◽  
Vol 39 (6) ◽  
pp. 1372-1376 ◽  
Author(s):  
J. F. Harrod ◽  
Stefania Ciccone ◽  
J. Halpern
Keyword(s):  
Molecular Hydrogen ◽  
Present System ◽  
Chloride Complexes ◽  
Rate Law ◽  
Catalytic Activation ◽  
Catalyzed Reactions ◽  
Kinetics Of ◽  
Hcl Solution

Ruthenium(III) chloride, in aqueous HCl solution, was found to activate H2 homogeneously and to catalyze the reduction by H2 of Ru(IV)and Fe(III). The kinetics of these reactions were examined and, in each case, the rate law was found to be −d[H2]/dt = k1[H2][RuIII] where k1 = 4.0 × 1014 exp [−23,800/RT] M−1 sec−1. The mechanisms of these reactions are discussed and compared to those of other homogeneously catalyzed reactions of hydrogen. A special feature of the present system is the resistance of the catalytic species itself (i.e. RuIII) to reduction by H2.

Kinetics and mechanism of the reaction of iron(III) with 6-methyl-2,4-heptanedione and 3,5-heptanedione

1990 ◽  
Vol 55 (8) ◽  
pp. 1984-1990 ◽  
Author(s):  
José M. Hernando ◽  
Olimpio Montero ◽  
Carlos Blanco
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Activation Parameters ◽  
Enol Form ◽  
Kinetics And Mechanism ◽  
Kinetic Constants ◽  
Steric Factors ◽  
Kinetics Of ◽  
Mechanism Of The Reaction

The kinetics of the reactions of iron(III) with 6-methyl-2,4-heptanedione and 3,5-heptanedione to form the corresponding monocomplexes have been studied spectrophotometrically in the range 5 °C to 16 °C at I 25 mol l-1 in aqueous solution. In the proposed mechanism for the two complexes, the enol form reacts with the metal ion by parallel acid-independent and inverse-acid paths. The kinetic constants for both pathways have been calculated at five temperatures. Activation parameters have also been calculated. The results are consistent with an associative activation for Fe(H2O)63+ and dissociative activation for Fe(H2O)5(OH)2+. The differences in the results for the complexes of heptanediones studied are interpreted in terms of steric factors.

KINETICS OF THE CUPRIC ACETATE CATALYZED HYDROGENATION OF DICHROMATE IN AQUEOUS SOLUTION

1955 ◽  
Vol 33 (2) ◽  
pp. 356-364 ◽  
Author(s):  
E. Peters ◽  
J. Halpern
Keyword(s):  
Activation Energy ◽  
Aqueous Solution ◽  
Partial Pressure ◽  
Kinetic Study ◽  
Reaction Rates ◽  
Homogeneous Catalyst ◽  
Cupric Acetate ◽  
Partial Pressures ◽  
Kinetics Of

In aqueous solution, cupric acetate was found to act as a homogeneous catalyst for the reduction of dichromate by hydrogen, i.e.[Formula: see text] The paper describes a kinetic study of this reaction. Rates were determined at temperatures between 80° and 140 °C. and hydrogen partial pressures up to 27 atmospheres. The rate is independent of the dichromate concentration but varies directly with the partial pressure of hydrogen and is nearly proportional to the concentration of cupric acetate. The activation energy is 24,600 calories per mole. Cupric acetate, apparently acting as a true catalyst, activates the hydrogen through formation of a complex with it. An extension of the mechanism proposed earlier for the reaction of cupric acetate itself with hydrogen also accounts for the kinetics of the dichromate reaction.

scholarly journals Kinetics of gibbsite leaching in sodium hydroxide aqueous solution

2002 ◽  
Vol 56 (9) ◽  
pp. 381-385
Author(s):  
Ljubica Pavlovic ◽  
Zagorka Acimovic-Pavlovic ◽  
Ljubisa Andric ◽  
Aurel Prstic
Keyword(s):  
Activation Energy ◽  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Sodium Hydroxide ◽  
Kinetic Parameters ◽  
Rate Constant ◽  
Reaction Rate ◽  
Reaction Rate Constant ◽  
Kinetics Of ◽  
Mechanism Of The Reaction

In order to study the kinetics and mechanism of the reaction, laboratory leaching was carried out with industrially produced gibbsite ?-Al(OH)3 in aqueous solutions containing an excess of sodium hydroxide. The results obtained reaction temperature, duration and base concentration varied. The basic kinetic parameters were determined from: the reaction rate constant k=8.72?107 exp (-74990/RT) and the process activation energy in the range Ea=72.5-96.81 kJ/mol.

KINETICS OF THE HOMOGENEOUS REACTION BETWEEN CUPRIC ACETATE AND MOLECULAR HYDROGEN IN AQUEOUS SOLUTION

1954 ◽  
Vol 32 (10) ◽  
pp. 969-978 ◽  
Author(s):  
R. G. Dakers ◽  
J. Halpern
Keyword(s):  
Aqueous Solution ◽  
Cuprous Oxide ◽  
Molecular Hydrogen ◽  
Sodium Acetate ◽  
Reaction Rates ◽  
Reaction Vessel ◽  
Homogeneous Reaction ◽  
Cupric Acetate ◽  
Partial Pressures ◽  
Kinetics Of

Cupric acetate was found to react homogeneously with molecular hydrogen in aqueous solution according to the following equation:[Formula: see text]The paper describes a kinetic study of this reaction. Rates were determined at temperatures between 80 and 140 °C and hydrogen partial pressures between 6.8 and 34.0 atm. The reaction was found to be of second order, the rate being proportional to the concentrations of cupric acetate and molecular hydrogen. It was established that the rate was independent of the surface of the reaction vessel, the cuprous oxide product and of the concentrations of sodium acetate and acetic acid in the solution. The reaction has an activation energy of 24200 cal. per mole. The kinetic results are discussed and a mechanism is proposed. This appears to be one of the few known homogeneous reactions of molecular hydrogen in solution.

scholarly journals Kinetics of the Reaction between Ni(tetren)2+and Bipyridine

2012 ◽  
Vol 1 (2) ◽  
pp. 39-45
Author(s):  
Lawrence Hugh Kolopajlo ◽  
Nekuma Korey Hollis ◽  
Ian Pendelton
Keyword(s):  
Aqueous Solution ◽  
Rate Constants ◽  
Substitution Reaction ◽  
Ternary Complex ◽  
Ligand Substitution ◽  
Hydrogen Ion ◽  
Rate Law ◽  
Kinetics Of ◽  
Ligand Substitution Reaction

We report a rate law, rate constants and a mechanism for the ligand substitution reaction between Ni(tetren)2+ and 2, 2'-bipyridine in aqueous solution at 25.0 0C. The rate law is: R = k [Ni(tetren2+)] [bipy]. The data supports a mechanism involving a hydrogen ion assisted pathway in which a ternary complex is not formed.

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