Cementation kinetics of copper on a rotating zinc cylinder

1987 ◽  
Vol 52 (5) ◽  
pp. 1204-1210 ◽  
Author(s):  
Vladimír Glaser ◽  
Jan Vídenský ◽  
Miroslav Kužela
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Kinetic Equation ◽  
Rate Equation ◽  
Diffusion Region ◽  
First Order ◽  
Proportionality Constant ◽  
Zinc Surface ◽  
Reaction Proceeds ◽  
Kinetics Of

The authors followed the course of cementation of copper from sulphate solutions on a rotating zinc cylinder. Treatment of experimental data revealed that the coefficient of proportionality in the kinetic equation is not influenced by the Cu layer deposited on the zinc surface and is independent of the concentration of Cu(II) ions, but decreases with increasing concentration of ZnSO4 in solution. The cementation reaction proceeds in the diffusion region and is of the first order with respect to the concentration of Cu(II) ions; the proportionality constant in the rate equation corresponds to the mass transfer coefficient.

Kinetics of catalytic reduction of nitrogen oxide by carbon monoxide on CuO/Al2O3 catalyst

1983 ◽  
Vol 48 (11) ◽  
pp. 3202-3208 ◽  
Author(s):  
Zdeněk Musil ◽  
Vladimír Pour
Keyword(s):  
Carbon Monoxide ◽  
Nitrogen Oxide ◽  
Rate Equation ◽  
Catalytic Reduction ◽  
Zero Order ◽  
Spectroscopic Measurements ◽  
First Order ◽  
Ir Spectroscopic ◽  
Kinetics Of ◽  
Al2o3 Catalyst

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.

The kinetics of the decarboxylation of β-resorcylic acid in catechol

1976 ◽  
Vol 29 (2) ◽  
pp. 443 ◽  
Author(s):  
MA Haleem ◽  
MA Hakeem
Keyword(s):  
Rate Equation ◽  
Kinetic Data ◽  
Reaction Rate ◽  
Complex Mechanism ◽  
First Order ◽  
Absolute Reaction Rate ◽  
First Time ◽  
Kinetics Of ◽  
Absolute Reaction ◽  
Reaction Rate Equation

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.

Kinetics of Glyphosate Adsorption on Composite Resin from Aqueous Solution

2013 ◽  
Vol 803 ◽  
pp. 157-160
Author(s):  
Zhen Zhen Kong ◽  
Dong Mei Jia ◽  
Su Wen Cui
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Composite Resin ◽  
Order Equation ◽  
Second Order ◽  
First Order ◽  
Basic Resin ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Best Fit

The composite weakly basic resin (D301Fe) was prepared and examined using scanning electron microscopy and Fourier transform infrared spectroscopy. The adsorption kinetics of glyphosate from aqueous solution onto composite weakly basic resin (D301Fe) were investigated under different conditions. The experimental data was analyzed using various adsorption kinetic models like pseudo-first order, the pseudo-second order, the Elovich and the parabolic diffusion models to determine the best-fit equation for the adsorption of glyphosate onto D301Fe. The results show that the pseudo-second order equation fitted the experimental data well and its adsorption was chemisorption-controlled.

Pseudo-Homogenous Kinetics Model for the Synthesis of Dimethyl Carbonate from Urea and Methanol with Heterogeneous Catalyst

2011 ◽  
Vol 233-235 ◽  
pp. 481-486
Author(s):  
Wen Bo Zhao ◽  
Ning Zhao ◽  
Fu Kui Xiao ◽  
Wei Wei
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Dimethyl Carbonate ◽  
Side Reaction ◽  
Order Reaction ◽  
Zero Order ◽  
Kinetics Model ◽  
First Order ◽  
Zero Order Reaction ◽  
Kinetics Of

The synthesis of dimethyl carbonate (DMC) from urea and methanol includes two main reactions: one amino of urea is substituted by methoxy to produce the intermediate methyl carbamate (MC) which further converts to DMC via reaction with methanol again. In a stainless steel autoclave, the kinetics of these reactions was separately investigated without catalyst and with Zn-containing catalyst. Without catalyst, for the first reaction, the reaction kinetics can be described as first order with respect to the concentrations of methanol and methyl carbamate (MC), respectively. For the second reaction, the results exhibit characteristics of zero-order reaction. Over Zn-containing catalyst, the first reaction is neglected in the kinetics model since its rate is much faster than second reaction. After the optimization of reaction condition, the macro-kinetic parameters of the second reaction are obtained by fitting the experimental data to a pseudo-homogenous model, in which a side reaction of DMC synthesis is incorporated since it decreases the yield of DMC drastically at high temperature. The activation energy of the reaction from MC to DMC is 104 KJ/mol while that of the side reaction of DMC is 135 KJ/mol.

scholarly journals Modeling and experimental study of polyurethane foaming and gelling reactions

2018 ◽  
Author(s):  
◽  
Luay Jaf
Keyword(s):  
Experimental Data ◽  
Foam Height ◽  
Research Process ◽  
Catalytic Reactions ◽  
Polymerization Process ◽  
Gel Point ◽  
Reaction Proceeds ◽  
Polyurethane Foaming ◽  
Kinetics Of ◽  
Insight Into

Numerous reactions take place within a polyurethane polymerization process. Homogeneous and catalytic reactions occur at the same time and intermediate compounds are formed. As the reaction proceeds, long chains of polymer are formed which drastically affect the kinetics of the reaction. Temperature and viscosity profiles of the reacting mixture are two strong indicators of the extent of reaction and the way the reactions are carried out. Therefore, simulating polyurethane gel and foam systems helps interpret temperature and viscosity profiles and gain insight into the kinetics of the system. Using MATLAB program, a model was introduced which simultaneously solves over 80 ordinary differential equations and provide temperature and viscosity profiles as well as concentration profiles, degrees of polymerization, gel point and foam height for individual formulations. Experimental data were used to validate the code showing the model is fundamentally correct. Simulation results showed good fits to the experimental data providing reaction kinetics of the system. The model was modified to simulate reaction systems with minimal change in kinetic parameters. Finally, the simulation studies of this research provide fundamental insights into mechanism of homogenous and catalytic reactions. This research process places high demands on identifying and testing highly-impacting fundamental mechanism during polymerization that have not previously been identified.

Kinetics of the Heterogeneous Ozonation of Nitrated Phenols

1992 ◽  
Vol 26 (1-2) ◽  
pp. 169-180 ◽  
Author(s):  
J. P. Gould ◽  
G. V. Ulirsch
Keyword(s):  
Mass Transfer ◽  
Rate Constants ◽  
Chemical Structure ◽  
Process Analysis ◽  
Qsar Model ◽  
Zero Order ◽  
Transfer Coefficients ◽  
First Order ◽  
Kinetics Of ◽  
Phenolic Concentration

The kinetics of the heterogeneous ozonation of phenol and 27 nitrophenols representing a wide array of functional groups have been studied. In the systems examined, the process has been found to be zero order with respect to phenolic concentration which indicates mass transfer as the prime control on the process. Analysis of the first order rate constants has permitted computation of overall mass transfer coefficients for all compounds. The coefficients were sixty percent lower than the kLa values measured by others in water and showed very little variation regardless of chemical structure of the phenol. Efforts at development of a QSAR model for the kinetics were fruitless.

The trans-Effect in Octahedral Complexes. VI. Base Hydrolysis of trans-Hydroxybromo and trans-Hydroxychlorobis(ethylenediamine)-rhodium(III) Complexes

1975 ◽  
Vol 53 (12) ◽  
pp. 1842-1848 ◽  
Author(s):  
Anthony Poë ◽  
Carol Vuik
Keyword(s):  
Rate Equation ◽  
Base Hydrolysis ◽  
Small Contribution ◽  
Trans Effect ◽  
First Order ◽  
Order Rate ◽  
Pseudo First Order ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Order Rate Equation

The kinetics of base hydrolysis of the complexes trans-[Rh(en)2(OH)X]+ (X = Br or Cl) follow the pseudo first order rate equation kobs = k1 + k2[OH−]. The small contribution of the [OH−]-dependent term is due to lower values of ΔS2≠ − ΔS1≠ than are observed for the complexes cis-[Rh(en)2(OH)Cl]+ and [Rh(NH3)5X]2+ (X = Cl, Br, or I ). The values of ΔH1≠ are used to obtain new values of the intrinsickinetictrans-effect (i.k.t.e.) of hydroxide that agree with that determined from aquation of trans.-[Rh(en)2(OH)I]+ and place hydroxide in the i.k.t.e. series [Formula: see text] The new data also allow hydroxide to be placed in a thermodynamic trans-effect (t.t.e.) series I > OH > NH3 > Br > Cl > OH2, and the different position of hydroxide in the two series is discussed.

THE KINETICS OF THE FORMATION OF THE MONOSULPHATO COMPLEX OF IRON (III) IN AQUEOUS SOLUTION

1962 ◽  
Vol 40 (9) ◽  
pp. 1836-1845 ◽  
Author(s):  
G. G. Davis ◽  
W. MacF. Smith
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Ionic Strength ◽  
Continuous Flow ◽  
Hydrogen Ions ◽  
Kcal Mole ◽  
Forward Reaction ◽  
First Order ◽  
Kinetics Of Formation ◽  
Kinetics Of

The kinetics of formation of the monosulphato complex of iron (III) has been examined spectrophotometrically using a continuous-flow technique over the range of temperatures 15.6 to 34.5 °C in an aqueous medium of ionic strength 0.5 and a range of concentrations of hydrogen ions 0.05 to 0.30 M. The experimental data may be interpreted on the assumption that the significant reactions are a bimolecular association opposed by a first-order dissociation [Formula: see text] For the forward reaction ΔH≠ is 18.0 kcal mole−1 and ΔS≠ is 19.4 cal mole−1 deg−1.

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