Kinetics of electron transfer reaction between manganate and permanganate ions. Calculation of rate constant and activation energy

1977 ◽  
Vol 73 (0) ◽  
pp. 648 ◽  
Author(s):  
Sergei P. Dolin ◽  
Revaz R. Dogonadze ◽  
Ernst D. German
Keyword(s):  
Activation Energy ◽  
Electron Transfer ◽  
Rate Constant ◽  
Transfer Reaction ◽  
Electron Transfer Reaction ◽  
Kinetics Of

scholarly journals The Kinetics of Electron Transfer Reaction of Methylene Blue and Titanium Trichloride in different Solvents

2017 ◽  
Vol 6 (2) ◽  
pp. 940-957 ◽  
Author(s):  
Rehana Saeed Saeed
Keyword(s):  
Activation Energy ◽  
Methylene Blue ◽  
Electron Transfer ◽  
Transfer Reaction ◽  
Reaction Pathway ◽  
Reaction Medium ◽  
Electron Transfer Reaction ◽  
Rate Of Reaction ◽  
Titanium Trichloride ◽  
Kinetics Of

The kinetics of the electron transfer reaction of methylene blue and titanium trichloride was studied in water and aqueousalcoholic solvents at various temperatures by spectrophotometry. The rate of reaction was observed by taking change inabsorbance as a function of time at λmax 660 nm. The reaction is pseudo-first order, dependent on concentration of titaniumtrichloride at fixed concentration of methylene blue.The effect of solvent was studied in the pH/Ho range from 4 to 7. It was observed that the rate of reaction increased withincrease in polarity of the reaction medium. The rate of reaction was high in acidic condition and decreased with furtherincrease in hydrogen ions activity. The increase in temperature increased the rate of electron transfer reaction of methyleneblue and titanium trichloride. Activation energy (Ea) was calculated by Arrhenius relation. The absence of any reactionintermediate was confirmed by spectroscopic and kinetic investigations. A plausible mechanism for the reaction in line withouter-sphere reaction pathway has been proposed. Thermodynamic parameters such as activation energy (Ea), enthalpychange (∆H), free energy change (∆G) and entropy change (∆S) were also evaluated.

FT-EPR Study of Spin-correlated Radical Pairs Formed by Electron Transfer Quenching of Porphyrin Triplets in Micellar Solution

1998 ◽  
Vol 02 (04) ◽  
pp. 353-361 ◽  
Author(s):  
VOLKER WEIS ◽  
HANS VAN WILLIGEN
Keyword(s):  
Electron Transfer ◽  
Statistical Model ◽  
Rate Constant ◽  
Micellar Solution ◽  
Transfer Reaction ◽  
Electron Transfer Reaction ◽  
Cetyltrimethylammonium Chloride ◽  
Radical Pairs ◽  
Homogeneous Solutions ◽  
Kinetics Of

The spin-correlated radical pairs (SCRPs) formed by photoinduced electron transfer from zinc tetrakis(4-sulfonatophenyl)porphyrin ( ZnTPPS ) to quinones in micelles of the cationic surfactant cetyltrimethylammonium chloride ( CTAC ) were studied by means of Fourier transform EPR (FT-EPR). It is shown that variation of the power of the microwave pulse allows the separation of EPR signals arising from SCRPs and free radicals. The measured kinetics of radical formation can be accounted for in terms of a statistical model taking into account the non-uniform distribution of the solutes over the micelles. The rate constant of electron transfer quenching (kq) of the ZnTPPS triplet state by duroquinone (DQ) is found to be 1.05 × 106 s−1. The FT-EPR measurements gave information also on the kinetics of the homogeneous electron transfer reaction DQ − + DQ → DQ + DQ − in CTAC solution in which the DQ − anion radicals were generated by light-induced electron transfer from ZnTPPS . It is found that the dependence of the rate of this reaction on quinone concentration deviates from the linear relationship found in homogeneous solutions. A statistical model is proposed to account for the data. Based on this model, the rate constant of the self-exchange reaction (k ex ) is 4.1 × 106 s−1. From results obtained with duroquinone and benzoquinone as acceptors, it is concluded that ZnTPPS is located at the micelle/water interface.

Kinetics of Electron Transfer Reaction between Co(II) and Chlorate Ions: Experimental and Modeling Study

2021 ◽  
Vol 43 (5) ◽  
pp. 559-559
Author(s):  
Mahwish Mobeen Khan and Syed Mumtaz Danish Naqvi Mahwish Mobeen Khan and Syed Mumtaz Danish Naqvi
Keyword(s):  
Electron Transfer ◽  
Transfer Reaction ◽  
High Energy ◽  
Electron Transfer Reaction ◽  
Maximum Likelihood Estimates ◽  
Oxidation Catalyst ◽  
Standard Entropy ◽  
Rate Of Reaction ◽  
Kinetics Of ◽  
Activated Complex

This research article reports original experimental and modeling detail of kinetics of the electron transfer reaction between Co(II) and chlorate ions in acetic acid solution. Design of experiment methodology has been employed to elucidate the effects of temperature and initial concentrations of reactants on the rate of reaction. Levenberg-Marquardt method has been used to fit processed kinetic data (temperatures, initial concentrations of reactants, and concentrations and rates of production of Co(III)) on to various possible rate equations. This algorithm provides a proficient mean for compensating the capricious effects of the experimental process variables and results in the maximum likelihood estimates of the kinetic parameters. The most significant rate law has been selected, on the basis of statistical analyses of the residuals between the predicted and experimental rates. The analyses suggest that the intrinsic rate of reaction is proportional to first power of chlorate concentration but for Co(II) the order is fractional (0.7455 ≈ and#190;). The effect of temperature on the observed rate constant (precision = 0.02 %) is excellently described by the Arrhenius and Eyring equations and the sluggish nature of the reaction is clearly manifested by the high energy (andgt; 93 kJ/mol), negative entropy (-28.5286 J/mol-K) and very small equilibrium constant of activation. Further fairly negative standard entropy of activation shows there is usually considerable rearrangement of energy among various degrees of freedom during the formation of activated complex and proposes an associative mechanism for formation of the activated complex. This research is performed to develop a kinetic model for the electron transfer reaction between Co(II) and chlorate ion. As a result, a redox couple of Co(II)/Co(III) has been formed which is used as a potent oxidation catalyst in chemical industries.

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