Standard and reversible anodic potentials of the electrosynthesis of peroxodisulfates at 0–50 °C

2011 ◽  
Vol 76 (4) ◽  
pp. 343-350
Author(s):  
Jan Balej
Keyword(s):  
Activity Coefficients ◽  
Conversion Degree ◽  
Electrochemical Reactions ◽  
Reaction Conditions ◽  
Temperature Range ◽  
Ammonium Peroxodisulfate ◽  
Saturated Solutions

Standard potentials of the couples S2O82–/SO42– and S2O82–/HSO4– in the temperature range 0–50 °C and reversible anodic potentials of the electrosynthesis of peroxodisulfates at various initial concentrations of M2SO4 and H2SO4, various conversion degree of sulfate to peroxodisulfate in the same temperature range under neglecting the effect of activity coefficients of reaction components have been derived. Reversible anodic potentials of the electrosynthesis of almost saturated solutions of ammonium peroxodisulfate in the temperature range 10–40 °C under various reaction conditions have been calculated on taking into account the corresponding activity coefficients. It has been shown that the reversible anodic potentials under respecting activity coefficients of reaction components are by about 20–30 mV higher. The results of this contribution can be applied to all chemical or electrochemical reactions of peroxodisulfates.

Solubility in the System (NH4)2S2O8—NH3—H2O and Mean Activity Coefficients of Saturated Solutions of (NH4)2S2O8

2012 ◽  
Vol 5 (1) ◽  
pp. 12-14
Author(s):  
Jan Balej
Keyword(s):  
Activity Coefficient ◽  
Activity Coefficients ◽  
Pure Water ◽  
Relative Activity ◽  
Mean Activity Coefficient ◽  
The Mean ◽  
Water Values ◽  
Mean Activity Coefficients ◽  
Ammonium Peroxodisulfate ◽  
Saturated Solutions

Solubility in the System (NH4)2S2O8—NH3—H2O and Mean Activity Coefficients of Saturated Solutions of (NH4)2S2O8The solubility data of ammonium peroxodisulfate in aqueous ammonia solutions at 15.5 °C have been evaluated using the relative activity coefficient expansion. Using the known value of the mean activity coefficient of saturated solution of ammonium peroxodisulfate in pure water, values of the mean activity coefficients of this salt in the saturated solutions of the given system have been calculated.

Transformation of 1-Butene over Synthetic Zeolites

1992 ◽  
Vol 57 (4) ◽  
pp. 869-881 ◽  
Author(s):  
Italo Ferino ◽  
Roberto Monaci ◽  
Vincenzo Solinas ◽  
Lucio Forni ◽  
Antonio Rivoldini ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Continuous Flow ◽  
Liquid Mixture ◽  
Isomerization Reaction ◽  
Reaction Conditions ◽  
Title Reaction ◽  
Y Zeolites ◽  
Temperature Range ◽  
Flow Microreactor ◽  
Synthetic Zeolites

The behaviour of several zeolites as catalysts for the title reaction has been investigated by means of a continuous flow microreactor. Runs performed at atmospheric pressure indicated that at 423 K the completely protonic forms of the zeolites catalyze just the isomerization reaction. In the case of Y zeolites, oligomerization occurs only over the partially decationated samples, in the temperature range between 373 and 423 K and W/F between 0.2 and 22 gcath/g1-but, to an extent which depends on the reaction conditions. Most of the catalysts were tested also under pressure (4.05 MPa) at 423 K. The protonic forms of Y and ZSM-5 zeolites seem promising catalysts in terms of both conversion and selectivity to oligomers. The 1-olefins account for 30% of the entire olefinic mixture. The octenes, which account for 70% of the liquid mixture, are mostly formed of dimethylhexenes. Trimers are also formed during the reaction and, in the very particular case of H[B]ZSM-5, tetramers are produced.

scholarly journals Thermodynamic properties of the liquid Hg-Tl alloys determined from vapour pressure measurements

2002 ◽  
Vol 38 (3-4) ◽  
pp. 237-247 ◽  
Author(s):  
W. Gierlotka ◽  
K. Fitzner ◽  
M. Sukiennik
Keyword(s):  
Thermodynamic Properties ◽  
Activity Coefficients ◽  
Thermodynamic Functions ◽  
Vapour Pressure ◽  
Pressure Measurements ◽  
Temperature Range ◽  
Liquid Solutions ◽  
Partial Vapour Pressure

The partial vapour pressure of mercury over liquid Hg-Tl liquid solutions were determined in the temperature range from 450 to 700 K by direct vapour pressure measurements carried out with the quartz gauge. From the measured ln pHg vs. T relationships activities of mercury were determined. Using Redlich-Kister formulas logarithms of the activity coefficients were described with the following equations: From which all thermodynamic functions in the solutions can be derived.

Physical Interpretation of Solubility Interaction Constants from the Series Expansion of the Relative Activity Coefficients

1994 ◽  
Vol 59 (9) ◽  
pp. 1911-1921 ◽  
Author(s):  
Jaroslav Nývlt ◽  
Jitka Eysseltová
Keyword(s):  
Activity Coefficient ◽  
Series Expansion ◽  
Activity Coefficients ◽  
Physical Interpretation ◽  
Ternary Systems ◽  
Relative Activity ◽  
Solubility Data ◽  
Close Relationship ◽  
Insight Into ◽  
Saturated Solutions

Hydration analysis, which enables information on ionic processes in saturated solutions to be derived from solubility data in ternary systems, was applied to the interpretation of solubility interaction constants from the relative activity coefficient expansion. A close relationship was found between the hydration analysis parameters and the solubility interaction constants characterizing the relative activity of solute, which extends our insight into the ionic behaviour of the system studied by using the values of the interaction constants.

Solvolysis of Sulphonyl Halides. II. The Alcoholysis of Aromatic Sulphonyl Chlorides in Ethanol-Acetone and Methanol-Acetone

1961 ◽  
Vol 14 (2) ◽  
pp. 205 ◽  
Author(s):  
FE Jenkins ◽  
AN Hambly
Keyword(s):  
Experimental Temperature ◽  
Isokinetic Temperature ◽  
Reaction Conditions ◽  
Temperature Range ◽  
Experimental Temperature Range

The solvolysis of aromatic sulphonyl chlorides in methanol-acetone and ethanol-acetone shows only small, irregular effects due to para-substituents because the experimental temperature range is close to the isokinetic temperature. The modification of reaction conditions in SN2 substitutions, so that the isokinetic condition is brought into the experimental temperature range, is discussed. Rates for methanolysis are lower than those for hydrolysis and are about four times the rates for the corresponding ethanolysis reactions.

scholarly journals Mean Activity Coefficients of Peroxodisulfates in Saturated Solutions of the Conversion System 2NH4+ — 2Na+ — S2O8 2– — SO4 2– — H2O at 20 °C and 30 °C

2013 ◽  
Vol 6 (2) ◽  
pp. 163-167
Author(s):  
Jan Balej
Keyword(s):  
Activity Coefficient ◽  
Activity Coefficients ◽  
Relative Activity ◽  
Solubility Data ◽  
Correlation Equations ◽  
Conversion System ◽  
Mean Activity Coefficients ◽  
Saturated Solutions

Abstract Solubility data of the conversion system 2NH4+ - 2Na+ - S2O82- - SO42- - H2O at 20 °C and 30 °C for the partial pseudoternary systems Na2S2O8-(NH4)2SO4-H2O, (NH4)2S2O8-Na2SO4-H2O, Na2S2O8-NaNH4SO4-H2O and (NH4)2S2O8-NaNH4SO4-H2O have been correlated using the relative activity coefficient expansion of the crystallizing component. The obtained correlation equations have been used for the calculation of mean activity coefficients of ammonium and sodium peroxodisulfates in their saturated solutions of the mentioned pseudoternary systems.

scholarly journals Impact of Testing Temperature on the Structure and Catalytic Properties of Au Nanotubes Composites

2018 ◽  
Vol 13 (3) ◽  
pp. 405 ◽  
Author(s):  
Anastassiya A. Mashentseva ◽  
Maxim V. Zdorovets ◽  
Daryn B. Borgekov
Keyword(s):  
Catalytic Properties ◽  
Comprehensive Evaluation ◽  
Average Crystallite Size ◽  
Testing Temperature ◽  
Conversion Degree ◽  
Composite Catalyst ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Track Membranes

In the paper, the catalytic activity of composites based on gold nanotubes and ion track membranes was studied using bench reaction of the p-nitrophenol (4-NP) reduction in the temperature range of 25-40 °C. The efficiency of the prepared catalysts was estimated on the rate constant of the reaction and by conversion degree of 4-NP to p-aminophenol (4-AP). The comprehensive evaluation of the structure was performed by X-ray diffraction and scanning electron microscopy. A decreasing of the composites activity was observed when the reaction were carried out at the temperature over 35 °C, due to an increased average crystallite size from 7.31±1.07 to 10.35±3.7 nm (after 1st run). In temperature range of 25-35 °C the efficiency of the composite catalyst was unchanged in 3 runs and decreases by 24-32 % after the 5th run. At the high temperature of 40 °C after the 5th run the composite become completely  catalytically inert. Copyright © 2018 BCREC Group. All rights reservedReceived: 23rd January 2018; Revised: 19th March 2018; Accepted: 19th March 2018How to Cite: Mashentseva, A.A., Zdorovets, M.V., Borgekov, D.B. (2018). Impact of Testing Temperature on the Structure and Catalytic Properties of Au Nanotubes Composites. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (3): 405-411 (doi:10.9767/bcrec.13.3.2127.405-411)Permalink/DOI: https://doi.org/10.9767/bcrec.13.3.2127.405-411 

scholarly journals Methane Conversion over Vacuum Carbon Black: Influence of Hydrogen

2017 ◽  
Vol 3 (3) ◽  
pp. 163 ◽  
Author(s):  
S.D. Kushch ◽  
V.E. Muradyan ◽  
N.S. Kuyunko
Keyword(s):  
Carbon Black ◽  
Methane Conversion ◽  
Heterogeneous Reaction ◽  
Pyrolytic Carbon ◽  
Conversion Degree ◽  
Carbon Formation ◽  
Initial Concentration ◽  
Temperature Range ◽  
The One ◽  
Methane Pyrolysis

<p>Methane pyrolysis over vacuum carbon black has been studied in the temperature range 550–1000 °C. The methane conversion degree and selectivity with respect to ethene and propene do not depend on the initial concentration of methane <em>i.e. </em>the process order with respect to methane is first. The selectivity with respect to pyrolytic carbon is antibate to the methane initial concentration. Hydrogen introduced to methane inhibits formation of pyrolytic carbon and aromatics especially in methane pyrolysis. The methane conversion degree in pyrolysis of methane/hydrogen mixture is inversely proportional to the initial concentration of hydrogen while the selectivity with respect to ethene being symbate to the one. A hypothesis on the reason of inhibition of pyrolytic carbon formation by hydrogen is proposed. Methane pyrolysis is a homogeneous-heterogeneous reaction up to 850°C, but homogeneous reaction is prevalent at the temperature range of maximal selectivity with respect to alkenes.</p>

scholarly journals Improved AIOMFAC model parameterisation of the temperature dependence of activity coefficients for aqueous organic mixtures

2014 ◽  
Vol 14 (11) ◽  
pp. 16907-16995 ◽  
Author(s):  
G. Ganbavale ◽  
A. Zuend ◽  
C. Marcolli ◽  
T. Peter
Keyword(s):  
Temperature Dependence ◽  
Functional Groups ◽  
Activity Coefficients ◽  
Low Temperatures ◽  
Functional Group ◽  
Group Contribution ◽  
Organic Mixtures ◽  
Temperature Range ◽  
Organic Functional Groups ◽  
Organic Solutions

Abstract. This study presents a new, improved parameterisation of the temperature dependence of activity coefficients in the AIOMFAC (Aerosol Inorganic–Organic Mixtures Functional groups Activity Coefficients) model applicable for aqueous as well as water-free organic solutions. For electrolyte-free organic and organic–water mixtures the AIOMFAC model uses a group-contribution approach based on UNIFAC (UNIversal quasi-chemical Functional-group Activity Coefficients). This group-contribution approach explicitly accounts for interactions among organic functional groups and between organic functional groups and water. The previous AIOMFAC version uses a simple parameterisation of the temperature dependence of activity coefficients, aimed to be applicable in the temperature range from ~275 to ~400 K. With the goal to improve the description of a wide variety of organic compounds found in atmospheric aerosols, we extend the AIOMFAC parameterisation for the functional groups carboxyl, hydroxyl, ketone, aldehyde, ether, ester, alkyl, aromatic carbon-alcohol, and aromatic hydrocarbon to atmospherically relevant low temperatures with the introduction of a new temperature dependence parameterisation. The improved temperature dependence parameterisation is derived from classical thermodynamic theory by describing effects from changes in molar enthalpy and heat capacity of a multicomponent system. Thermodynamic equilibrium data of aqueous organic and water-free organic mixtures from the literature are carefully assessed and complemented with new measurements to establish a comprehensive database, covering a wide temperature range (~190 to ~440 K) for many of the functional group combinations considered. Different experimental data types and their processing for the estimation of AIOMFAC model parameters are discussed. The new AIOMFAC parameterisation for the temperature dependence of activity coefficients from low to high temperatures shows an overall improvement of 25% in comparison to the previous model version. The new parameterisation of AIOMFAC agrees well with a large number of experimental datasets and enables the calculation of activity coefficients of a wide variety of different aqueous/water-free organic solutions down to the low temperatures present in the upper troposphere.

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