ChemInform Abstract: SOLVOLYSIS RATES IN AQUEOUS ORGANIC MIXED SOLVENTS. VIII. ENTHALPY AND ENTROPY OF ACTIVATION FOR BENZOYL CHLORIDE SOLVOLYSIS IN ISOPROPYL ALCOHOL-WATER SOLVENT MIXTURES

1980 ◽  
Vol 11 (13) ◽  
Author(s):  
E. M. DIEFALLAH ◽  
M. A. MOUSA ◽  
M. A. ASHY ◽  
S. A. GHONAIM
Keyword(s):  
Benzoyl Chloride ◽  
Isopropyl Alcohol ◽  
Mixed Solvents ◽  
Solvent Mixtures ◽  
Water Solvent ◽  
Alcohol Water ◽  
Entropy Of Activation ◽  
Enthalpy And Entropy ◽  
Aqueous Organic Mixed Solvents

Enthalpy and entropy of activation for benzyl chloride solvolysis in various alcohol–water solvent mixtures

1968 ◽  
Vol 46 (2) ◽  
pp. 125-129 ◽  
Author(s):  
H. S. Golinkin ◽  
J. B. Hyne
Keyword(s):  
Rate Constants ◽  
Benzyl Chloride ◽  
Solvent Composition ◽  
Solvent Mixtures ◽  
Methyl Ethyl ◽  
First Order ◽  
Water Solvent ◽  
Alcohol Water ◽  
Entropy Of Activation ◽  
Enthalpy And Entropy

The first order rate constants for the solvolysis of benzyl chloride in a series of mixtures of methyl, ethyl, i-propyl, and t-butyl alcohols with water are reported at 40.05 and 60.50 °C. The ΔH* and ΔS* values are calculated using these rate constants and those previously reported at 50.25 °C (1, 2). The dependence of these parameters on solvent composition is discussed.

Solvolysis rates in aqueous – organic mixed solvents. V. Kinetics of the alkaline decarboxylation of trichloroacetate ion in water – ethanol solutions

1978 ◽  
Vol 56 (15) ◽  
pp. 2053-2057 ◽  
Author(s):  
El-Hussieny M. Diefallah ◽  
A. M. El-Nadi
Keyword(s):  
Mole Fraction ◽  
Pure Water ◽  
Mixed Solvents ◽  
Activation Parameters ◽  
Solvent Mixtures ◽  
Rate Of Reaction ◽  
Ethanol Addition ◽  
Regular Increase ◽  
Aqueous Organic Mixed Solvents ◽  
Kinetics Of

The kinetics of the alkaline decarboxylation of trichloroacetate ion in ethanol–water solutions have been studied over the temperature range 35.0 to 70.0 °C. The rate of reaction is first order with respect to the trichloroacetate ion and is independent of the concentration of the hydroxide ion. The reactivity is enhanced by increasing the concentration of ethanol in the water–ethanol solutions and the rate of reaction varies with ethanol addition in a nonlinear manner. The rate of reaction increases with the reciprocal of the dielectric constant of the medium and the plot of log k vs. 1/D is approximately linear for solvent mixtures with less than about 0.7 water mole fraction but is strongly curved towards the pure water end. The activation parameters for the reaction show a regular increase in the solvent composition range 0.3 to 1.0 water mole fraction. The results are discussed in terms of the influence of solvent internal pressure and polarity on reactivity and of the increased amount of hydrogen-bonded structure in the water-rich solutions.

Phosphorylation of Ca2+-ATPase by Inorganic Phosphate in Water-Organic Solvent Media: Dielectric Constant and Solvent Hydrophobicity Contribution

1982 ◽  
Vol 37 (5-6) ◽  
pp. 527-531 ◽  
Author(s):  
Angela de Souza Otero ◽  
Leopoldo de Meis
Keyword(s):  
Dielectric Constant ◽  
Organic Solvent ◽  
Inorganic Phosphate ◽  
Mixed Solvents ◽  
Solvent Mixtures ◽  
Pronounced Increase ◽  
Calcium Gradient ◽  
Organic Solvent Media ◽  
Water Solvent ◽  
Reaction In Water

Abstract The effect of organic solvents on the phosphorylation of the Ca2+-dependent ATPase of sarcoplasmic reticulum by inorganic phosphate in the absence of a calcium gradient was investigated. Kinetic analysis of the reaction in water and water-organic solvent media according to a bireactant scheme shows no correlation between changes in kinetic parameters and the dieletric constant of the mixed solvents. The pronounced increase in equilibrium levels of phosphoenzyme in water-solvent mixtures is attributed to changes in the water activity of the medium.

scholarly journals The Solubility of Lead Sulfate in n-Propyl Alcohol-Water and Isopropyl Alcohol-Water Mixed Solvents

1959 ◽  
Vol 80 (1) ◽  
pp. 4-7 ◽  
Author(s):  
Ei KOIZUMI ◽  
Hiroshi MIYAMOTO ◽  
Hiromichi YANAI ◽  
Iwao YONETA
Keyword(s):  
Isopropyl Alcohol ◽  
Mixed Solvents ◽  
Lead Sulfate ◽  
Propyl Alcohol ◽  
Alcohol Water

Solvent structure effects on solvated electron reactions with ions in 2-butanol/water mixed solvents

1991 ◽  
Vol 69 (5) ◽  
pp. 884-892 ◽  
Author(s):  
Sedigallage A. Peiris ◽  
Gordon R. Freeman
Keyword(s):  
Rate Constant ◽  
Pure Water ◽  
Mixed Solvents ◽  
Reaction Rates ◽  
Bimolecular Reaction ◽  
Activation Energies ◽  
Solvated Electron ◽  
Polar Species ◽  
Water Solvent ◽  
Alcohol Water

The Smoluchowski–Debye–Stokes–Einstein equation for the rate constant k2 of a bimolecular reaction between charged or polar species[Formula: see text]was used to evaluate effects of bulk solvent properties on reaction rates of solvated electrons with [Formula: see text] and [Formula: see text] in 2-butanol/water mixed solvents. To explain detailed effects it was necessary to consider more specific behavior of the solvent. Rate constants k2, activation energies E2, and pre-exponential factors A2 of these reactions vary with the composition of 2-butanol/water mixtures. The values of E2 were in general similar to activation energies of ionic conductance EΛ0 of the solutions, except for much higher values of E2 of [Formula: see text] in alcohol-rich solvents and of [Formula: see text] in pure water solvent. The solvent apparently participates chemically in the [Formula: see text] reaction, and the [Formula: see text] reaction is multistep. Rate constant and conductance measurements of thallium acetate solutions in 2-butanol containing zero and 10 mol% water were complicated by the formation of ion clusters larger than pairs. Key words: alcohol/water mixed solvents, ions, reaction kinetics, solvated kinetics, solvated electron, solvent effects.

Solubility and Thermoresponsiveness of PMMA in Alcohol-Water Solvent Mixtures

2010 ◽  
Vol 63 (8) ◽  
pp. 1173 ◽  
Author(s):  
Richard Hoogenboom ◽  
C. Remzi Becer ◽  
Carlos Guerrero-Sanchez ◽  
Stephanie Hoeppener ◽  
Ulrich S. Schubert
Keyword(s):  
Methyl Methacrylate ◽  
Pure Water ◽  
Polymer Concentration ◽  
Polymer Processing ◽  
Solution Temperature ◽  
Solvent Mixtures ◽  
Poly Methyl Methacrylate ◽  
Water Solvent ◽  
Alcohol Water ◽  
Hysteresis Behaviour

To reduce the environmental burden of polymer processing, the use of non-toxic solvents is desirable. In this regard, the improved solubility of poly(methyl methacrylate) (PMMA) in ethanol/water solvent mixtures is very appealing. In this contribution, detailed investigations on the solubility of PMMA in alcohol/water solvent mixtures are reported based on turbidimetry measurements. PMMA revealed upper critical solution temperature transitions in pure ethanol and ethanol/water mixtures. However, around 80 wt-% ethanol content a solubility maximum was observed for PMMA as indicated by a decrease in the transition temperature. Moreover, the transition temperatures increased with increasing PMMA molar mass as well as increasing polymer concentration. Careful analysis of both heating and cooling turbidity curves revealed a peculiar hysteresis behaviour with a higher precipitation temperature compared with dissolution with less than 60 wt-% or more than 90 wt-% ethanol in water and a reverse hysteresis behaviour at intermediate ethanol fractions. Finally, the transfer of poly(styrene)-block-poly(methyl methacrylate) block copolymer micelles from the optimal solvent, i.e. aqueous 80 wt-% ethanol, to almost pure water and ethanol is demonstrated.

Chlorine isotope effects in the solvolysis of substituted 1-phenylethyl chlorides

1986 ◽  
Vol 64 (6) ◽  
pp. 1201-1205 ◽  
Author(s):  
Duncan J. McLennan ◽  
Allan R. Stein ◽  
Brian Dobson
Keyword(s):  
Transition State ◽  
Theoretical Calculations ◽  
Isotope Effects ◽  
Chloride Ion ◽  
Solvent Composition ◽  
Solvent Mixtures ◽  
Chlorine Isotope ◽  
Water Solvent ◽  
Alcohol Water ◽  
Substituted 1

Kinetic chlorine isotope effects attending the solvolysis of several ring-substituted 1-phenylethyl chlorides in alcohol–water solvent mixtures are reported. The k35/k37 values are insensitive to the identity of ring substituents and to solvent composition. Results are interpreted in terms of an SN1 heterolytic process incorporating a significant amount of internal return. Theoretical calculations suggest that the incipient chloride ion in the transition state may be strongly hydrogen-bonded.

scholarly journals Solvation enthalpy of uranium tetrachloride in aqueous-alcohols mixed solvents

2017 ◽  
Vol 17 (3) ◽  
pp. 122-127
Author(s):  
Raghvendu Pathak
Keyword(s):  
Mixed Solvents ◽  
Crystalline Solid ◽  
Solvent Mixtures ◽  
Covalent Bonds ◽  
Crystal Lattices ◽  
Solvation Enthalpy ◽  
Alcohol Water ◽  
Aqueous Solvent ◽  
Solvent Molecules ◽  
Uranium Tetrachloride

The process of interaction between ions of a solute and the molecules of the solvent through relatively weak covalent bonds is called solvation. It involves evening out a concentration gradient and evenly distributing the solute molecules within the solvent. Hydration is a special case of solvation when the solvent molecules are water. Solvation energy, generally, is the energy released when ions in crystal lattices associate with molecules in a solvent, however it can be positive or negative, depending upon the combined effects of lattice and hydration energies in case of aqueous-ionic solid dissolution. Uranous chloride or uranium tetrachloride (UCl4) is a green crystalline solid which sublimes in vacuum at 500°C/10-3 mm. It is a Lewis acid and hence dissolves in solvents which can act as non-protic Lewis bases. Although dissolution of uranium tetrachloride crystals in water is an exothermic process yielding a green solution which is fairly stable in the cold, yet is hydrolyzed to a considerable extent to furnish an acidic reaction. Solvation enthalpies of quadrivalent uranium system have been scantly reported. The present communication deals with the calculation of enthalpy of solution of uranium tetrachloride in aqueous-non-aqueous solvent mixtures, particularly in 10 and 20 weight (wt) % methyl alcohol-water and ethyl alcohol-water systems at 25°C calorimetrically and thereby estimating the solvation enthalpy of UCl4 in the said media.

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