Mole Fraction Of Acetic Acid Research Articles

Electronic States of Acetic Acid in a Binary Mixture of Acetic Acid and 1-Methylimidazole Depend on the Environment.

The unique characteristics of an acetic acid/1-methylimidazole (1-MI) mixture, showing higher electrical conductivity than either neat acetic acid or neat 1-MI, yet consisting of electrically neutral molecules, are reported. We have applied soft X-ray spectroscopy to reveal the electronic states of acetic acid in the acetic acid/1-MI mixture at various mole fractions of acetic acid (χHOAc). The results show that the amount of acetic acid monomer increases in the region of especially high electrical conductivity and the amount of complex of acetic acid and 1-MI formed by sharing molecular orbitals increases in the low electrical conductivity region. There is a little amount of acetic acid monomer in the low electrical conductivity region because the complex inhibits acetic acid from creating its monomer. These results suggest the possibility that the acetic acid monomer is related to electrical conduction.

Solute–Solvent Interaction of Benzene with Acetic Acid at Different Temperatures

The present paper reports a study of binary mixtures of benzene and acetic acid over the entire range of composition at temperatures of 288, 298, 308 and 318 K. The measured values of static dielectric constant, density, and refractive index of the binary mixtures are further used to evaluate the excess dielectric constant, excess molar volume, excess refractive index, molar and excess molar refraction at these temperatures. The values of excess dielectric constant and excess refractive index are positive whereas the excess molar volume is negative over the entire range of mole fractions of acetic acid. The results are discussed in light of the intermolecular interactions occurring between the benzene and acetic acid molecules. The excess parameters were fitted with the Redlich–Kister equation and the resulting estimated Redlich–Kister coefficients (a j ) and standard deviations are reported.

Solubilities of Isophthalic Acid in Acetic Acid + Water Solvent Mixtures

The solubilities of isophthalic acid (1) in binary acetic acid (2) + water (3) solvent mixtures were determined in a pressurized vessel. The temperature range was from 373.2 to 473.2K and the range of the mole fraction of acetic acid in the solvent mixtures was from x2 = 0 to 1. A new method to measure the solubility was developed, which solved the problem of sampling at high temperature. The experimental results indicated that within the temperature range studied, the solubilities of isophthalic acid in all mixtures showed an increasing trend with increasing temperature. The experimental solubilities were correlated by the Buchowski equation, and the calculate results showed good agreement with the experimental solubilities. Furthermore, the mixed solvent systems were found to exhibit a maximum solubility effect on the solubility, which may be attributed to the intermolecular association between the solute and the solvent mixture. The maximum solubility effect was well modeled by the modified Wilson equation.

New Group-Interaction Parameters of the UNIFAC Model: Aromatic Carboxyl Binaries

The solubility of p-toluic acid (PTA) in acetic acid (HOAc) + water solvent mixtures was measured by a static method. The experimental temperature ranged from 303.2 to 363.2 K, and the mole fraction of acetic acid in the solvent mixtures ranged from 0.546 to 1.000. Together with the available solid−liquid equilibrium (SLE) data for ternary systems of terephthalic acid (TPA) + HOAc + H2O and benzoic acid (BA) + HOAc + H2O, the interaction parameters of the new UNIFAC group ArCOOH, defined as an aromatic group (Ar) plus an (aromatic) carboxyl group (COOH), with an aliphatic carboxyl group (COOH), methyl group (CH3 and CH2), aromatic group (Ar), aromatic methyl group (ArCH3), and water are determined. By using the new defined group ArCOOH, the UNIFAC model predicted SLE data for the above three ternary systems agree with the experimentally determined results satisfactorily.

Solubilities of 1,3,5-Benzenetricarboxylic Acid and 1,3-Benzenedicarboxylic Acid in Acetic Acid + Water Solvent Mixtures

Using the static analytical method, the solubilities of 1,3,5-benzenetricarboxylic acid and 1,3-benzenedicarboxylic acid in binary acetic acid (2) + water (3) solvent mixtures have been measured. The experimental temperature ranged from (303.2 to 363.2) K, and the mole fraction of acetic acid in the solvent mixtures ranged from (0.411 to 1.000) for 1,3,5-benzenetricarboxylic acid and x2 = (0.310 to 1.000) for 1,3-benzenedicarboxylic acid. The experimental results showed that, within the temperature range of the measurements, the solubilities of 1,3,5-benzenetricarboxylic acid and 1,3-benzenedicarboxylic acid in all the mixtures showed an increasing trend as the temperature increased. The solubility of 1,3,5-benzenetricarboxylic acid increased with the increasing mole fraction of water. Below 323.2 K, as the mole fraction of water increased in the aqueous acetic acid solution, the solubility of 1,3-benzenedicarboxylic acid decreased within the range of measurements. However, above 323.2 K, the aqueous acetic acid solution, of which the mole fraction of acetic acid was 0.544, was the best solvent for 1,3-benzenedicarboxylic acid. A simple explanation was given for this “maximum-solubility effect”. The present results were compared with the data obtained from our previous work. The experimental solubilities had been correlated with the Buchowski equation, and the calculated results showed good agreement with the experimental solubilities.

Solubility of 1,2,4-Benzenetricarboxylic Acid in Acetic Acid + Water Solvent Mixtures

Using the static analytical method, the solubility of 1,2,4-benzenetricarboxylic acid in binary acetic acid + water solvent mixtures has been measured. The experimental temperatures range from (313.2 to 363.2) K, and the mole fractions of acetic acid in the solvent mixtures range from 0.416 to 1.000. The experimental solubilities were correlated by the Apelblat equation.

Electrochemical oxidation of substituted benzylamines in aquo-acetic acid medium: substituent and solvent effects

Electrochemical oxidation of nine para- and meta-substituted benzylamines in varying mole fractions of acetic acid in water has been investigated in the presence of 0.1 M sulphuric acid as supporting electrolyte. The oxidation potentials correlate well with Hammett’s substituent constants affording negative reaction constants. The correlation of potential values with macroscopic solvent parameters is non-linear suggesting that the operation of both specific and non-specific solvent-solvent-solute interaction mechanisms. Multiple correlation analysis of the experimental data with Kamlet-Taft solvatochromic parameters is employed.

Substituent and Solvent Effects on the Electrochemical Oxidation of para- and meta-Substituted Anilines

Electrochemical oxidation of fifteen para- and meta-substituted anilines in different mole fractions of acetic acid in water has been investigated in the presence of 0.1 M sulphuric acid as supporting electrolyte. The oxidation potential data of anilines correlates well with Hammett’s and Brown- Okamoto’s substituent constants affording negative reaction constants. The effect of para- and metasubstituents on the oxidation potential conforms to Swain’s F and R parameters, affording negative reaction constants. The oxidation potential values correlate well with macroscopic solvent parameters such as relative permittivity, εr, and polarity, ET N. Multiple correlation analysis also shows an excellent correlation with the oxidation potential values.

Solvent effects on the kinetics of oxidation of methionine by nicotinium dichromate

The oxidation of methionine by nicotinium dichromate (NDC) has been studied, in the presence of p-toluene sulphonic acid, in water-DMSO and water-acetic acid mixtures of varying mole fractions. The reaction is first order each with respect to NDC and acid. The reaction rates have been determined at different temperatures and the activation parameters have been computed. The rate of decomposition of the complex increases with increase in mole fraction of acetic acid in the mixture while in water-DMSO mixtures the rate decreases with increasing mole fraction of the organic co-solvent. A possible mechanism for the reaction is postulated.

Solvation model for the oxidation of methionine by imidazolium fluorochromate in aqueous acetic acid medium

The oxidation of methionine by imidazolium fluorochromate (IFC) were studied, in the presence of chloroacetic acid, in water-acetic acid mixtures of varying molar compositions. The reaction is first order with respect to methionine, IFC and acid. The reaction rates were determined at different temperatures and the activation parameters were computed. The reaction rate increases with increasing mole fraction of acetic acid in the mixture and specific solvent-solvent-solute interactions were found to predominate (86 %). A solvation model and a probable mechanism for the reaction are postulated.

Contrasting solvent effects on the kinetics of oxidation of methionine by quinolinium fluorochromate

The oxidation of methionine by quinolinium fluorochromate (QFC) has been studied, in the presence of chloroacetic acid. in water-DMSO and water-acetic acid mixtures of varying mole fractions. The reaction is first order each with respect to methionine, QFC and acid. The reaction rates have been determined at different temperatures and the activation parameters have been computed. The reaction rate increases with increase In mole fraction of acetic acid in the mixture, where the specific solvent-solvent-solute interactions were found to dominant (56%), while In water-DMSO mixtures the rate decreases with increasing mole fraction of the organic co-solvent, where the transition state was stabilized only to a lesser extent by solvation. A solvation model and a suitable mechanism for the reaction are postulated.

Kinetics and mechanism of the oxidation of methionine by quinolinium chlorochromate

The oxidation of methionine by quinolinium chlorochromate (QCC) has been studied, in the presence of chloroacetic acid, and in water-acetic acid mixtures of varying mole fractions. The reaction is first order with respect to methionine, QCC and acid. The reaction rates were determined at three different temperatures (25, 35 and 45 ?C) and the activation parameters were computed. The reaction rate increased with increasing mole fraction of acetic acid in the mixture and specific solvent-solvent-solute interactions were found to predominate (81 %). A solvation model and a suitable mechanism for the reaction are postulated.

Excess molar volume, viscosity and thermodynamics of viscous flow of the system dimethylsulfoxide and acetic acid

Densities and viscosities for the system dimethylsulfoxide (DMSO) and acetic acid, CH 3COOH, have been determined for the whole range of composition at temperatures ranging from 303.15 to 328.15 K. Density, excess molar volume, viscosity, viscosity deviation, free energy and excess free energy of activation for viscous flow have been plotted against the mole fraction of acetic acid. Results suggest the presence of strong specific interactions between the component molecules, and further that a complex is formed in the ratio 1 DMSO:2 CH 3COOH.

Excess molar enthalpies of binary mixtures containing acetic or propionic acid+eight ethyl alkanoates at 298.15 K

Excess molar enthalpies, H E m of binary mixtures containing acetic or propionic acid+eight ethyl alkanoates have been determined at 298.15 K using a flow microcalorimeter. H E m values have been found to be positive with the exception of the acetic acid+ethyl acetate mixtures where an inversion of sign from positive to negative values occurs at the mole fraction of acetic acid x 1≈0.62 J mol −1. H E m values vary in the range from −30 to 440 J mol −1. The experimental results have been correlated using the Redlich–Kister equation.

Low-frequency Raman spectra of crystalline and liquid acetic acid and its mixtures with water.: Is the liquid dominated by hydrogen-bonded cyclic dimers?

Low-frequency Raman spectra of crystalline and liquid acetic acid, and acetic acid–water binary solutions with varying mole fractions of acetic acid ( x A), are presented in the form of the relative scattering activities, R( ν ̄ ) spectra. The spectrum of scattered light I( ν ̄ ) from crystalline acetic acid at 285 K shows five distinctive bands. Upon the melting, however, the liquid exhibited conspicuous difference in its appearance, although the R( ν ̄ ) spectrum shows two peaks and a shoulder at similar wavelengths to those of the crystalline bands. The spectral change does not directly support the dominance of the cyclic dimers in the liquid. R( ν ̄ ) spectra of acetic acid–water binary solutions suggest a three-state model composed of acetic acid associates, binary associates and water associates for the local structure of the mixtures.

Ultrasound absorption in acetic acid-tetrachzoromethane mixture

Abstract Absorption of ultrasonic waves has been investigated in the mixture of acetic acid and tetrachloromethane covering the complete concentration range. Measurements have been carried out at 20, 30 and 40°C within a frequency range from 3 to 57 MHz for strongly absorbing mixtures (rich in acetic acid) and 5–57 MHz for mixtures with lower absorption. At about 0.01 mole fraction of acetic acid a relaxation has been observed with a relaxation frequency of 20 MHz increasing rapidly with increasing concentration, so that its observation has become impossible at mole fractions of acid bigger than 0.07. At higher acid concentrations the well known low frequency relaxation has been observed. The relaxations are discussed in terms of coupled dimerization and cyclization reaction of acetic acid including the nonideality of the mixture. In this model the faster relaxation seems to be caused by the dimerization reaction.

Notizen:Mischungsenthalpien beim flüssigen System Wasser + Essigsäure / Heats of Mixing for the Liquid System Water + Acetic Acid

Calorimetric measurements of the heats of mixing for the liquid system water+acetic acid at 17 °C, 20 °C, 25 °C, 30 °C, 40 °C, and 50 °C show that there is a change of sign in the function H̅E(x), where H̅E denotes the molar heat of mixing and x the mole fraction of acetic acid. The process of mixing the pure liquid components is weakly exothermic for low acid concentrations, but strongly endothermic for high acid concentrations. The function H̅E can be approximately represented by the usual power series with respect to x, five free parameters at each temperature being necessary.