Ethanol aqueous solution data

Fig. 20 Log EM for interaction of end-groups on polymer chains with average polymerisation degree 3c (i) pyridine-catalysed hydrolysis of the p-nitrophenyl ester group of [27] ( ) and [28] ( ) in aqueous solution (data from Sisido et at., 1976, 1978), (f i) intramolecular charge-transfer complexes of [29] in chloroform ( ) and in ethanol (O). (Data from Sisido et at., 1977 Takagi et at., 1977)...

The ultraviolet absorption spectrum of thiazole was first determined in 1955 in ethanolic solution by Leandri et al. (172), then in 1957 by Sheinker et al. (173), and in 1967 by Coltbourne et al. (174). Albert in 1957 gave the spectrum in aqueous solution at pH 5 and in acidic solution (NHCl) (175). Nonhydroxylic solvents were employed (176, 177), and the vapor-phase spectrum was also determined (123). The results summarized in Table 1-15 are homogeneous except for the first data of Leandri (172). Both bands A and B have a red shift of about 3 nm when thiazole is dissolved in hydrocarbon solvents. This red shift of band A increases when the solvent is hydroxylic and, in the case of water, especially when the solution becomes acidic and the extinction coefficient increases simultaneously. 

The ultraviolet spectra of the pyridinecarboxylic acids (334) were initially interpreted assuming that the proportion of the zwitterion structure 335 was not appreciable,and the early pK work was inconclusive. However, Jaffe s calculations based on the Hammett equation indicated that about 95% of nicotinic and isonicotinic acids existed in the zwitterion form, and ultraviolet spectral data showed that the actual percentages of picolinic, nicotinic, and isonieotinie acids existing in the zwitterion form in aqueous solution are 94, 91, and 96%, respectively.This was later confirmed by Stephenson and Sponer, who further demonstrated that the proportion of the zwitterion form decreases in solvents of low dielectric constant, becoming very low in ethanol. Dipole moment data indicate that isonicotinic acid exists as such in dioxane, and 6-hydroxypyridine-3-carboxyiic acid has been shown to exist in form 336 u.sing pK data. ... 

Let us suppose that the acetic acid content of the final aqueous solution is 5%, corresponding to a ratio of approximately 1 mol of CH3COOH to 60 mol of H2O. As the yield of reaction 2.1 will be near 100% (recall that reaction 2.2 is rather exothermic, implying a very high equilibrium constant see section 2.9), the same value will be used for the molar ratio (H2 O) / n (C 2115OII), despite the increased total amount of substance of water in the reaction products. In the present case, the difference of 1 mol of water between the product and the reactant mixtures has a negligible enthalpic effect. The enthalpies associated with the solution of ethanol and acetic acid in 60 mol of water are derived from literature data [17] as Asin//(1) = -10.0 0.1 kJ mol-1 and Asin//(3) = —1.0 0.1 kJ mol-1. This calculation will be detailed in section 2.5. 

Munder, B., Lidal, H., and Sandall, O.C. Physical solubility of hydrogen sulfide in aqueous solutions of 2-(tert-butylamino)ethanol, J. Chem. Eng. Data, 45(6) 1201-1204, 2000. 

Pedrosa, A. and Serrano, M.L. Solubilities of sodium gluconate in water and in aqueous solutions of ethanol and methanol, /. Chem. Eng. Data, 45(3) 461-463, 2000. 

Properties of EthanolIc Fructose Solutions. Published information on the properties of aqueous ethanolic fructose solution is very limited. As a result, solubility data from 25 to 60 °C was measured (Figure 1) and will be published separately. The equilibrium fructose/water mass ratio for zero alcohol, ranges from over 4 at 25 C to over 8 at 60 C (7,8). It can be seen that reasonable yields will only result with high alcohol additions (E/W at least 2). This is the range used in this study. Aqueous ethanolic solutions have a wide range of viscosities. These were measured at operating conditions using a Rheomat concentric cylinder viscometer. 

Shown below are some data concerning light absorption in the uv/vis range by pentachlorophenol (PCP). Absorption values for the neutral species are given in ethanol, those for the dissociated species at pH 10 in aqueous solution. 

Wammes et al. [34], by employing three different liquids (water - ethanol and 40 % ethyleneglycol aqueous solution) with 3 mm glass spheres, obtained experimentally determined static hold-up data. Figure 5.2-24 shows the values of the static holdup as a function of the Eotvos number together with data of other authors. Wammes et al. [34] concluded that the static liquid hold-up is not affected by the total reactor pressure. 

The data thus provided good evidence for the existence of preponderantly 1 1 sucrose-alkali metal salt adduct in aqueous solutions of low to moderate concentration of salt. Similar studies of n-fructose with alkali metal salts have given identical results. 0 In anhydrous ethanolic media,10 potassium acetate and methyl j3-D-glucopyranoside have been shown polarimetrically to combine in the ratio of 1 1. This ratio is also found in the adduct isolated. 

By conducting further experiments in different solvents, such as acetone, isopropanol, ethanol, and toluene, it was found that application of APS from an aqueous solution gave the best results. Extensive experimentation with the polymeric dimethoxy- and trimethoxysilanes, PS076.5 and PS076 respectively, gave similar results. Representative data for PS076.5 are shown in Table 2. Application from 0.5 wt% solutions in water produced the maximum IFSS and retention after exposure to 1 h boiling in water. 

It can precipitate as potassium hydrogen tartrate (KHT) or as calcium tartrate (CaT), the latter being practically insoluble in aqueous solutions. Their equilibrium solubility varies with temperature, pH, and alcohol content, while the presence of a few wine components, such as polysaccharides and mannoproteins, may hinder spontaneous nucleation even if the solution is supersaturated. From Figure 14 that shows the equilibrium tartaric acid-dissociated fractions versus pH and ethanol volumetric fraction (Berta, 1993 Usseglio-Tomasset and Bosia, 1978), it can be seen that in the typical pH range (3 4) of wines KHT is predominant. As temperature is reduced from 20 to 0°C, KHT solubility in water or in a 12% (v/v) hydro-alcoholic solution reduces from 5.11 to 2.45 kg/m3 or from 2.75 to 1.1 kg/m3, respectively (Berta, 1993). Each of these data also varies with pH and reaches a minimum at the pH value associated with the maximum concentration of the hydrogen tartrate anions. For the above-mentioned solutions, the solubility minimum shifts from pH 3.57 to pH 3.73 as the ethanol content increases from 0 to 12% (v/v) (Berta, 1993). 

Experimental results are presented for high pressure phase equilibria in the binary systems carbon dioxide - acetone and carbon dioxide - ethanol and the ternary system carbon dioxide - acetone - water at 313 and 333 K and pressures between 20 and 150 bar. A high pressure optical cell with external recirculation and sampling of all phases was used for the experimental measurements. The ternary system exhibits an extensive three-phase equilibrium region with an upper and lower critical solution pressure at both temperatures. A modified cubic equation of a state with a non-quadratic mixing rule was successfully used to model the experimental data. The phase equilibrium behavior of the system is favorable for extraction of acetone from dilute aqueous solutions using supercritical carbon dioxide. 

A major problem, that of reproducibility, soon became evident. Preparation of a class I blue , to which this discussion is restricted, typically involved incubation of an aqueous solution of CD -[Pt(NH3)2(H20)2](N03)2 (prepared from cisplatin and AgN03) with a pyrimidine-2,4-dione or a cyclic amide over a period of 3 - 5 days in air, 37 °C, with the pH kept constant (at 7) by repeated addition of NaOH. Various fractions of products were then obtained upon cooling the solution and/or after addition of ethanol. Consequently, these fractions differed in color (dark blue, light blue, green, purple), as did elemental analysis data. If the pH was not kept at 7 but rather allowed to drop, products were likewise different. In particular,... 

Di-jj-chloro-dichlorobis(ethylene)diplatinum(II) is customarily prepared by evaporating an aqueous solution of H[PtCl3(C2H4)] to dryness and then recrystallizing the dimer.1 However, this procedure has not been applied as a general synthesis of other related olefin complexes. The dimer has also been prepared, but with less success, by the reaction of Na2PtCl6 with boiling ethanol.2 The direct reaction of ethylene with platinum(IV) chloride also provides the dimer,3 but yield data are not available and presumably the method is unsatisfactory. 

It is unfortunate that there has been so little work devoted to quantitative measurements of cation-pseudobase equilibria in methanol and ethanol since these media have several advantages over water for the determination of the relative susceptibilities of heterocyclic cations to pseudobase formation. The enhanced stability of the pseudobase relative to the cation in alcohols compared to water is discussed earlier this phenomenon will permit the quantitative measurement of pseudobase formation in methanol (and especially ethanol) for many heterocyclic cations for which the equilibrium lies too far in favor of the cation in aqueous solution to allow a direct measurement of the equilibrium constant. Furthermore, the deprotonation of hydroxide pseudobases (Section V,B) and the occurrence of subsequent irreversible reactions (Sections V,C and D), which complicate measurements for pKR+ > 14 in aqueous solutions, are not problems in alcohol solutions. Data are now available for the preparation of buffer solutions in methanol over a wide range of acidities.309-312 An appropriate basicity function scale will be required for more basic solutions. The series of -(substituted phenyl)pyridinium cations (163) studied by Kavalek et al.i2 should be suitable for use as indicators in at least some of the basic region. The Hm and Jm basicity functions313 should not be assumed90 to apply to methoxide ion addition to heterocyclic cations because of the differently charged species involved in the indicators used to construct these scales. 

Aqueous solutions of these alcohols occur when sugar solutions are fermented and may be separated by distilling the mixtures. It is a common, economically valuable process for manufacturing potable liquors and for producing industrial alcohol from fermented molasses solutions or pulp mill wastes. One of the authors (A.Y.M.) reports that design and operation of these columns is hampered by lack of vapor-liquid equilibrium data, especially for making potable liquors, where small amounts of the alcohols other than ethanol greatly affect the flavor and, therefore, the products marketability. 

Reference Solution. Prepare an aqueous solution containing 0,2 mg/ml of each of ethanol, methanol, isopropyl alcohol, and propMiol, and inject 1 jiil on to the column. The retention data for these compounds are listed in Table 14,... 

Aqueous solutions of triorgano telluronium halides formed precipitates when mixed with aqueous solutions of copper(II) chloride zinc(II) chloride , gold(III) chloride ", mercury(II) halides " , and tin(II) chloride. Analytical data are only available for the mercury compounds. These data indicate that equimolar amounts of the telluronium halide and the mercury halide combine. The reactions can also be carried out in ethanol" . 

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