Butanol in water

Divide the saturated solution of n-butyl alcohol in water into three approximately equal parts. Treat these respectively with about 2-5 g. of sodium chloride, potassium carbonate and sodium hydroxide, and shake each until the soli have dissolved. Observe the effect of these compounds upon the solubility of n-butanol in water. These results illustrate the phenomenon of salting out of organic compounds, t.e., the decrease of solubility of organic compounds in water when the solution is saturated with an inorganic compound. The alcohol layer which separates is actually a saturated solution of water in n-butyl alcohol. 

Acute oral LD q data for nitro alcohols in mice are given in Table 1. Because of their low volatiHty, the nitro alcohols present no vapor inhalation ha2ard. They are nonirritating to the skin and, except for 2-nitro-1-butanol, are nonirritating when introduced as a 1 wt % aqueous solution in the eye of a rabbit. When 0.1 mL of 1 wt % commercial-grade 2-nitro-1-butanol in water is introduced into the eyes of rabbits, severe and permanent corneal scarring results. This anomalous behavior may be caused by the presence of a nitro-olefin impurity in the unpurifted commercial product. 

Fig. 3. Eleotrooapillary curves for various concentrations of butanol in water. (Taken from Bockris etal., 1963.)...

As a last example, we consider the binary phase diagram of water and 1-butanol (Figs. 6.16 and 6.17). There is a negative heat of mixing, HE, but a positive excess Gibbs energy of mixing, GE. The infinite dilution activity coefficient of 1-butanol in water is very... 

Fig. 9. Effect of solution pH on the redox behavior of an Ru02 aqueous solution interface. (— -), From work with an Ru02/Ti02 film [209]. The upper lines are for the Ru(IV)/Ru(VI) transition as obtained from voltammograms for pure RuOz (on Ti) in a range of borate (pH > 8) and phthalate (pH < 8) buffer solutions O and refer to the cathodic and anodic peak maxima respectively. (- -), Variation of the half-wave potential for benzaldehyde oxidation (O.lmoldm-3, scan rate = 1.5mVs 1) on pure Ru02 in buffered 10% f-butanol in water mixtures. The voltammograms outlined on the left and right for Ru02 in acid and base, respectively [207],...

Tetramethylsilane in DMSOdg and terf-butanol in water as internal references. Temperature coefficient, ppm to a higher field per degree. 

The asymmetry at the surface can affect the energy of different species in solution to different degrees. If, for example, we dissolve equal amounts of methanol and butanol in water, the concentration of butanol in the interphase will be higher. This comes about because the transfer of butanol from the bulk to the interphase decreases the total free energy of the system more than does the transfer of methanol. 

Typical non-ideal binaries forming two liquid phases is the n-butanol-water system at 1 atmospheric pressure. A solution with approximately 2 mole% n-butanol in water exists at equilibrium with another liquid phase with approximately 38 mole% n-butanol in water. The fugacity of n-butanol in both phases is about 0.48. A phase diagram of this binary is illustrated in Figure 1.16. The curves, which closely match the experimental data, are based on calculations using the NRTL equation for activity coefficients. 

The surface area model for solubility in water or any solvent can be further investigated by measuring the effect of temperature or added salt. Preliminary measurements indicate that some of the above models are not satisfactory. We find that the solubility of butanol in water decreases while the magnitude of surface tension of aqueous NaCl solution increases. These kinds of data are important for such systems as EOR (enhanced oil recovery). 

This type of normalization procedure works well for measurement of odor intensities. We have chosen the use of 270 parts-per-million of n-butanol in water as the internal standard for odor intensity evaluations. The current procedure is to... 

The sensory observations obtained for this detergent work were normalized by the internal standard method against 270 ppm butanol in water. Thus, odor intensities of 30 are moderate and intensities of 60 are strong. 

The trans — cis isomerization kinetics of bis(oxalato)diaquachromium(III) have now been measured in water ethanol and water butanol mixtures. An oxalate dissociative mechanism has been proposed, as the rates in H2O and D2O are identical. When alcohol is added to water, there is a marked decrease in i som Plots of ln(/ 3o ,) vs. ln[H20] have breaks at positions corresponding to boundary values for water alcohol ratios determined for other systems (---O.OS mole fraction of t-butanol). In water, 10 s" = 7.96 (30.0), 9.33(31.0), 11.2(35.0),... 

The VLB diagram for the butanol/water system and the high values of y for both butanol in water and water in butanol show that the fractionating approach to the azeotrope is very easy from both directions so that the columns required for the continuous separation need only a few plates. 

The alcohol concentration in the sample is calculated with the assistance of standard samples containing ethanol in water at known concentrations and the amount of the internal standard added to the samples. A volume of 0.5 ml of the specimen to be analyzed is pipetted into a vessel 0.1 ml of the internal standard (a 0.2% w/v solution of ferf-butanol in water) is added the vessels are sealed with a rubber septum and the covers are secured with aluminum caps to compensate for the eventuality of an excess pressure buildup. For standard samples, instead of the specimen, 0.5 ml of a known ethanol concentration solution is added. Finally, the vessels are placed into the turntable of the headspace analyzer, which is thermo-statted at 60°C. ... 

For example, the addition of 1 pi quantities of pure n-butyl alcohol to 150 pi of water placed in the cell produces heat effects shown in Figure 7. The heats of mixing decrease to a value close to zero as the saturation concentration of n-butanol in water (7 percent by weight at 25 C) is approached. Additions of 1 percent n-butanol solutions to water produce no measurable heat of mixing effects and can, therefore, be ignored when the heat of n-butanol adsorption is measured from its 1 percent solution in water is measured on various hydrophobic adsorbents. 

Figure 7. Heats of mixing of n-butanol in water produced by direct injection of 1 pi quantities of the pure alcohol into 150 pi of water in the adsorption cell. Determinations under static conditions at 25°C.

In earlier work on thermal perturbation spectra of phenolic compounds it was shown that -butanol in water gives a maximum in 1 82901 at about 0.1 mole fraction (35% v/v). MPD does the same at about 0.05 mole fraction. When glycerol is the major solvent, is constant over the range studied, 0 to 50% (v/v) r-butanol. The effect of f-butanol on in H2O is easily ascribed to solvent structure effects, in accord with the viscosity data, except that the maximum in viscosity is at 0.2 mole fraction, /-butanol in glycerol does not produce a viscosity increase, but rather a negative deviation at all compositions, that is, a net disruption in structure. But within that disruption there may be a formation of a new structure. 

The reaction of phenol with terf-butanol in water at 250,275, and 300°C to produce 2-tert-butylphenol and 4-tert-butylphenol has been reported by Chandler et al. (Fig. 9.33). The mole fraction of product yields are shown as a function of time at each temperature in Figs. 9.34-9.36. When the products were subjected to NCW at 275°C, phenol was produced, indicating that the reaction is reversible. Small quantities (5%) of 2,4-di- fert-butylphenol are also formed. The reaction kinetics were described using a simple reaction network involving two reversible, first-order reactions (Fig. 9.37). 

It has already been mentioned that the K, in NCW is several orders of magnitude greater than in water at room temperature. Thus, as shown previously, acid and base catalysis can be facilitated without the use of additional acid. Certainly CO2 reacts with water to form carbonic acid and, as a consequence, the concentration of hydronium ion in NCW can be increased by enriching the medium with CO2. From an environmental point of view this procedure wiU not only facilitate specific acid-catalyzed reactions but will not require neutralization of the acid after the reaction is complete. A simple cooling and depressurization will eliminate the CO2 and phase separates the product(s) of reaction. Thus, Aleman et al. have reported that the conversion of mesitoic acid to mesitylene over a period of 120 min at 250°C increased from 50 to 80% in the presence of 10 bar (rt) of CO2. Hunter and Savage reported the dehydration of cyclohexanol in water at 250 and 275°C and the reaction of p-cresol with tert-butanol in water at 275°C in the absence and presence of CO2. Their results indicated that in the presence of CO2 the rate of dehydration of the cyclohexanol increased by more than a factor of 2 and the rate of formation of 2-tert-butyl-4-methylphenol increased 40-120%. Modest increases in rate were reported for the hydration of cyclohexene to cyclohexanol. 

FIGURE 7.14 Correlation between a relative decrease in the surface free energy of naphthalene single crystals and a relative decrease in the strength of polycrystalline naphthalene specimens in (1) benzene, (2) heptane, (3) methylene chloride, (4) chloroform, (5) carbon tetrachloride, (6) methanol, (7) ethanol, (8) propanol, (9) n-butanol, (10) r-butanol, and (11) 0.2 M solution of n-butanol in water. (Data from Pertsov, N.V. and Rehbinder, P.A., Doklady AN SSSR, 123,1068,1958 Skvortsov, A.G. et al., Doklady AN SSSR, 193,76,1970 Pertsov, N.V. et al., Doklady AN SSSR, 179, 633, 1968.)... 

Reaction Esterification of propionic acid and 1 -butanol in water/w-decane. 

For each of the following questions, assume that all measurements are made in 10-cm polarimeter sample containers. (a) A 10-mL solution of 0.4 g of optically active 2-butanol in water displays an optical rotation of —0.56°. What is its specific rotation (b) The specific rotation of sucrose (common sugar) is +66.4. What would be the observed optical rotation of such a solution containing 3 g of sucrose (c) A solution of pure (5)-2-bromobutane in ethanol is found to have an observed a = 57.3°. If [a] for (S)-2-bromobutane is 23.1, what is the concentration of the solution ... 

Although S and 6 readily formed co-crystals from a number of different solvents such as 50% tert-butanol in water, great difficulty was encountered obtaining crystals of suitable quality for a single crystal X-ray structure determination of the monomer. There were two reasons for this difficulty. The crystals were extremely small and polymerization appeared to be occurring at room temperature, which decreased the crystal quality. Thermal annealing at 120 °C for 12 h resulted in complete polymerization and a single crystal suitable for X-ray structure determination could be found (Scheme 5.4). 

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