Carbon tetrachloride/water systems

Fig. 5.3. Chromatograms of components of a test sample in carbon tetrachloride-water system (A) before and (B) after injection of sodium bisulphite into the system. For peaks 1-8, see text. Reprinted with permission from ref. 16.

A very efficient method for the oxidation of secondary alcohols to ketones makes use of sodium bromate in the presence of ruthenium dioxide. Quantitative yields are obtained in 15 min at 25°C. Pulsed irradiation, with a 20% duty cycle, was used in addition to stirring. It appears that the sonochemical rate increase is due to two factors the acceleration of the oxidation of ruthenium dioxide to the actual reactive species ruthenium tetroxide, and the very efficient ultrasonic emulsification of the biphasic carbon tetrachloride-water system. 

F can also be separated by solvent extraction. Faure et al. (223)(224) used solvent extraction with disphenyldichiorosilane in isopropyl ether for the determination of oxygen in molybdenum and lead. The separation of F by solvent extraction using triphenyl antimony (V) derivatives is described by Chermette et al. (225)(226). It is shown that, if fluoride is extracted with an excess of reagent, the extracted salt is triphenyl-antimonyhydroxyfluoride if the pH is not too low. The partition constants of this compound in benzene-water and carbon tetrachloride-water systems are high. The kinetics of the fluoride exchange reaction ... 

Besides ruthenium tetroxide, other ruthenium salts, such as ruthenium trichloride hydrate, may be used for oxidation of carbon-carbon double bonds. Addition of acetonitrile as a cosolvent to the carbon tetrachloride-water biphase system markedly improves the effectiveness and reliability of ruthenium-catalyzed oxidations. For example, RuCl3 H20 in conjunction with NaI04 in acetonitrile-CCl4-H20 oxidizes (Ej-S-decene to pentanoic acid in 88% yield. Ruthenium salts may also be employed for oxidations of primary alcohols to carboxylic acids, secondary alcohols to ketones, and 1,2-diols to carboxylic acids under mild conditions at room temperature, as exemplified below. However, in the absence of such readily oxidized functional groups, even aromatic rings are oxidized. 

Let us illustrate the meaning of partition coefficients with the simple extraction system carbon tetrachloride/water. Using ammonia or iodine as the solute, the partition coefficient Kp at 25°C is 0.0042 and 55, respectively [62]. With polar ammonia as the solute, this would move primarily to the water phase on extraction, hence the low Kp. With nonpolar iodine, the higher concentration would accumulate in the nonpolar carbon tetrachloride phase. 

If the solvent is one of those listed in the third section (set "C ) of Table 1 9, the appropriate equation (from Eqs. 1-27 to -35) is selected irrespective of the solute class. Three equations are available for the instances when Ksw is from the carbon tetrachloride/water or chloro-form/water systems 1-9, -20, and -36 for the former and 1-13, -24, and -37 for the latter. Footnote a of Table 1-8 explains how the correct equation is selected based upon considerations of solute class. 

FIGURE 2.12 The interfacial adsorption of l,10-phenanthroline(phen) complexes in carbon tetrachloride/water and chloroform/water systems. 

It is often desirable to separate both phospholipids and neutral lipids on the same silica gel plate. This can be done using the double development procedure of Johnston (94) or any one of various minor modifications. In this technique, phospholipids are first separated in chloroform-methanol-water (65 25 4). After the plate is dried, it is developed in the same direction in the second solvent consisting of hexane-diethyl ether (4 1). For detailed procedures of this double development technique, see Fried and Shapiro (95). Aloisi et al. (95a) compared a total of 24 solvent systems for the unidimensional separation of neutral lipids and phospholipids on preadsorbent silica gel plates. They found that the best overall separation was achieved by consecutive development with chloroform-methanol-water (65 24 4), chloroform-hexane (3 1), and carbon tetrachloride the system of choice for quantification by scanning densitometry was hexane-diethyl ether-formic acid (80 20 2). 

We illustrate these results by examining the system carbon tetrachloride-water. The solubility of CCI4 in water is listed in Table 6.3 as 0.8 g/1 = 800 ppm. The solubility of water in carbon tetrachloride is almost 10 times lower at 84 ppm. Converting to mole fraction, we obtain... 

Van Aartsen, J. J. Korvezee, A. E. The ternary system carbon tetrachloride - water - tributyl phosphate (TBP). Red. Trav. Chim. Pays-Bas 1964, 83, 752-763. 

If an ethyl ether fire occurs, carbon dioxide, carbon tetrachloride, and dry chemical fire extinguishers meeting National Eire Prevention Association Code 1 and 2 requirements may be used successhiUy (23). Water may also be effectively appHed (see Plant safety). Hose streams played into open tanks of burning ethyl ether serve only to scatter the Hquid and spread the fire. However, ether fires may be extinguished by a high pressure water spray that cools the burning surface and smothers the fire. Automatic sprinklers and deluge systems are also effective. 

Decreases with increasing wettability of liquid on plate surface. Kerosene, hexane, carbon tetrachloride, butyl alcohol, glycerine-water mixtures all wet the test plates better than pure water. The critical tray stability data of Hunt et al., [33] is given in Table 8-21 for air-water, and hence the velocities for other systems that wet the tray better than water should be somewhat lower than those tabulated. The data of Zenz [78] are somewhat higher than these tabulated values by 10-60%. 

Tetrapropylporphycene 6 is brominated on treatment with bromine in a two-phase system of carbon tetrachloride and water at the four /(-pyrrolic positions26 to yield the tetrabromo derivative 7. 

Carbon tetrachloride-hydrogen sulfide-water ternary system, 49, 51, 52 Carboniuin ion polymerization, 158 Carboxylic groups initiator, 174 Catalyst clathrates equilibrium, 35 Cell partition function, in calculation of thermodynamic quantities of clathrates, 26... 

Comparing equations 13.8 and 13.9, it is seen that the adiabatic saturation temperature i > equal to the wet-bulb temperature when s = h/hDpA. This is the case for most water vapour systems and accurately so when Jf = 0.047. The ratio (h/hopAs) = b is sometimes known as the psychrometric ratio and, as indicated, b is approximately unity for the air-water system. For most systems involving air and an organic liquid, b = 1.3 - 2.5 and the wet-bulb temperature is higher than the adiabatic saturation temperature. This was confirmed in 1932 by SHERWOOD and COMINGS 2 who worked with water, ethanol, n-propanol, n-butanol, benzene, toluene, carbon tetrachloride, and n-propyl acetate, and found that the wet-bulb temperature was always higher than the adiabatic saturation temperature except in the case of water. 

G. N. Lewis proposed the term escaping tendency to give a strong kinetic-molecular flavor to the concept of the chemical potential. Let us consider two solutions of iodine, in water and carbon tetrachloride, which have reached equilibrium with each other at a flxed pressure and temperature (Fig. 9.2). In this system at equilibrium, let us carry out a transfer of an inflnitesimal quantity of iodine from the water phase to the carbon tetrachloride phase. On the basis of Equation (9.17), we can say that... 

In this closed system, any loss of iodine from the water phase is accompanied by an equivalent gain in the carbon tetrachloride thus. 

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