Density tetrachloromethane

FIGURE 5.20 Variation in the densities of water and tetrachloromethane with tem )erature. Note that ire is less dense than liquid water at its freezing point and that water has its maximum density at 4°C. 

BP, BLYP, EDFl and B3LYP density functional models all lead to significant improvements over both Hartree-Fock and local density models, at least in terms of mean absolute deviations. While most reactions are better described, there are exceptions. Most notable among these is the bond separation reaction for tetrachloromethane. All four models show a highly exothermic reaction in contrast with both G3 and experimental results which show a nearly thermoneutral reaction. Similar, but somewhat smaller, effects are seen for isobutane and trimethylamine. As was the case with Hartree-Fock calculations. 

Weight losses measured during the transformation indicated that the two phases differed in their chemical composition. Assuming a MoS2 —> MoNx reaction, the x values were close to 1.2 and 1.0 for L-MoN and H-MoN respectively. Analysis of nitrogen and sulphur were again performed in a LECO analyser. N was determined as before, while S was detected as S02 by an infrared method. The results are reported in Table 13.9 as well as the density values measured in tetrachloromethane. 

Synonyms tetrachloromethane, tetrachlorocarbon Formula CC14 MW 153.81 CAS [56-23-5] used as a solvent colorless liquid with characteristic odor boils at 76.7°C freezes at -23°C vapor pressure 89.5 torr at 20°C density 1.59 g/mL at 20°C shghtly soluble in water ( 800 mg/L) miscible with organic solvents. 

The density, d, of a solvent depends on both the temperature and the pressure and its value at ambient conditions is an important characteristic. Most solvents at 25°C and 0.1 MPa have densities between those of w-pentane (0.62319 g cm-3) and of tetrachloromethane... 

In contrast to closo-carboranes (e.g. CBuHn, l,2-C2BioHi2, ) where electrophilic substitution occurs predominantly at the most electronegative boron atoms which are opposite to the carbon vertices, the SBnHn molecule is sensitive to reaction conditions and affords either B(7) or B(12) derivatives or their mixture. Halogenation affords at lower temperatures first the 7-X-derivatives whereas at reflux in low boiling medium (benzene, bromine, tetrachloromethane) the 12-X-compounds 2, 3 and 4 are the main products (see scheme). The absence of a direct electrophilic halogenation in the B(12) position under mild conditions seems to deny a high electron density at this end of the SBnHn molecule. 

Carbon tetrachloride, or tetrachloromethane, is a nonflammable, noncorrosive, colorle.ss liquid with a molecular weight or 153>84, a specific gravity of 1.58 (25 C), a boiling point of 76.76 C, a freezing point of -22.8 C, a vapor pressure of 89.5 mm 20 C, a vapor density of 5.6 water solubility of 0.28 g/kg at 25 C, a miscibility with alcohol, benzene, chloroform, ether, carbon disulfide, petroleum ether, and oils and is generally inert but can be decomposed in water at high temperatures (10-12), The odor threshold for CCljj has been reported at 60-70 ppm (13), at 21-100 ppm (liJ.), at approximately 50 ppm ( 1 ) and at a threshold of detection of 79 ppm with a strong odor at 176 ppm (10). 

Density measurements. Polymer densities were measured using the neutral buoyancy method using a pyconometer (75). The neutral buoyancy medium was a mixture of tetrachloromethane and hexane. 

The partial molar quantities of mixing were determined for normal and branched alkanes (O5 — Cio), cyclohexane, benzene and tetrachloromethane in polyisobutylene [57]. Partial molar enthalpies of mixing were measured for normal alkenes in low and high density polyethylene, polypropylene, polybutene-1, polystyrene, poly(methyl acrylate), poly(vinyl chloride), polyCN-isopropyl-acrylamide), ethylene-vinyl acetate copolymer, ethylene-carbon oxide copolymer [88] normal, branched and cyclic alkanes, benzene, n-butylbenzene, ois- and ra s-decalin, tetraline and naphthalene in polystyrene at 183, 193 and 203°C [60] these solutes in poly (methyl acrylate) [57] n-nonane, n-dodecane and benzene in polystyrene in the range 104.8 — 165.1 C [71] O7—C, C12 normal alkanes and aromatic hydrocarbons in polystyrene at an average temperature of 204.9°C [72], C7—Cg normal alkanes in poly(ethylene oxide) at an average temperature of 66.5 "C [72] normal alkanes in ethylene oxide—propylene oxide block copolymers (Pluronics L 72, L 64 and F 68) at the same average temperature [72]. 

The overall density d of the yarns was determined in a density gradient column containing a mixture of tetrachloromethane/n-heptane at 23.0°C. The crystalline density, d, was obtained from WAXS combined with curve fitting, as discussed in Ref. 1. In practice, the value of the 1 — varies only slightly in drawn yarns, namely, between 0.60 and 0.67 in this series. 

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