Chloroform, vapor pressure

Figure 8 Acetone-chloroform vapor pressure diagram at 35.2°C. (Data from Example 1.)...

FIGURE 8.40 A graphical illustration of the variation in the vapor pressures of (a) a mixture of ethanol and benzene and (b> a mixture of acetone and chloroform. Note that the mixture in part (ai shows a vapor-pressure maximum and therefore displays a positive deviation front Raoult s law. The one in part (hi shows a minimum and hence displays a negative deviation from Raoult s law. 

Trichloromethyl chloroformate is useful in synthesis as a substitute for phosgene, which, owing to its high volatility and toxicity, presents a severe hazard in the laboratory. Although trichloromethyl chloroformate is toxic, it is a dense and less volatile liquid, b.p. 128°, d l 1.65, having a vapor pressure of only 10 mm. at 20°. Consequently it is more easily handled in a safe manner than phosgene. 

The chlorodifluorophosphine prepared in this manner has a vapor pressure of 312.0 mm. at —63.6° (chloroform slush). The infrared spectrum of the vapor shows absorptions at the following frequencies 864.5 (s), 853.5 (vs), 543.7 (s), and 412.5 (m) cm.-1 in the 4000 to 200 cm.-1 region. Disproportionation of the liquid is fairly rapid contact of the vapor with mercury also appears to hasten disproportionation. Thus chlorodifluorophosphine is best prepared just prior to use. It may be stored at —196°. 

What is the vapor pressure of a solution made by mixing 80.0 g of chloroform, CHCl3, in 800.0 g of carbon tetrachloride, CCl4 The vapor pressure of chloroform is 197 torr, and the vapor pressure of carbon tetrachloride is 114 torr (all vapor pressures are determined at 25°C). 

A solution of chloroform, CHC13, in carbon tetrachloride, CC14, is nearly ideal. The vapor pressure of chloroform is 170 mm Hg at 20°C, and the vapor pressure of carbon tetrachloride is 87 mm Hg at this temperature. What is the mole fraction of carbon tetrachloride in the vapor over an equimolar solution of these two liquids ... 

We shall use the data of Mato et al. [2] for the vapor pressure and vapor composition of mixtures of methyl tert-butyl ether [1] and chloroform (2) at 313.15 K to illustrate the procedures used to calculate as a function of composition. These data are plotted in Figure 17.3. 

Figure 17.3. Data for vapor pressure and composition of solutions of methyl rert-butyl ether Pi and chloroform p2 at 313.15 K. Data from Ref. 2.

Based upon a vapor pressure of 159 mm Hg at 20 °C, chloroform is expected to exist almost entirely in the vapor phase in the atmosphere (Boublik et al. 1984 Eisenreich et al. 1981). Large amounts of chloroform in the atmosphere may be removed by wet deposition since chloroform has significant solubility in water. This is confirmed by its detection in rainwater (Kawamura and Kaplan 1983). Most of the chloroform removed in precipitation, however, is likely to reenter the atmosphere by volatilization. Trace amounts of... 

Passino-Reader, D.R., Hickey, J.P., and Ogilvie, L.M. Toxicity to Daphnia pulexmA QSAR predictions for polycyclic hydrocarbons representative of Great Lakes contaminants. Bull. Environ. Contam. Toxicol, 59(5) 834-840, 1997. Pathare, S., Bhethanabotla, V.R., and Campbell, S.W. Total vapor-pressure measurements for 2-ethoxyethanol with carbon tetrachloride, chloroform, and dichloromethane at 303.15 K, J. Chem. Eng. Data, 49(3) 510-513, 2004. 

Resa, J.M., Gonzalez, C., de Eandaluce, S.O.,andLanz,J. Vapor-liquid equilibrium of binary mixtures containing diethylamine + diisopropylamine, diethylamine + dipropylamine, and chloroform + diisopropylamine at 101.3 kPa, and vapor pressures of dipropylamine, J. Chem. Eng. Data, 45(5) 867-871, 2000. 

Xu, R., Leonard J., and Bui, V.T. Vapor pressure for mixtures of methylene ester oligomers with /rdioxane and chloroform, /. 

Colorless gas pungent suffocating odor density 2.975 g/L fumes in moist air liquefies at -101°C sohdifies at -126.8° vapor pressure at -128°C is 57.8 torr critical temperature -12.2°C critical pressure 49.15 atm critical volume 115 cm3/mol soluble in water with partial hydrolysis solubdity in water at 0°C 332 g/lOOg also soluble in benzene, toluene, hexane, chloroform and methylene chloride soluble in anhydrous concentrated sulfuric acid. 

White orthogonal crystal density 1.77 g/cm sublimes at ordinary temperatures vapor pressure 1 torr at 48°C decomposes at 130°C insoluble in water and alcohols soluble in ether, chloroform and methylene chloride. 

Colorless fuming liquid suffocating odor density 1.52 g/mL freezes at -68.9°C boils at 57.7°C vapor pressure 235 torr at 25°C critical temperature 235°C critical pressure 35.45 atm critical volume 326 cm /mol decomposes in water forming silicic acid and HCl soluble in benzene, toluence, chloroform, and ether. 

Water freezes to ice at 0°C expands by about 10% on freezing boils at 100°C vapor pressure at 0°, 20°, 50°, and 100°C are 4.6, 17.5, 92.5, and 760 torr, respectively dielectric constant 80.2 at 20°C and 76.6 at 30°C dipole moment in benzene at 25°C 1.76 critical temperature 373.99°C critical pressure 217.8 atm critical density 0.322 g/cm viscosity 0.01002 poise at 20°C surface tension 73 dynes/cm at 20°C dissolves ionic substances miscible with mineral acids, alkalies low molecular weight alcohols, aldehydes and ketones forms an azeotrope with several solvents immiscible with nonpolar solvents such as carbon tetrachloride, hexane, chloroform, benzene, toluene, and carbon disulfide. 

In the specific case of the tailed sapphyrin carboxylates 5 and 6, for which evidence of self-assembly was noted in the solid state (vide supra), H NMR spectroscopic studies carried out in 4-methanol, d-chloroform, and mixtures of the two solvents showed strong line broadening, and upfield shifts of the methylene tail peaks. Such findings are, of course, fully consistent with the proposed dimerization. Further, dilution experiments performed over a concentration range of 50 to 5 mM in these solvents showed little change in the spectra, indicating that the dimeric form prevails under these conditions, even in highly polar solvents. In the case of 6, the actual dimeric stoichiometry was confirmed by vapor pressure osmometry (VPO) measurements carried out in 1,2-dichloroethane. 

The Group 6 compounds glucose and glycine were not tested at the small-scale level because previous work suggested that they would not be soluble in supercritical fluid CO2. Additionally, chloroform was not tested at this level because it is undoubtedly extractable but would pose significant trapping problems because of its relatively high vapor pressure. 

VOLATILE. Having a low boiling or subliming temperature at ordinary pressure in other words, having a high vapor pressure, as ether, camphor, naphthalene, iodine, chloroform, benzene or methyl chloride. 

The Extrelut cleanup method is suitable for most foodstuffs, such as cheese, yogurt, and other samples that tend to form emulsions during extraction. The prepacked or refilled Extrelut column in a plastic tube consists of a wide-pore kieselgel column. A sample is homogenized in 0.5 N sulfuric acid, diluted with water, and applied onto the Extrelut column for at least 15 min. The absorbed preservatives are eluted with a chloroform - isopropanol (9 1) mixture, and the elu-ate is collected and evaporated carefully nearly to dryness. The last few milliliters of solvent are removed with a gentle flow of nitrogen to prevent substantial losses of BA and SA, which have relatively high vapor pressures. The residue is transferred with methanol into a 10-ml volumetric flask and diluted to volume with methanol. To speed up the dissolution, the use of an ultrasonic bath is recommended. The filtered extract is analyzed on a /zBondaPak Cl8 column, with a... 

The industrial solvents chloroform, CHCI3, and dichlo-romethane, CH2CI2, are prepared commercially by reaction of methane with chlorine, followed by fractional distillation of the product mixture. At 25°C, the vapor pressure of CHCI3 is 205 mm Hg and the vapor pressure of CH2CI2 is 415 mm Hg. What is the vapor pressure (in mm Hg) at 25°C of a mixture of 15.0 g of CHCI3 and 37.5 g of CH2C12 ... 

Vapor pressure osmometric and spectroscopic studies on the molecular association and dissociation of (Z)-vinyl(bromo)-A3-iodane 130 in chloroform solution indicate the equilibrium formation of the dimer 131 as well as the iodonium ion 129, which is stabilized by the coordination of the solvent chloroform via the hypervalent interaction between the positively charged iodine and a chlorine atom [212]. 

The sample treatment is executed as follows The sample is located inside the chamber. The SFM scanner is retracted by about 8 mm from the sample. Then the chamber is closed by the lid. In order to anneal the sample successfully, we perform the treatment in a hermetically sealed reactor chamber. The sample is exposed to chloroform vapor while a voltage is applied across the electrodes on the glass substrate. The gas flow rate through the system is controlled by mass flow controllers and additionally checked by a flow meter installed at the outlet of the chamber. After a certain annealing time, the solvent is removed with a flow of pure argon while the voltage is still applied in order to quench the structure in the presence of the electric field. Subsequently the lid is opened, the voltage is switched off, and the SFM scanner is moved towards the sample. This procedure is repeated several times. The accomplishable position stability as a key performance feature of the quasi in situ SFM amounts to almost the same value as reported in [32] (low pressure plasma treatments). The increase in lateral drift is only about 23 nm per process step. The... 

The increase of the solvent concentration in SB41 films on raising the partial pressure of chloroform vapor, and the related loss of long-range order, can be explained in terms of the so-called dilution approximation for the bulk block copolymer phases [167, 168], The above results clearly demonstrate the high sensitivity of the polymer-polymer interactions towards solvent content. Therefore, the microphase-separated structures in swollen block copolymer films can be used as a qualitative measure of the degree of swelling of the films [49, 166],... 

Fig. 19 Polymer volume fraction (j) = h( iy //jsw in swollen films of two PS-h-PB diblock copolymers (.S //47 (circles) and SB10 (squares)) that have been equilibrated at p/po 50% of the partial chloroform (non-selective solvent) vapor pressure [114], and of SV films (triangles) equilibrated under p/po = 80% of toluene (selective solvent) [119] versus the number of layers (film thickness normalized by the respective structure dimension in bulk)...

Fig. 22 Simulated images (upper panel) and SFM phase images (300 x 300 nm) (lower panel) presenting classical topological defect configurations in lying cylinders (a, e) cyl-dislocation (b, f) m-dislocation (c, g) +1/2 cyl-disclination and (d, h) +1/2 m-disclination. SB films were annealed under 70% of the saturated vapor pressure of chloroform. Reprinted from [36], with permission. Copyright 2008 American Chemical Society...

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