Ethanol critical density

Colorless gas (or fuming hquid) density 5.14 g/L hquefies at 12.6°C solidifies at -107°C vapor pressure 470 torr at 0°C critical temperature 182°C critical pressure 38.2 atm critical molar volume 239 cm /mol reacts with water and ethanol soluble in carbon tetrachloride. 

Colorless and odorless gas refractive index 1.000036 at 0°C and 1 atm density of the gas at 0°C and 1 atm 0.1785 g/L density of hquid hehum at its boihng point 0.16 g/mL liquefies at -268.93°C sohdifies at -272.2°C (at 26 atm) to a crystalline, transparent and almost invisible sobd having a sharp melting point cannot be solidified at the atmospheric pressure except by lowering temperatures critical temperature -267.96°C critical pressure 2.24 atm critical volume 57cm3/mol very slightly soluble in water solubility in water 0.0285 mg/L (calculated) at 25°C or 0.174 mL/L at NTP insoluble in ethanol. 

Colorless volatile liquid diamagnetic flammable burns with a bright luminous flame density 1.319 g/mL freezes at -25°C boils at 43°C vapor pressure 320.6 torr at 20°C vapor density 5.89 (air=l) critical temperature about 200°C critical pressure 30 atm practically insoluble in water, 180 mg/L at 10°C miscible with most organic solvents including ethanol, acetone, and benzene soluble in nitric acid and aqua regia. 

Colorless, odorless gas density 6.41 g/L about five times heavier than air liquefies at -50.7°C (triple point) density of liquid 1.88 g/mL at -50.7°C sublimes at -63.8°C critical temperature 45.54°C critical pressure 37.13 atm critical volume 199 cm /mol slightly soluble in water soluble in ethanol. 

Yellow monoclinic crystals hygroscopic density 3.68 g/cm melts at 216°C vaporizes at 239.4°C critical temperature 494°C critical volume 402 cm /mol can be sublimed without decomposition in chlorine atmosphere reacts with water soluble in ethanol, ether and carbon tetrachloride. 

Colorless or yellow liquid penetrating acid odor absorbs moisture from air produces dense white fumes density 1.73 g/mL freezes at -25°C boils at 136.5°C critical temperature 464.8°C critical pressure 46.6 atm critical volume 339 cm /mol reacts with water forming Ti02 and HCl soluble in ethanol... 

The immunoreplica technique (14) is used when it is necessary to detect antigenic sites on the plasma membrane of cultured cells. The cells are cultured on coverslips, and are fixed as described above depending on the antibody in question, and immunolabeled in situ as described in Section 3.1.1.2., steps 3-9. After immunolabeling (Section 3.1.1.2., step 9), they are further fixed with 1% osmium tetroxide and are dehydrated in a graded series of ethanol (70, 90, 100%), critically point-dried, and replicated with a layer of carbon and platinum, The replicas are cleaned with sodium hypochlorite and chronic acid before examination with the transmission electron microscope. Large areas of the replicated plasma membrane remain intact for observation. Colloidal gold probes are probably the only probes of sufficient density that can be detected on these surfaces. 

Determination of pure component parameters. In order to use the EOS to model real substances one needs to obtain pure component below its critical point, a technique suggested by Joffe et al. (18) was used. This involves the matching of chemical potentials of each component in the liquid and the vapour phases at the vapour pressure of the substance. Also, the actual and predicted saturated liquid densities were matched. The set of equations so obtained was solved by the use of a standard Newton s method to yield the pure component parameters. Values of exl and v for ethanol and water at several temperatures are shown in Table 1. In this calculation vH and z were set to 9.75 x 10"6 m3 mole"1 and 10, respectively (1 ). The capability of the lattice EOS to fit pure component VLE was found to be quite insensitive to variations in z (6[Pg.90]

The critical point refers to the certain combination of temperature and pressure at which the liquid density is equal to the vapor density. At its critical point, liquid will become vapor and is easily removed. We cannot directly remove water using its critical point because the temperature and pressure of the critical point (374°C and 22 MPa) are too high and may damage the specimen. Alternatively, we can replace water with a transitional fluid that has a critical point with lower temperature and pressure. Liquid CO2 or Freon is often used as the transitional fluid. The critical point for liquid CO2 is 31.1 °C and 7.4 MPa. The common procedure is described as follows. First, water content in a specimen is removed by dehydration with an ethanol series (30, 50, 75 and 100%). Then, the dehydrated specimen is transferred into an ethanol-filled and cooled chamber in the critical-point drying apparatus. The transitional fluid is introduced until it completely displaces ethanol in the chamber. The chamber is gradually heated and pressurized to reach the critical point of the transitional fluid. After reaching the critical point, the transitional fluid vaporizes, and this vapor is slowly released from the chamber until atmospheric pressure is reached. Then, we can retrieve the intact, dry specimen from the chamber. 

Extreme cases of non-selectivity are encountered at the maximum and minimum densities. At maximum densities, the supercritical fluid has maximum solvent power so usually everything that is soluble at the various discrete lower densities is soluble at the maximum density - i.e., there is no selectivity if just the highest density is used in the extraction scheme. At that point, a different selectivity can be superimposed on the highest-density supercritical fluid by adding additional components, called modifiers, to the bulk fluid to form solvent mixtures. Typical modifiers are methanol, ethanol, methoxy ethanol, and methylene chloride. With carbon dioxide, the onset of noticeable solvent power occurs at about 0.1 g/mL this is the point at which the carbon dioxide makes a transition from ideal-gas behaviour (PVT equations) to critical-region behaviour where the density is an even more sensitive function of pressure (compared to ideal-gas behaviour). The result is that liquid-like, but selective, solvation occurs for carbon dioxide over the density range of about 0.1... 

Table 11.1 gives i and r for water at T = 273 K and 298 K as a function of S. As expected, we see that as 5 increases both i and r decrease. Table 11.2 contains surface tension and density data for five organic molecules, and values of i and r for these five substances at T = 298 K are given in Table 11.3. The critical radius r depends on the product ct J. For the five organic liquids a < awater but v > V Water- The organic surface tensions are about one-third that of water, and their molecular volumes range from 3 to 6 times that of water. The product ai i for ethanol is approximately the same as that of water, and consequently we see that the r values for the two species are virtually identical. Since i involves an additional factor of vi, even though the r values coincide for ethanol and water, the critical numbers i differ appreciably because of the large size of the ethanol molecule.

The International Critical Tables (Vol. V, p. 70) lists diffusivities for ethanol in water solution at 10°C., up to a concentration of 3.75 gm. mole ethanol/liter. The concentrations were converted to mole fractions using density data from Chemical Engineers ... 

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