Physical Property Constants

Constants and Conversion Factors Basic and Supplementary Units Derived Units and Quantities Physical Constants Properties oe Water Periodic Table of the Elements... 

Physical Properties. Benzene, C H, toluene, C Hj-CH, and petrol (a mixture of aliphatic hydrocarbons, e.g., pentane, hexane, etc.) are colourless liquids, insoluble in and lighter than water. Benzene and toluene, which have similar odours, are not readily distinguishable chemically, and their physical constants should therefore be carefully noted benzene, m.p. 5 (solidifies when a few ml. in a dry test-tube are chilled in ice-water), b.p. 8i toluene, m.p. —93°, b.p. 110°. Petroleum has a characteristic odour. 

The physical constants of furfuryl alcohol are Hsted in Table 1. When exposed to heat, acid or air the density and refractive index of furfuryl alcohol changes owing to chemical reaction (51), and the rate of change in these properties is a function of temperature and time of exposure. 

In addition to H2, D2, and molecular tritium [100028-17-8] the following isotopic mixtures exist HD [13983-20-5] HT [14885-60-0] and DT [14885-61-1]. Table 5 Hsts the vapor pressures of normal H2, D2, and T2 at the respective boiling points and triple points. As the molecular weight of the isotope increases, the triple point and boiling point temperatures also increase. Other physical constants also differ for the heavy isotopes. A 98% ortho—25/q deuterium mixture (the low temperature form) has the following critical properties = 1.650 MPa(16.28 atm), = 38.26 K, 17 = 60.3 cm/mol3... 

Physical Properties. An overview of the metallurgy (qv) and soUd-state physics of the rare earths is available (6). The rare earths form aUoys with most metals. They can be present interstitiaUy, in soUd solutions, or as intermetaUic compounds in a second phase. Alloying with other elements can make the rare earths either pyrophoric or corrosion resistant. It is extremely important, when determining physical constants, that the materials are very pure and weU characteri2ed. AU impurity levels in the sample should be known. Some properties of the lanthanides are Usted in Table 3. 

Physical Properties. Almost all Hquid diacyl peroxides (20) and concentrated solutions of the soHd compounds are unstable to normal ambient temperature storage many must be stored well below 0°C. Most of the soHd compounds are stable at ca 20°C but many are shock-sensitive (187). Other physical constants and properties have been reviewed (187,188). The melting poiats and refractive iadexes of some acyl peroxides are Hsted ia Tables 10-12. 

Physical and Chemical Properties. Tables 5, 6, and 7 bst some of the physical and chemical properties of phthabc acid and its anhydride. Table 5. Physical Constants of Phthalic Acid and Phthalic Anhydride... 

Table 24. Physical Constants and Properties of Isophthalic Acid...

Physica.1 Properties. Carbonyl sulfide [463-58-1] (carbon oxysulfide), COS, is a colorless gas that is odorless when pure however, it has been described as having a foul odor. Physical constants and thermodynamic properties are Hsted ia Table 1 (17,18). The vapor pressure has been fitted to an equation, and a detailed study has been made of the phase equiUbria of the carbonyl sulfide—propane system, which is important ia the purification of propane fuel (19,20). Carbonyl sulfide can be adsorbed on molecular sieves (qv) as a means for removal from propane (21). This approach has been compared to the use of various solvents and reagents (22). 

Some properties of selected vanadium compounds are Hsted in Table 1. Detailed solubiUty data are available (3), as are physical constants of other vanadium compounds (4). Included are the lattice energy of several metavanadates and the magnetic susceptibiUty of vanadium bromides, chlorides, fluorides, oxides, and sulfides (5). 

The physical and thermodynamic properties of carbon monoxide are well documented in a number of excellent summaries (1 8). The thermochemical data cited here are drawn predominantly from references 1—3 physical property data from reference 5. A summary of particularly useful physical constants is presented in Table 1. 

Properties of T2O. Some important physical properties of T2O are Hsted in Table 2. Tritium oxide [14940-65-9] can be prepared by catalytic oxidation of T2 or by reduction of copper oxide using tritium gas. T2O, even of low (2—19% T) isotopic abundance, undergoes radiation decomposition to form HT and O2. Decomposition continues, even at 77 K, when the water is fro2en. Pure tritiated water irradiates itself at the rate of 10 MGy/d (10 rad/d). A stationary concentration of tritium peroxide, T2O2, is always present (9). AH of these factors must be taken into account in evaluating the physical constants of a particular sample of T2O. 

Nitrile rubbers are produced over a wide range of monomer ratios and molecular weights, so thek physical constants and basic polymer properties also cover a range of values. Some of the more widely used properties are Hsted ki Table 1. 

The physical properties of the synthetic glycosyl derivatives of l-asparagine, L-serine, and L-threonine are reported in Tables I-V. Derivatives characterized otherwise, but without m.p. and optical rotation, have also been included. Whenever more than one reference is given, the physical constants are taken from the references printed in bold letters. The abbreviations used in the m.p. column are as follows foam., foaming dec., decomposing and soft., softening. 

Mineral Oil Hydraulic Fluids and Polyalphaolefin Hydraulic Fluids. Limited information about environmentally important physical and chemical properties is available for the mineral oil and water-in-oil emulsion hydraulic fluid products and components is presented in Tables 3-4, 3-5, and 3-7. Much of the available trade literature emphasizes properties desirable for the commercial end uses of the products as hydraulic fluids rather than the physical constants most useful in fate and transport analysis. Since the products are typically mixtures, the chief value of the trade literature is to identify specific chemical components, generally various petroleum hydrocarbons. Additional information on the properties of the various mineral oil formulations would make it easier to distinguish the toxicity and environmental effects and to trace the site contaminant s fate based on levels of distinguishing components. Improved information is especially needed on additives, some of which may be of more environmental and public health concern than the hydrocarbons that comprise the bulk of the mineral oil hydraulic fluids by weight. For the polyalphaolefin hydraulic fluids, basic physical and chemical properties related to assessing environmental fate and exposure risks are essentially unknown. Additional information for these types of hydraulic fluids is clearly needed. 

The diffusivities thus obtained are necessarily effective diffusivities since (1) they reflect a migration contribution that is not always negligible and (2) they contain the effect of variable properties in the diffusion layer that are neglected in the well-known solutions to constant-property equations. It has been shown, however, that the limiting current at a rotating disk in the laminar range is still proportional to the square root of the rotation rate if the variation of physical properties in the diffusion layer is accounted for (D3e, H8). Similar invariant relationships hold for the laminar diffusion layer at a flat plate in forced convection (D4), in which case the mass-transfer rate is proportional to the square root of velocity, and in free convection at a vertical plate (Dl), where it is proportional to the three-fourths power of plate height. 

In order to understand the mechanical properties of polymers it is useful to think of them in terms of their viscoelastic nature. Conceptually we can consider a polymeric item as a collection of viscous and elastic sub-components. When a deforming force is applied, the elastic elements deform reversibly, while the viscous elements flow. The balance between the number and arrangement of the different components and their physical constants controls the overall properties. We can exploit these relationships to create materials with a broad array of mechanical properties, as illustrated briefly by the following examples. 

Physical Constants, Conversion Factors, and Properties of Nuclei (Tables A1.1—A1.4)... 

Physical and Chemical Properties. Most of the important physical-chemical properties of acrylonitrile have been determined (see Chapter 3). However, the partitioning of acrylonitrile between the air and water has been evaluated by using an estimated value for a Henry s law constant. This general approach assumes that the concentration of the chemical in water is low. Because acrylonitrile is relatively soluble in water, this approach may not be accurate. Experimental measurement of the partition coefficient for acrylonitrile at water-air interfaces would be useful in refining models on the behavior of acrylonitrile in the environment. 

The major goals of recent studies of the physical binding to DNA of BP and DMBA metabolites and metabolite models are to determine (1) the magnitudes of the binding constants, (2) the conformations of physical complexes which are formed and the nature of DNA binding sites, (3) how DNA structure and environment influence physical binding, (4) how the structure of hydrocarbon metabolites influences physical binding properties, (5) whether the... 

The major differences between behavior profiles of organic chemicals in the environment are attributable to their physical-chemical properties. The key properties are recognized as solubility in water, vapor pressure, the three partition coefficients between air, water and octanol, dissociation constant in water (when relevant) and susceptibility to degradation or transformation reactions. Other essential molecular descriptors are molar mass and molar volume, with properties such as critical temperature and pressure and molecular area being occasionally useful for specific purposes. A useful source of information and estimation methods on these properties is the handbook by Boethling and Mackay (2000). 

There is a continuing effort to extend the long-established concept of quantitative-structure-activity-relationships (QSARs) to quantitative-structure-property relationships (QSPRs) to compute all relevant environmental physical-chemical properties (such as aqueous solubility, vapor pressure, octanol-water partition coefficient, Henry s law constant, bioconcentration factor (BCF), sorption coefficient and environmental reaction rate constants from molecular structure). 

The reader can deduce the fate of any desired discharge pattern by appropriate scaling and addition. It is important to emphasize that because the values of transport velocity parameters are only illustrative, actual environmental conditions may be quite different thus, simulation of conditions in a specific region requires determination of appropriate parameter values as well as the site-specific dimensions, reaction rate constants and the physical-chemical properties which prevail at the desired temperature. 

---