Solids liquid/solid solutions

Atomization The most important difference between a spectrophotometer for atomic absorption and one for molecular absorption is the need to convert the analyte into a free atom. The process of converting an analyte in solid, liquid, or solution form to a free gaseous atom is called atomization. In most cases the sample containing the analyte undergoes some form of sample preparation that leaves the analyte in an organic or aqueous solution. For this reason, only the introduction of solution samples is considered in this text. Two general methods of atomization are used flame atomization and electrothermal atomization. A few elements are atomized using other methods. 

Atomization and Excitation Atomic emission requires a means for converting an analyte in solid, liquid, or solution form to a free gaseous atom. The same source of thermal energy usually serves as the excitation source. The most common methods are flames and plasmas, both of which are useful for liquid or solution samples. Solid samples may be analyzed by dissolving in solution and using a flame or plasma atomizer. 

Polymerization thermodynamics has been reviewed by Allen and Patrick,323 lvin,JM [vin and Busfield,325 Sawada326 and Busfield/27 In most radical polymerizations, the propagation steps are facile (kp typically > 102 M 1 s l -Section 4.5.2) and highly exothermic. Heats of polymerization (A//,) for addition polymerizations may be measured by analyzing the equilibrium between monomer and polymer or from calorimetric data using standard thermochemical techniques. Data for polymerization of some common monomers are collected in Table 4.10. Entropy of polymerization ( SP) data are more scarce. The scatter in experimental numbers for AHp obtained by different methods appears quite large and direct comparisons are often complicated by effects of the physical state of the monomei-and polymers (i.e whether for solid, liquid or solution, degree of crystallinity of the polymer). 

Liquid Liquid Liquid-gas Liquid-liquid Liquid-solid Solution Foam Emulsions Slurry Suspension Metal plating effluent spent acids wash-waters Detergent foam Oil-in-water (e.g. suds) water-in-oil Aqueous effluent from fume scrubbing... 

Dupont, J. (2004) On the solid, liquid and solution structural organization of imidazolium ionic liquids. Journal of the Brazilian Chemical Society, 15 (3), 341-350. 

Sample. This source places no restrictions on target material. Clusters of metals, produced. For example, polyethylene and alumina have been studied as well as refractory metals like tungsten and niobium. Molecular solids, liquids, and solutions could also be used. However the complexity of the vaporization process and plasma chemistry makes for even more complex mixtures in the gas phase. To date the transition metals(1-3) and early members of group 13 (IIIA) and 14 (IVA)( 11-16) have been the most actively studied. 

As was discussed earlier in Section 1.2.8 a complication arises in that two of these properties (solubility and vapor pressure) are dependent on whether the solute is in the liquid or solid state. Solid solutes have lower solubilities and vapor pressures than they would have if they had been liquids. The ratio of the (actual) solid to the (hypothetical supercooled) liquid solubility or vapor pressure is termed the fugacity ratio F and can be estimated from the melting point and the entropy of fusion. This correction eliminates the effect of melting point, which depends on the stability of the solid crystalline phase, which in turn is a function of molecular symmetry and other factors. For solid solutes, the correct property to plot is the calculated or extrapolated supercooled liquid solubility. This is calculated in this handbook using where possible a measured entropy of fusion, or in the absence of such data the Walden s Rule relationship suggested by Yalkowsky (1979) which implies an entropy of fusion of 56 J/mol-K or 13.5 cal/mol-K (e.u.)... 

Core Al solid/liquid, pure/solution (or dispersion) + additives (solvent, emulsifier,...)... 

This part includes a discussion of the main experimental methods that have been used to study the energetics of chemical reactions and the thermodynamic stability of compounds in the condensed phase (solid, liquid, and solution). The only exception is the reference to flame combustion calorimetry in section 7.3. Although this method was designed to measure the enthalpies of combustion of substances in the gaseous phase, it has very strong affinities with the other combustion calorimetric methods presented in the same chapter. 

Chemists pay much less attention to the NMR relaxation rates than to the coupling constants and chemical shifts. From the point of view of the NMR spectroscopist, however, the relaxation characteristics are far more basic, and may mean the difference between the observation or not of a signal. For the quadrupolar nucleides such as 14N the relaxation characteristics are dominated by the quadrupole relaxation. This is shown by the absence of any nuclear Overhauser effect for the 14N ammonium ion despite its high symmetry, which ensures that the quadrupole relaxation is minimized. Relaxation properties are governed by motional characteristics normally represented by a correlation time, or several translational, overall rotational and internal rotational, and thus are very different for solids, liquids and solutions. 

The thermodynamics experiments are subdivided into experiments on calorimetry and heat capacity, Table XVI phase transitions, Table XVII properties of gases, liquids, solids, solutions and mixtures, Table XVIII and finally equilibrium and miscellaneous thermodynamic topics , Table XIX. 

Table XVIII. Experiments on Properties of Gases, Liquids Solids, Solutions and Mixtures...

Fig. 29. Liquidus isotherms (solid) and solid-solution isoconcentration lines (dashed) for -rich liquids. The numbers adjacent to the isoconcentration lines are the values of x in Hgl jtCdxTe(s). The ordinate is the atom fraction of Hg in the liquid phase on a log scale, the abscissa is the atom fraction of Cd in the liquid on a linear scale.

Many chemical reactions, including some of the most important processes in the chemical industry, involve gases. Thirteen million tons of ammonia, for example, are manufactured each year in the United States by the reaction of hydrogen with nitrogen according to the equation 3 H2 + N2 — 2 NH3. Thus, it s necessary to be able to calculate amounts of gaseous reactants just as it s necessary to calculate amounts of solids, liquids, and solutions (Sections 3.4-3.9). 

Liquid-solid solution equilibria at constant pressure... 

Solid-liquid, solid-vapor and liquid-vapor equilibrium curves for pure water (solid curves) and for a solution (dashed curves). The triple point (where solid, liquid, and vapor coexist and at nearly the same temperature as the freezing point) is shifted to lower temperature for the solution. 

Solid Liquid Colloidal solution, sol Sols of metals, sulphur etc., paint, ink. 

Sampling mode (liquid, solid, solution, gas, light-pipe, cryodeposition, bulk, micro) ... 

It has now been demonstrated that many molecules adsorbed on appropriately prepared metal surfaces display Raman cross-sections several orders of magnitude greater than the corresponding quantity for an isolated molecule or from a solution. Together with other surface-sensitive techniques, SERS has catalyzed the study of condensed phases on surfaces. It has demonstrated promise as a vibrational probe of in situ gas-solid, liquid-solid, and solid-solid environments, as well as a high-resolution probe of vacuum-solid interfaces. 

In this book we are concerned only with mass transport, or diffusion, in solids. Self-diffusion refers to atoms diffusing among others of the same type (e.g., in pure metals). Interdiffusion is the diffusion of two dissimilar substances (a diffusion couple) into one another. Impurity diffusion refers to the transport of dilute solute atoms in a host solvent. In solids, diffusion is several orders of magnitude slower than in liquids or gases. Nonetheless, diffusional processes are important to study because they are basic to our understanding of how solid-liquid, solid-vapor, and solid-solid reactions proceed, as well as [solid-solid] phase transformations in single-phase materials. 

Several attempts have been made to determine the symmetry (and hence the conformation of the phosphazene ring) of halogenocyclo-phosphazenes in the solid, liquid, and solution states using infrared and Raman spectroscopy (2, 136, 249, 255, 255a, 422). With some exceptions, there is reasonable agreement between the structures determined by diffraction methods and those predicted by vibrational spectroscopy. The calculation of force constants in N3P3C16 and assignment of vibration frequencies have been discussed (118). 

Strozecka, K., and J - Terpitowski Thermodynamic properties of T1—Sn liquid solid solutions. Roczniki Chem. 39, 663 (1965). 

FIGURE 51 SEM images of YB03 Eu NCs prepared by the liquid-solid-solution method using 8 ml oleic acid at 210 °C for 24 h. Reprinted with permission from Li et al. (2007c). Copyright 2007 Wiley-VCH. 

Absolute reaction rates can be affected by molecular diffusion processes that dictate the rates at which collisional encounter complexes occur before reaction. This affect usually shows up in the way reaction rates depend on the physical form of the reactants (gas, liquid, solid, solution, etc.), particularly on concentrations for reactants in gas or hquid phases. Adsorption of reactants onto surfaces can enhance the effective concentrations of reactive species and/or reduce the dimensionahty of the diffusion process. Classic work by Eigen and Richter (14) showed how restricting diffusion to one or two dimensions can dramatically increase potential reaction rates, and this principle has been applied to the kinetics of protein translocation along DNA chains, for example. See References 15 and 16 for more information. 

V. V. Keussler. Z. Elektrochem. 58, 136-42 (1954). UV spectra of phenol, pure liquid, solid, solutions in CGI4, cyclohexane. 

The laser vaporization approach allows the use of even the most refractory target materials. The source configuration used in Fig. 1 involves a target rod that is rotated and translated in a continuous screw motion to expose fresh metal to the laser beam. This has been found necessary to provide acceptable pulse-to-pulse reproducibility. Target rods of refractory metals, semiconductors, carbon, polyethylene, alumina, and alloys have all been vaporized successfully to make clusters in many laboratories. For some materials a disk target is preferred due to the ease in sample preparation. Molecular solids, liquids, and solutions could also be used, though care must be taken to consider the additional complex plasma chemistry one is likely to encounter. 

Solids, liquids, and solutions exhibit many properties that can only be explained in terms of the action of their surfaces. A surface is actually a boundary, where the mass of one body ends and the mass of another begins. Consider a rising air bubble immersed in a liquid pool. The surface of the air faces a corresponding surface of the liquid the region enclosed by these two surfaces is known as an interface, and it is within this interfacial region that adsorption occurs. There are five types of possible interfaces (43) ... 

The basic principle for solid/liquid and solute/liquid separation by the adsorptive bubble separation processes has been introduced previously. This section further presents fundamental principles on foam phenomena and foam separation cell s operation. 

Refluxing the mixture of purified potassium in r-amyl alcohol for 3-4 hrs. afforded a solution calculated to be 0.19 Af in potassium 2-methyl-2-butoxide and found by titration with standard acid to be 0.16M. The appearance of the solution seems to be dependent upon the condition of the potassium used. Potassium that melts to a bright shiny pool of metal gives a clear light-colored solution of potassium 2-methyl-2-butoxide. If it melts to a crumbly, semi-solid liquid, the solution of alkoxide is darker colored. 

Solubility in Liquid-Solid Solutions Did you notice that the temperature was included in the explanation about the amount of solute that dissolves in a quantity of solvent The solubility of many solutes changes if you change the temperature of the solvent. For example, if you heat water, not only does the sugar dissolve at a faster rate, but more sugar can dissolve in it. However, some solutes, like sodium chloride and calcium carbonate, do not become more soluble when the temperature of water increases. The graph in Figure 11 shows how the temperature of the solvent affects the solubility of some solutes. 

Saturated Solutions if you add calcium carbonate to 100 g of water at 25°C, only 0.0014 g of it will dissolve. Additional calcium carbonate will not dissolve. Such a solution—one that contains all of the solute that it can hold under the given conditions—is called a saturated solution. Figure 12 shows a saturated solution. If a solution is a liquid-solid solution, the extra solute that is added wiU settle to the bottom of the container. It s possible to make solutions that have less solute than they would need to become saturated. Such solutions are unsaturated. An example of an unsaturated solution is one containing 50 g of sugar in 100 g of water at 25°C. That s much less than the 204 g of sugar the solution would need to be saturated. 

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