Morgan pure

Unfortunately, phases of geochemical interest are not ideal. As well, aqueous species do not occur in a pure form, since their solubilities in water are limited, so a new choice for the standard state is required. For this reason, the chemical potentials of species in solution are expressed less directly (Stumm and Morgan, 1996, and Nordstrom and Munoz, 1994, e.g., give complete discussions), although the form of the ideal solution equation (Eqn. 3.4) is retained. 

Figure 4.9 Electrode current versus electrode potential curves for solutions containing O2 (a) in otherwise pure water (b) in the presence of Fe. In (a) the net current is close to zero over a wide range of potential, so it is difficult to locate the equilibrium potential. In (b) the measured equilibrium potential is a mixed potential, Em, obscuring the true equilibrium potential of the system, Feq (Stumm and Morgan, 1996). Reproduced by permission of Wiley, New York...

Fig. 7. Paramagnetic enhancements to solvent NMRD profiles for Fe(H20)g" " solutions at 298 K with (A) pure water and ( ) 60% glycerol. The lines represent the best fit curves using the Solomon-Bloembergen-Morgan equations [Eqs. (l)-(6)] 36).

Stumm WS, Morgan JJ (1996) Aquatic chemistry, 3rd edn,Wiley, New York Templeton DF, Ariese R, Cornells LG, Danielson H, Muntau H, Van Leeuwen H, Lobinski R (2000) Guidelines for terms related to chemical speciation and fractionation. Pure Appl Chem... 

The acidophilic Fe reducer Addiphilium cryptum JF-5 reductively disssolved pure schwertmannite and sulphate was released whereas arsenated and chromated schwertmannite was not reduced, and so remained inactivated, probably because of their biotoxicity (Regenspurg et al. 2002). A method for Fe removal as magnetite, recently proposed by Morgan et al. (2003), consists of oxidizing it at pH 10.5 in the presence of magnetite seeds. 

In any attempt to determine the structure of an unknown biological compound, researchers must deal with two fundamental problems (1) If you don t know what it is, how do you know if it is pure (2) If you don t know what it is, how do you know that your extraction and purification conditions have not changed its structure Morgan addressed problem 1 through several methods. One method is described in his paper as observing constant analytical values after fractional solubility tests (p. 312). In this case, analytical values are measurements of chemical composition, melting point, and so forth. 

Refs. [i] Muller P (1994) Pure Appl Chem 66 1077 [ii] Cotton FA, Wilkinson G, Murillo CA, Bochmann M (1999) Advanced inorganic chemistry. Wiley-Interscience, New York [iii] Morgan GT, Drew HDK (1920) J Chem Soc 117 1456... 

Now that solubility and vapor pressure have been defined, consider how a volatile chemical partitions, or distributes itself, between water and air phases at equilibrium. In general, a partition coefficient is the ratio of the concentrations of a chemical in two different phases, such as water and air, under equilibrium conditions. The Henry s law constant, H (or KH), is a partition coefficient usually defined as the ratio of a chemical s concentration in air to its concentration in water at equilibrium. [Occasionally, a Henry s law constant is interpreted in an inverse fashion, as the ratio of a chemical s concentration in water to its concentration in air see, e.g., Stumm and Morgan (1981, p. 179). Note that in that table, KH is equivalent to 1/H as H is defined above ] Values of Henry s law constants are tabulated in a variety of sources (Lyman et al, 1990 Howard, 1989, 1991 Mackay and Shiu, 1981 Hine and Mookerjee, 1975) Table 1-3 lists constants for some common environmental chemicals. When H is not tabulated directly, it can be estimated by dividing the vapor pressure of a chemical at a particular temperature by its aqueous solubility at that temperature. (Think about the simultaneous equilibrium among phases that would occur for a pure chemical in contact with both aqueous and gas phases.) Henry s law constants generally increase with increased temperature, primarily due to the significant temperature dependency of chemical vapor pressures as previously mentioned, solubility is much less affected by the changes in temperature normally found in the environment. 

In 1995, Morgan et al. synthesized a layered aluminophosphate compound by using a chiral cobaltammine complex as the template for the first time.[61] Recently, the Jilin group has synthesized a number of 2-D layered and 3-D open-framework metal phosphates by using a racemic mixture or an optically pure chiral metal complex as the template, and has systematically studied the chirality transfer from the guest chiral complex templates to the host inorganic open frameworks.1901 Table 7.15 lists some metal phosphates and oxides with open-framework structures templated by optically pure or racemic cobalt ammine complexes. 

Figure 7.3. Electrode current in pure water (aerated) as a function of potential. Net current is close to zero over a wide range of electrode potential, making it difficult to locate the equilibrium potential, E,. (Adapted from W. Stumm and J. J. Morgan. 1981. Aquatic Chemistry. 2nd ed. New York Wiley. Used with permission.)...

Equating the Nusselt numbers for pure natural convection and pure forced convection provides a good estimate of the Ra-Re curve along which mixed convection effects are most important, as already discussed. After a careful study of available data, Morgan [198] proposed the following equation for forced convection heat transfer from a cylinder for cross flow in a low-turbulence airstream ... 

Figure 2.47 Solubility of van-valence metal oxides vs. pH of solution in pure water (Stumm and Morgan, 1981).

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