Hydrogen bonding phase diagram

As discussed in Chapter 6, water forms strong hydrogen bonds and these lead to a number of important features of its atmospheric behavior. All three phases of water exist in the atmosphere, and the condensed phases can exist in equilibrium with the gas phase. The equilibria between these phases is summarized by the phase diagram for water. Fig. 7-9. 

This work raises some interesting issues. The first is that the stoichiometry of a complex is not necessarily the most obvious. For example, it was reported initially that phthalic acid formed a 2 1 complex with alkoxystil-bazole [34], when in fact a careful study carried out by constructing a binary phase diagram (Fig. 11) revealed the complex to have a 1 1 ratio of the two components [35]. The reluctance of the system to form the more obvious 2 1 complex may relate to the presence of intramolecular hydrogen bonding or could even relate to the change in the pfCa of the second acid proton on com-plexation. 

Abstract—The equilibrium diagrams of the binary systems of sulphuric add with nitromethane and with o-y m- and p-nitrotoluene have been investigated. It has been shown that addition compounds of the type 1 1 are formed in these systems, analogous to the compound sulphuric acid-nitrobenzene (Chebbuuez Helv, Chim, Acta 1923 6 281 and Masson J. Chem. Soc. 1931 3201)t The formation of these addition compounds is due to hydrogen bonding between the components, rather than to proton transfer. Their stability in the crystalline phase seems to be contradictory to the known basicities of mononitrocompounds (Gillespie and Solomons J. Chem. Soc, 1957 1796), because of the effect of temperature on the equilibria in the liquid phase. 

Hydrate phase diagrams for water-hydrocarbon systems provide a convenient overview of the calculation types. These diagrams differ substantially from the normal hydrocarbon phase diagrams primarily due to hydrates and the hydrogen bonds inherent in aqueous systems. The phase diagrams of Section 4.1 provide an overview for the calculation methods in this chapter and the next. 

The phase behavior of hydrocarbon + water mixtures differs significantly from that of normal hydrocarbon mixtures. Differences arise from two effects, both of which have their basis in hydrogen bonding. First, the hydrate phase is a significant part of all hydrocarbon + water phase diagrams for hydrocarbons with a molecular size lower than 9 A. Second, water and hydrocarbon molecules are so different that, in the condensed state, two distinct liquid phases form, each with a very low solubility in the other. 

Fig. 2 Phase diagram of P(A)/P(B) homopolymer hlend, where P(A) and P(B) can form a pseudo dihlock copolymer due to hydrogen bonding [65]...

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