Thermodynamic Properties of Nitric Acid and Its Hydrates

Table 2. Thermodynamic Properties of Nitric Acid and Its Hydrates...

The thermodynamic properties of nitric acid and its hydrates are given in Table 2 (Refs 32 34)... 

The bare proton has an exceedingly small diameter compared with other cations, and hence has a high polarising ability, and readily forms a bond with an atom possessing a lone pair of electrons. In aqueous solution the proton exists as the H30+ ion. The existence of the H30+ ion in the gas phase has been shown by mass spectrometry [4], and its existence in crystalline nitric acid has been shown by NMR [5], Its existence in aqueous acid solution may be inferred from a comparison of the thermodynamic properties of HC1 and LiCl [6]. The heat of hydration of HC1 is 136 kcal mole"1 greater than that of LiCl, showing that a strong chemical bond is formed between the proton and the solvent, whereas the molar heat capacity, molar volume and activity coefficients are similar,... 

It is convenient to use phase diagrams [46] to represent the thermodynamic properties that determine the stability and equilibrium composition of water-containing aerosols. The properties of interest are the temperature, the vapour pressure and composition of the various components in the condensed phases. This is particularly important with respect to the composition and stability of the various hydrates formed at low temperature in the nitric acid-water [47] and sulfuric acid-water binary systems [48], and the ternary systems HjSO/HNOj/HjO and HjSO/HCl/HjO [49],... 

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