Other Aspects of Water Structure

Attention is drawn to the aspect of water structure relating to the effects of adding water to an organic liquid. Bullock and Tuck explained the nuclear magnetic resonance spectra of a solution of water in tri-n-butyl phosphate by postulating the formation of linear and chain polymers of varying complexity according to the amount of water added  

Johnson, Christian, and Affsprung determined the solubility of water in liquids as a function of the total vapor pressure at 25°C in the low-water-concentration region. The liquids were nitrobenzene, dibutyl phthalate, tributyl phosphate, N,N-dimethylaniline, tributylamine, aniline, N,N-dimethylcy-clohexylamine, benzyl alcohol, cyclohexanone, and methyl phenyl ketone. These authors do not refer to the structure of water itself. They assumed that water molecules are present in solution as an equilibrium mixture of monomers and not more than two polymeric species each of which obeys Henry s law.  

It was stated that the Henry s law relationships employed are strictly valid only in the limit of infinite dilution. It was pointed out that even in dilute solutions there is no unambiguous way of assessing the relative importance of physical and chemical contributions to deviations from Henry s law. In my opinion there is no line of demarcation, physical-chemical. Confusion will prevail so long as the concept Henry s law at infinite dilution is uncritically held. 

Those authors drew attention to the few quantitative studies on the complexity of water in nonaqueous media, and they cited references. They concluded that water is approximately 20% associated in nitrobenzene at saturation concentration at 25°C, although Hogfeldt and Bolander stated that water is primarily monomeric in 

as was suggested, two molecules of water, (H2O) units, form the hydrogen-bonded complex shown in the diagram, the number of moles of this complex per mole of nitrobenzene originally taken cannot be more than 0.0081 at p near p° . If the remainder of the liquid is deemed to be nitrobenzene as it exists in the original pure liquid taken, why does it not continue to absorb more water and form more of the complex How can one escape the conclusion that under the conditions of equilibrium specified one molecule, (H2O) unit, of water is using 61 molecules of nitrobenzene on a time-average basis  

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