Internal pressure and cohesive energy density for binary non-electrolyte mixtures

Internal Pressure of Liquids and Solutions

“…For the former two mixtures self-interaction of the water outweighs the mutual interactions, but the opposite is the case for the latter two mixtures, 87 so that different signs of P int E are expected. Similarly, Acevedo et al 88 calculated P int E in terms of mole fraction prorating of the P int values of the components and arrived at negative P int E for mixtures of n-pentane with dichloromethane and methyl acetate, 2-propanol with methyl acetate, and 1-butylamine with 1,4-dioxane. Results were interpreted in terms of appreciable mutual interactions, but these do not appear to take place in these systems (except, perhaps, for 2-propanol + methyl acetate).…”

Chapter 16. Internal Pressure and Internal Energy of Saturated and Compressed Phases

“…For polar liquids the values of n vary within the range (0.32 to 1.64). Acevedo et al 43 found that the values of n for associated fluids are less than n<1, while for non-polar liquids n is approximately 1. For strongly associated liquids (especially for H-bonded liquids), n is much less than 1.…”

Isothermal compressibility studies of binary solution of cycloheptane and methanol

“…Internal pressure has been found to be a useful parameter for studying the solute-solvent interactions of bio-molecules in aqueous medium [9][10] . This has been applied in the cases of liquids and liquid mixtures initially by Hildebrand et al [1] and subsequently by several workers [11][12][13][14][15] . Internal pressure turns out to be a measure of the totality of forces including dispersion, repulsion, ionic and dipolar interactions that contribute to the overall cohesion in electrolyte and non-electrolyte aqueous solutions and liquid mixtures.…”