Influence of Phosphate-Based Salts on Enthalpy of Dilution and Isentropic Compressibility Properties of Saccharides and Their Derivatives in Aqueous Solutions

Abstract

The standard enthalpies of dilution (Δ dil H°) and isentropic compressibilities (K°s ,2 ) of some saccharides and their derivatives; (−)-D-ribose, (+)-D-glucose, 2-deoxy-D-glucose, (+)-methyl α-D-glucopyranoside, (+)-maltose monohydrate, and (+)-raffinose pentahydrate (solutes) were determined from heat change (q) and speed of sound (u) data measured, respectively, in (0.05, 0.15, 0.25, and 0.35) mol•kg −1 and (0.5, 1.0, 1.5 and 2.0) mol•kg −1 aqueous solutions of sodium phosphate (NaH 2 PO 4 ), ammonium phosphate (NH 4 H 2 PO 4 ) monobasic salts, and potassium phosphate (K 3 PO 4 ) tribasic salt at T = 288.15− 318.15 K at P = 0.1 MPa. Other parameters such as transfer values (Δ t (Δ dil H°), Δ t K°s ,2 ), change in heat capacity (Δ dil C°p ,2,m ), and hydration numbers (n w ) were also derived to rationalize the molecular interactions in mixtures of saccharide and derivative and phosphate-based salts.These studies are important to understand various interactions in terms of changing cation (Na + , NH 4 + , and K + ) and anion (H 2 PO 4 − and PO 4 3− ) size, ionic strength, and influence of salts on water structure.

Investigation of the Effect of Alkyl Chain Length on Molecular Interactions Between Methyl Benzoate with Alcohols: A Study of Physicochemical Properties

“…These increase with increasing x 1 and decrease with increasing temperature. According to the literature, speeds of sound u can be used to calculate the isentropic compressibility κ s of the mixture, which often is employed to study the molecular interaction of the system [43]. Therefore, the isentropic compressibility κ s of the studied mixtures were calculated and listed in Table S2 by means of the Laplace equation as follows [44] then the isentropic compressibility deviations ∆κ s of the studied systems were also calculated by the following equation and are listed in Table S2 where κ s is the isentropic compressibility of the mixture.…”