Apparent Specific Volume and Apparent Specific Refraction of Some Poly(oxyethylene) Glycols in 1,4-Dioxane and Benzene Solutions at 298.15 K

Summary. The density and refractive index of 1,4-dioxane and benzene solutions of poly(oxyethylene) glycols of the type HO-(CH 2 CH 2 O) n -H (n varying from 4 to 36) were measured at 298.15 K. From the experimental data the apparent specific volume and the apparent specific refraction at infinite dilution were calculated. The limiting apparent specific volume and the limiting apparent specific refraction were found to be inversely proportional to the number average molecular weight of solute. From the limiting apparent specific values at the infinite degree of polymerization, the partial molar volume and partial molar refraction of the monomeric unit were calculated. The partial molar volume as well as the partial molar refraction of the investigated compounds at infinite dilution are additive and depend linearly on the number of oxyethylene groups. The volumetric data were analyzed in terms of the intrinsic volume of solute molecules and by a void partial molar volume. The packing density of the investigated compounds approaches a uniform value as the size of the molecules increases and in both solvents limiting values are reached

Apparent molar volume and apparent molar refraction of Mono-, Di-, Tri-, and Tetra(oxyethylene) glycol in aqueous, 1,4-dioxane, and benzene solutions at 298.15K,”Monatshefte fur Chemie,

Summary. The density and refractive index of aqueous, 1,4-dioxane, and benzene solutions of poly (oxyethylene) glycols of the type HO-(CH 2 CH 2 O) n -H (n varying from 1 to 4) were measured at 298.15 K. From these experimental data the apparent molar volume and the apparent molar refraction at infinite dilution were calculated. The limiting apparent molar volume of the investigated compounds in a definite solvent depends linearly on the number of oxyethylene groups. From these data, the volume of the monomeric unit was evaluated and found to be greater in non-aqueous solvents than in water. The limiting apparent molar refraction of the solute for the investigated systems, within the experimental uncertainties, is equal to the molar refraction of the pure solute. The electronic polarizability of the solute molecule depends linearly on the number of monomeric units and the ratio of the electronic polarizability to the molecular van der Waals volume is constant and independent of the number of oxyethylene groups

Rapid Communication Viscosity of aqueous solutions of some alkali cyclohexylsulfamates at 25.0°C

Abstract The dynamic viscosity of aqueous solutions of cyclohexylsulfamic acid and of its lithium, sodium and potassium salts was measured in the concentration range from 0.02 to 0.70 mol dm À3 (the potasssium salt only up to 0.20 mol dm À3 because of its poor solubility) at a temperature of 25.0°C. The data for relative viscosity, which were calculated from the dynamic viscosity, were analysed with the help of the extended Jones-Dole equation and the viscosity coefficients A g , B g and D g were evaluated. The B g coefficients of the salts were divided into their ionic contributions and the ionic B g value for the cyclohexylsulphamic ion was determined. From the viscosity coefficient B g the partial molar Gibbs energy of activation for viscous flow at infinite dilution was calculated for the investigated solutes and interpreted in terms of relative solute effects on the solvent in the ground and in the transition states. Additionally, the hydration number of the solute was determined and some correlation between the transport properties of solutions of cyclohexylsulphamates and their relative sweetness was found

A Conductometric Study of Aqueous Solutions of Some Cyclohexylsulfamates

The electric conductivities of aqueous solutions of the lithium, sodium, potassium and ammonium salts of cyclohexylsulfamic acid were measured from 5 to 35 • C (in steps of 5 • C) in the concentration range 3 × 10 −4 < c/mol-dm −3 < 0.01. Data analysis based on a chemical model of electrolyte solutions yielded the limiting molar conductance ∞ and the association constant K A . Using the known values of the limiting conductances of lithium, sodium and potassium ions, the limiting conductances of the cyclohexylsulfamic ion were evaluated. Total dissociation of the investigated salts in water and negligible hydration of the cyclohexylsulfamate anion are evident