Density, Surface Tension, and Refractive Index of Aqueous Ammonium Oxalate Solutions from 293 K to 333 K

Abstract

Density d, surface tension γ, and refractive index n of ammonium oxalate aqueous solutions of concentrations up to saturation have been measured in the temperature range between 293 K and 333 K. The results of d, γ, and n are fitted as functions of solution concentration. It was found that the first- and second-order equations relating these quantities with solution concentration can satisfactorily be used to describe the data.

Physical Properties (Density, Excess Molar Volume, Viscosity, Surface Tension, and Refractive Index) of Ethanol + Glycerol

“…Next, several drops of distilled water were placed on the prism surface using a plastic syringe and were covered with a cap. The refractive index of the distilled water was then measured at 294 K and was set at 1.333, which agrees well with the value reported in the literature. , …”

“…The refractive index of the distilled water was then measured at 294 K and was set at 1.333, which agrees well with the value reported in the literature. 16,17 All measurements were made at atmospheric pressure and 294 K. The temperature was kept constant to within ( 0.1 K by circulating water into the instrument through thermostatically controlled bath (Techne RB-12). Each measurement was repeated at least three times and then averaged with a repeatability of within 0.1 %.…”

Density and Viscosity of Undersaturated, Saturated, and Supersaturated Aqueous Ammonium Oxalate Solutions from 287 K to 325 K

“…Recently, the authors (Frej et al, 1998) reported experimental data on density, surface tension, and refractive index for dilute aqueous ammonium oxalate solutions. However, until now no data have been published for its supersaturated solutions.…”

On the dimensions of species participating in the growth of ammonium oxalate monohydrate crystals from viscosity data of concentrated aqueous solutions

“…The method of preparation of solutions and measurement of viscosity of ammonium oxalate solutions has been described in detail elsewhere [10,11]. Briefly, aqueous ammonium oxalate solutions were prepared in doubledistilled water using analytically pure compounds produced by Polish Chemical Reagents, Gliwice, Poland.…”

“…Ammonium oxalate monohydrate is an excellent model compound for such studies because it crystallises from aqueous solutions in a relatively simple structure (orthorhombic with unit cell constants: a = 0.8035 nm, b = 1.0309 nm, c = 0.3795 nm [9]), and growth morphology composed of {100}, {010} and {110} pyramidal and {021} prism faces [6,7]. In view of lack of available experimental data on the physical properties of aqueous solutions, the authors have recently investigated some of the physical properties of dilute [10] and concentrated aqueous ammonium oxalate solutions [11].…”