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

Abstract

Experimental data on the density, d, and viscosity, η, of ammonium oxalate aqueous solutions in the range of undersaturation and supersaturation are reported for solutions of saturation concentrations, c s , between 0.36 M and 0.75 M. It was found that the temperature dependence of d for solutions of different saturation concentrations may be described by a first-order equation while that of η may be described by an Arrhenius-type relation. Moreover, for solutions of particular saturation concentrations, c s , both d and η linearly increase with supersaturation.

Investigation of metastable zone width of ammonium oxalate aqueous solutions

“…Filled square shows metastable zone width obtained by isothermal cooling method. Data from density measurements and by isothermal cooling method are from Frej et al [15], and Sangwal and Mielniczek-Brzóska [16]. Finally, it should be mentioned that the values of supersaturation lnS max ≈ σ max obtained from experimental data at saturation temperature T 0 = 303 K by polythermal method, from density measurements and by isothermal method are 0.48, 0.23 and 0.10, respectively.…”

“…The data on metastable zone width of AO solutions based on density measurements were obtained from the experimentally determined densities of aqueous solutions of analytically pure AO by Frej et al [15]. The density measurements were made in range of undersaturation and supersaturation for solutions saturated at temperatures T 0 between 292 and 320 K from a temperature 5 K above T 0 down to the temperature T lim of the onset of nucleation by cooling the solution at a rate of 4 K⋅h −1 .…”

“…[10−14] and the literature cited therein) have investigated the growth behavior of ammonium oxalate monohydrate crystals from aqueous solutions in the absence as well as presence of different bi-and trivalent cationic impurities. Frej et al [15] reported experimental results of density and viscosity of undersaturated and supersaturated aqueous solutions of analytically pure ammonium oxalate (AO) at different saturation temperatures T 0 . Sangwal and MielniczekBrzóska [16] studied the metastable zone width of pure AO aqueous solutions and of solutions containing different bi-and trivalent cationic impurities.…”

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].…”