Growth of Oxalic Acid Single Crystals from Solution: Solvent Effects on Crystal Habit

Abstract

Single crystals of oxalic acid dihydrate are difficult to grow from pure water solution, but good single crystals of the material may be obtained by growth from mixtures of acetone and water. The solvent markedly affects the crystal habit. Crystals grown in mixtures of acetone and water develop the prismatic habit, while those grown in water alone develop the tabular or equant habit. The forms {001}, {110}, and {101} predominate in all cases. Single crystals of anhydrous oxalic acid may also be grown from solution in glacial acetic acid, although specimens more than 2 centimeters in length are difficult to produce. down their lengths, the density and calcium carbonate content determined on 55 Abstract. Three South Atlantic deep sea cores have been dated by the carbon-14 technique, and rates of accumulation of clay and calcium carbonate have been determined. The highest eupelagic clay rates for the Atlantic found to date are in the Argentine Basin, and the lowest are on the Mid-Atlantic Ridge. Abstract. Three South Atlantic deep sea cores have been dated by the carbon-14 technique, and rates of accumulation of clay and calcium carbonate have been determined. The highest eupelagic clay rates for the Atlantic found to date are in the Argentine Basin, and the lowest are on the Mid-Atlantic Ridge.

High variability of the heterogeneous ice nucleation potential of oxalic acid dihydrate and sodium oxalate

“…Oxalic acid dihydrate crystals that were generated in a different manner, i.e., by crystallisation from less supersaturated aqueous solution droplets at T = 266 K over a timescale of many hours, did not reveal such a high deposition mode ice activity when cooled to 244 K as those particles that have rapidly crystallised from highly supersaturated solution droplets directly at 244 K. In order to give reason for their outstanding ice-nucleability, one might therefore also speculate that polycrystalline particles with numerous defects are formed when oxalic acid dihydrate particles rapidly crystallise from highly supersaturated solution droplets at low temperatures. Temperature and supersaturation are known to be key parameters that influence size and shape of crystals grown from aqueous solutions (Omar and Ulrich, 2006;Torgesen and Strassburger, 1964). This interpretation would be in agreement with the results from the study by Shilling et al (2006) about heterogeneous ice nucleation on spray-deposited ammonium sulphate and maleic acid particles.…”

Identification of hydrogen bond modes in polarized Raman spectra of single crystals of α‐oxalic acid dihydrate

“…[16]. According to Winchell, [17] the optical plane and the X optical indicatrix are normal to the crystallographic b-axis, and the angle that the optical indicatrix Z closes with the crystallographic c-axis is 14 • 42 .…”

Spectres d'absorption de l'acide oxalique dihydraté dans l'infrarouge lointain

“…En diminuant le taux d'évaporation (température du bain voisine de 25°C) nous avons obtenu des cristaux limpides d'un volume de plan (010) de la structure de l'acide oxalique dihydraté (COOH)2, 2 H20 d'après Delaplane et Ibers [2]. plus rapidement en ajoutant de l'acétone à l'eau comme l'ont montré J. L. Torgesen et J. Strassburger [3].…”