Crystallization of Silver Chromate from Ethanol Via Salt Metathesis Reactions ofSolubilized Precursors

摘要

Admixture of aqueous solutions of silver nitrate and potassium chromate resultsin immediate precipitation of silver chromate as a red-brown microcrystalline powder, while addition of aqueous silver nitrate solution to a solution of potassium chromate/18-crown-6 in ethanol gives a bright-red precipitate. X-ray powder diffraction shows both materials to be orthorhombic silver chromate. The ethanol-derived sample displays broader diffraction peaks, suggesting smaller crystallite size. Scanning electron microscopy confirms this. The ethanol-derived sample appears amorphous, while the aqueous sample displays well-faceted