1303-58-8 Digold trioxide

Details:

Product Name: Digold trioxide
Synonyms: GOLD OXIDE;GOLD SESQUIOXIDE;Auric oxide;Gold(III) oxide hydrate;GoldoxideorangebrownpowderGoldgehalt;Gold(III) oxide, 99.9%;Gold trioxide;Gold(III)oxide,99%
CAS: 1303-58-8
MF: Au2O3
MW: 441.93
EINECS: 215-122-1
Product Categories: Industrial/Fine Chemicals;Gold;Metal and Ceramic Science;Oxides;metal oxide;chemical reaction,pharm,electronic,materials

Mol File: 1303-58-8.molDigold trioxide Chemical Properties

Melting point  150°C
form  Powder
color  Brown
Water Solubility  Insoluble in water. Soluble in HCl, HNO₃ and in NaCN solution.
Merck  14,4524
CAS DataBase Reference 1303-58-8(CAS DataBase Reference)
EPA Substance Registry System Gold oxide (Au2O3) (1303-58-8)
Safety Information
Hazard Codes  Xi
Risk Statements  36/38
Safety Statements  26-36
RIDADR  UN 3263 8/PG 3
WGK Germany  3

TSCA  YesDigold trioxide Usage And Synthesis

General description Brown powder; decomposes slowly on exposure to sunlight or by heating at 150°C; begins to release oxygen at 110°C; fully decomposes to metallic gold at 250°C; insoluble in water; soluble in hydrochloric and concentrated nitric acids; also soluble in aqueous solutions of sodiumor potassium cyanide.

Preparation Gold(III) oxide is prepared by heating gold(III) hydroxide, Au(OH)3 at 130 to 140°C

Digold trioxide

Chemical Properties Brownish-black powder, decomposed by heat.Keep in dark bottle. Soluble in hydrochloric acid; insoluble in water.
Uses Gold plating
Purification Methods The most probable impurities are SO4and Cl-ions. Dissolve it in strong boiling KOH solution (ca 5M) and precipitate (care) with excess of 3N H2SO4. Then shake and centrifuge, resuspend in H2O and repeat the washing several times until free from SO4 and Cl ions. This gives a wet oxide which is dried in air, but decomposes to free gold in sunlight. It is advisable to keep it wet as it decomposes on drying (analyse wet sample). Store it away from light in the presence of H2O vapour. It evolves O2 at 110o. It is insoluble in H2O but soluble in HCl and conc HNO3.