Title: Gold Trihydroxide

CAS Registry Number: 1303-52-2

Additional Names: Auric hydroxide

Molecular Formula: AuH3O3

Molecular Weight: 247.99

Percent Composition: Au 79.43%, H 1.22%, O 19.35%

Line Formula: Au(OH)3

Literature References: Usually contains about 3H2O and hence about 65% gold. May be prepd in lab according to the equation 2KAuCl4 + 3Na2CO3 + 3H2O ® 2Au(OH)3 + 6NaCl + 2KCl + 3CO2: Lydén, Z. Anorg. Allg. Chem. 240, 157 (1939).

Properties: Brown powder; dec by sunlight to metallic gold; also slowly dec with age or at 100°, and completely at 250°. Practically insol in water. Sol in soln of NaCN, in HCl or concd HNO3. With NH3 yields gold fulminate which explodes easily in dry form. Protect from light.

Use: In gold-plating solns; for decorating porcelains.