Gold(III) hydroxide, gold trihydroxide, or gold hydroxide is an

inorganic compound In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemist ...

, a hydroxide of gold, with formula Au(OH)₃. It is also called auric acid with formula H₃AuO₃. It is easily dehydrated above 140 °C to

gold(III) oxide Gold(III) oxide (Au2O3) is an inorganic compound of gold and oxygen with the formula Au2O3. It is a red-brown solid that decomposes at 298 °C. According to X-ray crystallography, AuO features square planar gold centers with both 2- and 3- ...

. Salts of auric acid are termed aurates. Gold hydroxide is used in medicine, porcelain making, gold plating, and daguerrotypes. Gold hydroxide deposited on suitable carriers can be used for preparation of gold catalysts. Gold hydroxide is a product of electrochemical corrosion of gold metalization subjected to moisture and positive electric potential; it is one of the corrosion failure modes of microelectronics. Voluminous gold hydroxide is produced from gold metalization; after the layer grows thick it may spall, and the conductive particles may cause short circuits or leakage paths. The decreased thickness of the gold layer may also lead to an increase in its electrical resistance, which can also lead to electrical failure.

Preparation and reactions

Gold(III) hydroxide is produced by the reaction of

chloroauric acid Chloroauric acid is an inorganic compound with the chemical formula . It forms hydrates . Both the trihydrate and tetrahydrate are known. Both are orange-yellow solids consisting of the planar anion. Often chloroauric acid is handled as a solutio ...

with an alkali, such as

sodium hydroxide Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations and hydroxide anions . Sodium hydroxide is a highly caustic base and alkali ...

: :HAuCl₄ + 4NaOH → Au(OH)₃ + 4NaCl + H₂O Gold(III) hydroxide reacts with ammonia to produce

fulminating gold Fulminating gold is a light- and shock-sensitive yellow to yellow-orange amorphous heterogeneous mixture of different polymeric compounds of predominantly gold (III), ammonia, and chlorine that cannot be described by a chemical formula. Here, the w ...

, an explosive compound.

References

Gold(III) compounds Hydroxides {{Inorganic-compound-stub