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Gold is unaffected by most acids. It does not react with hydrofluoric, hydrochloric, hydrobromic, hydriodic, sulfuric, or nitric acid. It does react with selenic acid, and is dissolved by aqua regia, a 1:3 mixture of nitric acid and hydrochloric acid. Nitric acid oxidizes the metal to +3 ions, but only in minute amounts, typically undetectable ...
The reaction with hydrochloric acid is an equilibrium reaction that favors formation of tetrachloroaurate(III) anions. This results in a removal of gold ions from solution and allows further oxidation of gold to take place. The gold dissolves to become chloroauric acid. In addition, gold may be dissolved by the chlorine present in aqua regia.
An acid test is a qualitative chemical or metallurgical assay utilizing acid. Historically, it often involved the use of a robust acid to distinguish gold from base metals . Figuratively, the term represents any definitive test for attributes, such as gauging a person's character or evaluating a product's performance.
It is sometimes applied more broadly to any metallic or semimetallic element that does not react with a weak acid and give off hydrogen gas in the process. This broader set includes copper, mercury, technetium, rhenium, arsenic, antimony, bismuth, polonium, gold, the six platinum group metals, and silver.
Copper and silver will react with nitric acid; but because nitric acid is an oxidizing acid, the oxidizing agent is not the H + ion as in normal acids, but the NO 3 − ion. Comparison with standard electrode potentials
It is an electrolytic process using pure gold for the cathode (or titanium as a starter cathode) and chloroauric acid (gold chloride-hydrochloric acid) as the electrolyte; this is made by dissolving gold with chlorine gas in the presence of hydrochloric acid. Gold is dissolved at the anode, and pure gold, traveling through the acid by ion ...
Example, the reaction of mesitylene with phenylacetylene: [31] Gold(III) chloride can be used for the direct oxidation of primary amines into ketones, such as the oxidation of cyclohexylamine to cyclohexanone. [5] This reaction is pH sensitive, requiring a mildly acidic pH to proceed, however, it does not require any additional steps. [5]
Gold(III) acetate, also known as auric acetate, is a chemical compound of gold and acetic acid. It is a yellow solid that decomposes at 170 °C to gold metal. This decomposition of gold(III) acetate has been studied as a pathway to produce gold nanoparticles as catalysts. [3]