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  2. Aqua regia - Wikipedia

    en.wikipedia.org/wiki/Aqua_regia

    Aqua regia dissolves gold, although neither constituent acid will do so alone. Nitric acid is a powerful oxidizer, which will dissolve a very small quantity of gold, forming gold(III) ions (Au 3+). The hydrochloric acid provides a ready supply of chloride ions (Cl −), which react with the gold ions to produce tetrachloroaurate(III) anions ...

  3. Gold parting - Wikipedia

    en.wikipedia.org/wiki/Gold_parting

    It was during the medieval period that distillation was discovered and the first description of nitric acid production was given by Pseudo-Geber in the Summa perfectionis, 1330. Nitric acid is able to dissolve silver. The addition of sal ammoniac to nitric acid creates aqua regia and this acid is able to dissolve gold. Both acids are used in ...

  4. Gold compounds - Wikipedia

    en.wikipedia.org/wiki/Gold_compounds

    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 ...

  5. Gold - Wikipedia

    en.wikipedia.org/wiki/Gold

    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 ...

  6. Nitric acid - Wikipedia

    en.wikipedia.org/wiki/Nitric_acid

    Nitric acid is an inorganic compound with the formula H N O 3. It is a highly corrosive mineral acid. [ 6 ] The compound is colorless, but samples tend to acquire a yellow cast over time due to decomposition into oxides of nitrogen. Most commercially available nitric acid has a concentration of 68% in water.

  7. Acid test - Wikipedia

    en.wikipedia.org/wiki/Acid_test

    Testing for gold with acid capitalizes on gold's status as a noble metal, resistant to corrosion, oxidation, or acid. The procedure includes rubbing the gold-colored item on black stone, leaving a visible mark. The mark undergoes scrutiny by applying nitric acid, which dissolves the mark of any item not gold, stainless steel, zinc, tungsten ...

  8. Gold extraction - Wikipedia

    en.wikipedia.org/wiki/Gold_extraction

    Alternative methods exist for parting gold. Silver can be dissolved selectively by boiling the mixture with 30% nitric acid, a process sometimes called inquartation. Affination is a largely obsolete process of removing silver from gold using concentrated sulfuric acid. [8] Electrolysis using the Wohlwill process is yet another approach.

  9. Nitratoauric acid - Wikipedia

    en.wikipedia.org/wiki/Nitratoauric_acid

    Nitratoauric acid, hydrogen tetranitratoaurate, or simply called gold(III) nitrate is a crystalline gold compound that forms the trihydrate, HAu(NO 3) 4 ·3H 2 O or more correctly H 5 O 2 Au(NO 3) 4 ·H 2 O. [3] [2] This compound is an intermediate in the process of extracting gold. [4] In older literature it is also known as aurinitric acid. [5]