Aqua Regia

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Aqua Regia (Latin, “royal water”), mixture of concentrated hydrochloric and nitric acids, containing one part by volume of nitric acid to three parts of hydrochloric acid. Aqua regia was used by the alchemists and its name is derived from its ability to dissolve the so-called noble metals, particularly gold, which are inert to either of the acids used separately. It is still occasionally used in the chemical laboratory for dissolving gold and platinum.

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