The ancient alchemists called gold the "king of metals". Gold does not have normal acid, so when it was opened acid, which can dissolve this noble metal, the alchemists called it the"Royal vodka" (Aqua regia is more correctly translated from Latin as "Royal water"). Aqua Regia can dissolve not only the gold, and platinum.
What is Aqua Regia? It is a mixture of two acids - hydrochloric and nitrogen in the ratio of 3:1 (three volume parts of hydrochloric acid to 1 volume part nitric acid). Aqua Regia - yellow liquid with the odor of chlorine and oxides of nitrogen.
First Imperial vodka received Italian alchemist Bonaventure in 1270 it is Curious that at the moment hydrochloric acid was not yet known to science. Tsarskaya vodka then prepared by distilling a mixture of nitrate, copper sulphate and alum with the addition of ammonia.
Oxidative properties of Aqua Regia when storing lost, because in the air it evaporates chlorine, and it is important in the oxidation reactions. Therefore suitable only freshly prepared reagent.
As Aqua Regia effect on precious metals?
By the way...
Gold, in addition to Aqua Regia dissolves in hot concentrated selenium acid:
2Au + 6H2SeO4 = Au2 (SeO4)3 + 3H2 SeO3 + 3H2O.
This is interesting!
A unique property of Aqua Regia was used during the Second World war, the famous Danish physicist and Nobel laureate Niels Bohr. In 1943, fleeing from the Nazi invaders, he was forced to leave Copenhagen. But he held two gold Nobel medal to his fellow German physicists anti-fascists James Franck and max von Laue (medal of the Boron was removed from Denmark earlier). Not risking to take the medals with him, he dissolved them in Aqua Regia and put unremarkable bottle away on the shelf, where it remained many bottles of bubbles with different liquids. Returning after the war in his laboratory, Boron primarily found precious bottle. At his request, the staff was isolated from the solution of gold and re-made both medals.(read more here)