About 800 years ago, Persian alchemist Jabir Ibn Khayan mixed salt with alum (sulfuric acid) and discovered hydrochloric acid. He mixed hydrochloric acid with nitric acid and invented aqua regia which can dissolve gold.
Aqua regia has both oxidizing ability of nitric acid and strong coordination ability of chloride ion, so it can dissolve inert metals such as gold and platinum. The addition of concentrated hydrochloric acid did not enhance the oxidation of nitric acid, but enhanced the reduction ability of metals. Au (gold) is coordinated with HCl and HCl to form HAuCl4 tetrachloroalloy acid, which enhances the reducing ability of metal and makes it possible to oxidize gold with nitric acid.
1,1998 March case of the water-soluble corpse of Qing Wang in Taiwan Province Province, China.
2. On April 28th, 2008, the Criminal Investigation Brigade of Dongsheng District Public Security Bureau in Ordos City, Inner Mongolia Autonomous Region cracked a gold theft case. In order to steal gold, the shopkeeper specially cleaned the gold necklace with highly corrosive aqua regia. Shopkeepers explained that when cleaning gold and other jewelry, they usually burn it first to remove the oil stains on the gold, and then wash the scalded gold with hydrochloric acid solution, so that the dust on it is washed away and there is no loss to the gold itself. But he changed the cleaning solution to aqua regia and used chemical reaction to steal customers' jewelry gold. The longer he soaked, the more gold he stole.
3. Laue and Frank won the physics prizes of 19 14 and 1925. The Nazi government in Germany wanted to confiscate their Nobel Prize, so they moved to Denmark and asked their Danish counterparts, Bohr, the physics prize winner of 1922, to keep it for them. 1940, Nazi Germany occupied Denmark, and Hevesy, a Hungarian chemist who worked in the laboratory with Bohr (winner of the 1943 chemistry prize), helped him think of an idea: put the medal in "aqua regia" (a mixture of hydrochloric acid and nitric acid), and the pure gold medal would dissolve. Bohr then put the solution bottle on the shelf of the laboratory, and the Nazi soldiers who came to search did not find the secret. After the war, the gold in the solution bottle was reduced and sent to Stockholm, where it was recast with the same mold. 1949 When Zhao was returned, a grand medal return ceremony was held in Chicago, USA, where Frank worked at that time.
4. After The Golden Robbery was released, its plot was illogical and was questioned by many people. At the end of the film, Xiaodong pulls a tanker of aqua regia into the bank to dissolve gold, and the climax is repeated. However, Fang sent a Weibo in the early morning, indicating that this was a very retarded plot: "Aqua regia is a mixture of concentrated nitric acid and concentrated hydrochloric acid 1:3, which is very unstable and will release a lot of chlorine gas. It is all ready-to-use, cannot be transported and stored, and there is no finished product. If someone prepares a tank of aqua regia to dissolve gold, everyone around him will be poisoned by chlorine. Not to mention that the tanker must be dissolved first. "
Extended reading:
1.
What chemical is aqua regia?
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