nine wholesale jewelry Chemical problem

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nine wholesale jewelry Which substances can dissolve platinum and gold?

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  1. Willard

    wholesale aquamarine jewelry Aqua Regia, also known as "king acid", is a liquid with a very corrosive and yellow smoke. It is a mixture composed of nitric acid (HNO3) and hydrochloric acid (HCL). It can be seen: Wang, one vertical three horizontal, one is 1: 3, or a few substances that can dissolve AU and PT. This is also the source of its name. However, the king of plastics -polytefluorolytin and some very inert metals such as TA are not corroded by the king water. Wang Shui is used in the etching process and some analysis. Wang Shui quickly decomposed, so it must be made directly before use.
    [Edit this paragraph] History
    The hydrochloric acid was found in about 800 years of Persian alchemy warlock Zabir Ibn Harbin Essence He mixed hydrochloric acid with nitric acid to invented the king water that can dissolve gold.
    [Edit this paragraph] Principles
    Although the two components of Wang Shui are single -unable to dissolve gold, they can unite to dissolve gold. The principle is: nitric acid is a very strong oxidant, which It can dissolve the extremely small amount of gold, while the hydrochloric acid can react with the gold ions in the solution to form chloride gold, so that the gold ion leaves the solution, so that nitric acid can further dissolve the gold:
    au no3- 4h → AU3 NO ↑ 2H2O
    AU3 3CL- → AUCL3
    AU HNO3 HCL══AUCL3 No ↑ 2H2O
    AUCL3 HCL══hauCl4 (tetrachlomolon acid)
    Δ
    2hauCl4══2HCl ↑ 3CL2 ↑ 2AU

    [Edit this paragraph] Wang Shui and its oxidation effect
    Mixed with nitric acid and 3 volume of concentrated hydrochloric acid (the ratio of the amount of material in HNO3 and HCL in its mixed acid is 1: 3). Wang Shui has a strong oxidation ability, known as the king of acid. Some metals with insoluble nitric acid, such as gold, platinum, can be dissolved by Wang Shui. Although two types of acid are taken when preparing the water, the concentration of nitric acid is obviously only 1/4 of the original concentration in its mixed acid (that is, it has become dilute nitric acid). But why is the oxidation ability of Wang Shui more stronger than concentrated nitric acid? This is because there is the following reaction in the water:
    hno3 3HCl ==== 2H2O CL2 NOCL
    So a series of strong oxidants such as nitric acid, chloro molecular and chloride nitride in the king water At the same time, there are high concentrations of chloride ions.
    The oxidation capacity of king water is stronger than nitric acid. Invasive metals such as gold and platinum are insoluble in a separate concentrated nitric acid, and can be dissolved in the king water. With stronger oxidation capabilities than concentrated nitric acid, it can make inert metals such as gold and platinum lose electrons and be oxidized:
    AU CL2 NOCL = AUCL3 No ↑
    3pt 4CL2 4NOCL = 3ptCl4 4NO ↑

    The high concentration of chloride ions with its metal ions can form a stable neutral ion, such as [AUCL4] - or [Pt CL6] 2 -:
    auCl3 HCL = H [AUCL4 ]
    PTCL4 2HCL = H2 [PT CL6]

    to reduce the standard electrode potential of gold or platinum, which is conducive to reaction to the direction of dissolving metal. The chemical equation of the total reaction can be expressed as:
    AU HNO3 4HCL = H [AUCL4] No ↑ 2H2O
    3pt 4HNO3 18HCl = 3H2 [PT CL6] 4NO ↑ 8H2O R

    Since gold and platinum can be dissolved in the king's water, people’s golden platinum jewelry (gold or platinum) is often cleaned by the processing of jewelry processing business. Damage to the interests of consumers.
    [Edit this paragraph] Anecdotes of Wang Shui and Nobel medals
    The two scientists, Laos and Frank, have won the 1914 and 1925 Physics Awards. The German Nazi government will confiscate them. The Nobel medal, they came to Denmark, asking Danish colleagues, and the 1922 Physics Award winner Bohr helped to save. In 1940, Nazi Germany occupied Denmark, and Bohr, who was entrusted by people, was anxious. A Hungarian chemist Hevisi (chemical winner in 1943) who worked in the laboratory helped him think of a good idea: put the medal into the "king water" (hydrochloric acid and nitric acid mixture), and the pure gold medal Solk. Bohr put the solution bottle on the laboratory frame, and the Nazi soldiers who were searched did not find this secret. After the war, the gold in the solution bottle was sent to Stockholm after being restored. It was re -cast according to the mold of the year. In 1949, it returned to Zhao. At that time, Chicago, USA, also held a grand medal return ceremony.
    This with Wang Shui "hand and feet" washing the necklace stealing gold
    The April 28, 2008 Inner Mongolia Autonomous Region Ordos City's Dongsheng District Public Security Branch Criminal Investigation Brigade cracked a special golden theft. The suspect was a The owner of the gold and silver jewelry processing store, the owner of the name Wu used the opportunity to clean the gold necklace to steal gold. After the theft was revealed, the stolen boss was taken by the police on April 18.
    It according to reports, on the afternoon of April 1, the Criminal Investigation Brigade of the Public Security Bureau of Dongsheng District received a report that his gold necklace was cleaned in a gold and silver jewelry processing store, and found that the gold necklace was not only thinner. And the pattern on the necklace becomes unclear. After he reached the gold necklace, he found that the original 78 grams of gold necklace was 16.48 grams.
    In after receiving the police, the police immediately rushed to the gold and silver jewelry processing store to bring the owner back to the question. According to analysis and testing, the original shop owner was cleaned with a very corrosive "Wang Shui" to clean the gold necklace in order to steal gold. In the face of the evidence, the owner of the surname of Wu explained that when the jewelry such as gold was cleaned, it was burned with fire first, and the gold was used to remove the oil on the top. And there is no loss for gold itself. But in order to make a profit, he replaced the cleaning solution with "Wang Shui", using chemical reactions to steal the customer's jewelry gold, the longer the soaking time, the more gold.
    The boss of Wu also explained that because the state has no uniform standards and regulations on jewelry cleaning at present, some small jewelry processing stores use low -priced cleaning as bait. After the customer comes to, use "Wang Shui" to wash the gold. The method has almost become an open secret in the industry, and the profits are considerable. In response to this special golden theft, the police reminded people who cleaned the gold jewelry to go to large -scale regular gold and silver jewelry stores with good business reputation for processing or use of jewelry cleaning and beauty. shop. //28042822/2008-04-28-14-48-01.asp

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