Formula of aqua regia in chemistry. What is the composition of the acid “regia vodka”

home Ancient alchemists called gold the “king of metals.” Ordinary acids do not act on gold, so when an acid was discovered that could dissolve this noble metal, alchemists called it “regia vodka” ( Aqua regia

- it is more correct to translate from Latin as “royal water”). Aqua regia can dissolve not only gold, but also platinum. What is aqua regia? This is a mixture of two acids - hydrochloric and nitric in a ratio of 3:1 (three parts by volume of hydrochloric acid to 1 part by volume of nitric acid). Tsar vodka - liquid yellow color

, having the smell of chlorine and nitrogen oxides.

Aqua regia was first obtained by the Italian alchemist Bonaventura in 1270. It is curious that at that time hydrochloric acid was not yet known to science. Aqua regia was then prepared by distilling a mixture of saltpeter, copper sulfate and alum with the addition of ammonia.

The oxidizing properties of aqua regia disappear during storage because chlorine evaporates from it in air, and it is this that is the main one in oxidation reactions. Therefore, only freshly prepared reagent is suitable for work.

How does aqua regia act on noble metals?

First, nitric acid reacts with hydrochloric acid. In this case, two strong oxidizing agents are formed - nitrosyl chloride and chlorine:

HNO 3 + 3HCl = NOCl + Cl 2 + 2H 2 O.

These two reagents, when paired, are able to oxidize gold even at room temperature:

Au + NOCl 2 + Cl 2 = AuCl 3 + NO.

The resulting gold chloride AuCl 3 immediately adds another molecule of hydrochloric acid HCl, forming tetrachloroauric acid (known as “gold chloride”):

AuCl 3 + HCl = H].

The total reaction of gold oxidation with aqua regia looks like this:

Au + 4HCl + HNO 3 = H + NO + 2H 2 O. Tetrachlorauric acid crystallizes with four water molecules: H(AuCl 4) 4H 2 O. Its crystals are light yellow, water solution

also colored yellowish.

The reaction with platinum proceeds similarly with the formation of chloroplatinic acid H2:

It is very simple to obtain pure gold from tetrachloroauric acid hydrate: you need to heat it. When heated, “gold chloride” decomposes to release HCl and reddish-brown crystals of gold (III) chloride AuCl 3 . If you treat a solution of gold(III) chloride with caustic alkali NaOH, yellow-brown gold(III) hydroxide Au(OH)3 precipitates, which when heated turns into gold oxide Au2O3. And gold oxide decomposes at temperatures above 220°: 2Au 2 O 3 = 4Au + 3O 2.

By the way...

Gold, in addition to aqua regia, also dissolves in hot concentrated selenic acid:

2Au + 6H 2 SeO 4 = Au 2 (SeO 4) 3 + 3H 2 SeO 3 + 3H 2 O.

The unique properties of aqua regia were used by the famous Danish physicist laureate during the Second World War Nobel Prize Niels Bohr. In 1943, fleeing the Nazi occupiers, he was forced to leave Copenhagen. But he kept two gold Nobel medals of his colleagues - German anti-fascist physicists James Frank and Max von Laue (Bohr's own medal was taken from Denmark earlier). Not risking taking the medals with him, the scientist dissolved them in aqua regia and placed the unremarkable bottle further away on a shelf where many similar bottles and vials with various liquids were gathering dust. Returning to his laboratory after the war, Bohr first of all found a precious bottle. At his request, the staff isolated the gold from the solution and re-made both medals.

Often there is a need to purify gold from other metals contained in the alloy or scrap. When obtaining gold by cyanidation, dissolving ore in a solution of potassium cyanide, gold is also often mixed with silver and copper in the final product.

If it is necessary to turn low-grade gold into high-grade gold, the same task arises - to clean the precious metal from accompanying impurities. A classic method that allows for fairly simple cleaning is dissolving gold in aqua regia.

Dissolving gold

Homemade mixture

Aqua regia, or Aqua Regia, is a mixture of concentrated nitric and hydrochloric acids in a ratio of 1:3 by volume and approximately 1:2 by weight. More precisely, 65-68% by weight nitric acid (HNO3) and 32-35% hydrochloric acid (HCl). Such a strange name for this mixture was given by alchemists: only this “vodka” had the ability to dissolve the “king of metals” - gold (the very word “vodka” in Russian scientific language denoted chemical “water” - a liquid reagent; This term was assigned to a strong alcoholic drink much later).

As a result of the reaction of metallic gold with aqua regia, a complex compound is formed - chloroauric acid, or hydrogen tetrachloraurate. The following reaction occurs:

Au + HNO3 + 4 HCl = HAuCl4 + NO + 2 H2O.

Based on this chemical equation and the density of aqua regia, it turns out that to dissolve 1 gram of gold you need at least 5 ml of reagent. In this case, gold actually dissolves only in hydrochloric acid. Neither nitrogen nor oxygen is included in the composition of chloroauric acid. Nitric acid acts only as an oxidizing agent that catalyzes the entry of gold into the reaction. In this regard, it is better to carry out the dissolution process as follows.

First of all, if we are dealing with scrap containing gold, we need to remove ferromagnetic particles using a magnet. After this, purify the gold as much as possible from impurities using other acids, primarily pure nitric acid. Only then can the process of dissolving the gold begin.

First you need to measure out 3.75 ml of hydrochloric acid for each gram of gold-containing metal and fill it with it alone. If a more or less noticeable reaction begins, it means that some impurities have already begun to dissolve. You need to wait until the process is completed, drain the solution and pour a new portion of hydrochloric acid into the metal. Now you need to start heating the container with the reagent, gradually adding nitric acid at the rate of 1.25 ml per 1 gram of metal.

The main thing is not to overdo it with nitric acid, since when gold is precipitated from solution, it will be necessary to get rid of it most consistently. As soon as all the metal has dissolved, you should immediately stop adding it to the solution. Moreover, not all of the original substance will necessarily dissolve: silver, unlike gold, is passivated in aqua regia due to the formation of a dense chloride film on the surface. After dissolution is complete, keep the solution heated for about half an hour.

Filtering the solution

Now it's time to filter the solution. For now, you can use a fairly coarse filter, and finer cleaning will happen later.

The resulting precipitate

It should be understood that aqua regia itself is a rather unstable substance: hydrochloric and nitric acids react with each other. Initially transparent, it soon turns orange-brownish due to nitrogen oxides, and then completely loses its oxidizing properties. The following reactions occur:

HNO3 + 3 HCl = 2Cl + NOCl + 2H2O

In addition, both acids simply evaporate. In this regard, it is advisable to keep the solution for about a day at this stage, as this will facilitate the further process of evaporation of nitric acid.

When evaporating, a small amount of sulfuric acid should be added to the solution, no more than 50 ml per liter. This will help precipitate residual amounts of lead and silver chloride (which, although slightly soluble, may be present in small quantities in the solution). In addition, the evaporation process will go faster.

Heating is done slowly and carefully. The solution is evaporated to the consistency of syrup (no more!). It is impossible to bring it to a boil, since in this case it cannot be ruled out that gold will precipitate in the form of a metallic precipitate already at this stage.

Then add hydrochloric acid to the solution to the original volume and evaporate again to a syrupy state. The process is repeated three times. After this, the liquid is diluted 2 times cold water and left in the cold for a day. In this case, the remaining silver chloride should precipitate: it dissolves only in concentrated hydrochloric acid, and the higher the temperature, the better. Accordingly, as the concentration and temperature drop, AgCl precipitates. Now filtering is carried out “by full program": no turbidity should remain in the solution.

It is a mixture of acids of high concentration, and therefore a strong poison. The effect of this mixture on human body It’s scary to even imagine - after all, aqua regia can dissolve metals! It usually consists of one part hydrochloric acid (HCl) and three parts nitric acid (HNO3). It is also acceptable to add there sulfuric acid(H2SO4). Aqua regia looks like a yellow liquid, from which it emanates far from nice smell chlorine and nitrogen oxides.

Aqua regia is remarkable in that it dissolves almost all metals, even such as gold and platinum, but the metals do not dissolve in any of the acids that make up its composition. Active substances capable of dissolving metals are created from a mixture of acids during complex chemical reactions. However, there are metals that aqua regia cannot handle: rhodium, iridium and tantalum. PTFE and some plastics also do not dissolve in aqua regia.

History of creation and names

Aqua regia was created thanks to the research of alchemists, tireless in their search for the legendary “philosopher’s stone,” which was supposed to turn any substance into gold. They called gold the “king of metals”; accordingly, the liquid capable of dissolving it was called the “king of waters” (in Latin - aqua regia). But Russian alchemists translated this name into their native language in a somewhat unique way - in their mouths, the “king of waters” became “royal vodka”.

Alchemists learned to prepare aqua regia even before it was discovered. In those days, to make this composition, they used distillation of a mixture of saltpeter, alum and copper sulfate, also adding there.

Using aqua regia

Today, when no one is looking for the philosopher's stone anymore, aqua regia is used as a reagent in chemical laboratories - for example, in the refining of gold and platinum. But most often, chemists need aqua regia as a reagent for producing chlorides of various metals. Amateurs use aqua regia to extract gold from.

It is important to remember that aqua regia retains its properties only if it contains chlorine, which, if the vessel with the substance is left open, will quickly evaporate. At long-term storage In aqua regia, the chlorine also gradually disappears, and the liquid stops dissolving metals.

Royal vodka that you can drink

There is a cocktail of the same name, which can be prepared according to the following recipe:

60 ml regular vodka;
- 10 ml of white dessert vermouth;
- 10 ml orange tincture;
- 10 ml pepper tincture;
- ice in .

Mix all the ingredients and serve in a glass with ice, but this composition, of course, will no longer dissolve the gold.

Aqua regia is a mixture of hydrochloric and nitric acids. It has a strong oxidizing ability, so it can even dissolve gold. Hence its name - since this acid corrodes the “king of metals” - gold, then the name was also “royal”.

You will need

• Nitric acid;
• Hydrochloric acid;
• Glass test tube for mixing acids with markings;
• Glass rod.

Instructions

Since it is best to avoid using additional containers to measure the required amount of liquid, it is better to immediately add the acids to one test tube. The more you pour acid from one container to another, the greater the chance of spilling it.

Accordingly, you need to first pour into the test tube required quantity hydrochloric acid, since its production requires more volume than nitric acid, and when mixing dangerous ones, it is recommended to add less to more to avoid acid splashes and reduce the risk of burns.

"Bolotov's balm" is used as a prophylactic agent that improves immunity and helps reduce risk various diseases, prevents stroke and heart attack. "Bolotov's Balm" promotes overall rejuvenation of the body. Helps with gastrointestinal diseases, heartburn, herpes, hemorrhoids, cancer and AIDS.

Aqua regia should be consumed immediately after sleep, because... it neutralizes harmful substances, which accumulate in the human body during sleep. After taking it you will feel invigorated.

Bolotov's aqua regia (“Bolotov’s Balm”) should be consumed:


1. To stimulate the formation of gastric juice enzymes (pepsins).

2. To normalize decreased secretion of gastric juice.

3. To normalize zero acidity of gastric juice.

4. To thin the blood in the circulatory system.

5. To neutralize high blood sugar and cleanse blood vessels from fatty acid salts.

6. To rejuvenate the body, due to an increase in the percentage of young cells.

7. For the breakdown of old and diseased cells, cells of pathogenic organisms.

8. To normalize the body when it is alkalized due to the predominant intake of plant products that are highly alkaline and harmful.

9. For the treatment of heartburn, gastritis, stomach ulcers, hemorrhoids, herpes and other things.

10. To normalize the functioning of the entire gastrointestinal tract.

11. To increase the body's immunity (when creating mucopolysaccharides).

12. To break down plaques in blood vessels.

13. To prevent stroke, heart attack, arrhythmia, and vascular atherosclerosis.

14. To normalize the non-closing and weakened pylorus of the duodenum.

15. To neutralize free radicals.

This unique drink is involved in the breakdown of cells damaged by nitrates, radionuclides, free radicals, carcinogens, and various poisonous salts of heavy metals. It splits all kinds cancer cells, the protoplasm of which is weakened by the intake of the amino acid TRYPTOPHAN.

Preparation: You need to take 3 liter jar and fill it out clean water, leaving space in the jar for the following ingredients, which must be added and mixed thoroughly in the following sequence: 300 ml of grape vinegar (6% concentration), 3-6 teaspoons of sulfuric acid (98%), 3-6 teaspoons of hydrochloric acid (36 %), 12 nitroglycerin tablets.

Attention: Follow the sequence of adding the ingredients of aqua regia and after adding each component, thoroughly stir the resulting solution.

Reception: Take 1 teaspoon to 2 tablespoons 3-4 times a day before meals or as part of any drink immediately after meals, such as tea or coffee. It is best not to drink between doses. You should also drink the drink immediately after sleep.

Maximum dosage - 2 tbsp. spoons 4 times a day.

The preparation of aqua regia by mixing concentrated hydrochloric and nitric acids was first described in Alchemy by Andreas Libavius ​​(1597). For 1 liter of Tsarskaya vodka you can pay from 1000 rubles or more. Aqua regia is a mixture of hydrochloric and nitric acids.

The mixture is prepared immediately before its use: during storage it decomposes with the formation of gaseous products (the formation of nitrogen dioxide and nitrosyl chloride gives the aqua regia its color). Rhodium and iridium are stable in a compact state, but dissolve when heated in the form of highly dispersed powders (black).

Aqua regia is a clear liquid when freshly prepared.

Today, almost any person when asked: “What is aqua regia?” will answer with confidence that it is alcoholic drink. The name aqua regia is used both as a chemical term and as the name of a well-known alcohol.

But after the resulting mixture was able to dissolve the element of gold, which until then was considered indestructible, aqua regia received its official name from the translation of the words “aqua regia”. Aqua regia is an acid, which is a mixture of two concentrated acids, and, accordingly, it is strictly prohibited to consume it internally.

To do this you will need: concentrated nitric and hydrochloric acids, a glass test tube with marks, a glass rod. Today, aqua regia is used as a reagent, as well as for the sterility of glass instruments in laboratories and in the analysis of alloys.

Most people have heard of aqua regia as an alcoholic drink.

The aqua regia must be very carefully heated to 60-70 degrees and the alloy must be immersed in this mixture. The metal alloy must be pre-cleaned to prevent contamination. In fact, there are not one, or even two, but many recipes for this vodka.

To obtain aqua regia, you need to mix one part nitric acid and three parts hydrochloric acid.

It contains: drinking water, ethyl grain alcohol, linden honey and tincture. Vodka of this brand is considered a drink upper class and is sold in expensive frosted glass bottles with decoration. The composition of royal vodka was developed based on recipes for alcohol served to the table of the imperial Romanov dynasty. Vodka “Tsarskaya” is produced in several series.

In addition to the main ingredients, it contains a tincture of bird cherry berries and raspberry leaves. Luxuriously designed packaging with a bottle of Imperial Collection vodka includes only water, luxury alcohol and aromatic alcohol. All four types are also available in beautiful gift boxes. Dr. Bolotov also advises taking the drink only for the purposes of treatment and cleansing the body.

A volume of 1.5 and 2 liters costs about 1500-2000 rubles. Homemade vodka is usually not sold, since the ingredients for it are quite easy to find, and the recipe is simple and does not require complex steps. You can buy Tsarskaya vodka online and in any store in your city. Today, vodka is a popular product. And vodka of good quality and in beautiful packaging should be on the shelves of all stores.

Aqua regia from acids can be purchased in stores specializing in industrial chemicals. There are not many of them, but you can find them on the Internet. Royal vodka homemade It’s hard not to praise, especially if you did it yourself. But it’s difficult to form a definite opinion about purchased vodka bottled at the factory.

The quality and beautiful execution of Tsarskaya vodka provide it with buyers and positive reviews. The oxidizing properties of aqua regia disappear during storage because chlorine evaporates from it in air, and it is this that is the main one in oxidation reactions. Thus the name aqua regia (also aqua regis, A.R.) appeared.

Establishing the fact of dissolution noble metals in aqua regia was considered by alchemists as a solution to one of most important tasks alchemy: preparation of alkahest - a universal solvent. Aqua regia can dissolve not only gold, but also platinum. How does aqua regia act on noble metals?

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Aqua regia: what does it consist of?

Aqua regia is a mixture of highly concentrated acids, and therefore a powerful poison. The effect of this mixture on the human body is scary to even imagine - after all, aqua regia is capable of dissolving metals! It usually consists of one part hydrochloric acid (HCl) and three parts nitric acid (HNO3). It is also permissible to add sulfuric acid (H2SO4) there. Aqua regia looks like a yellow liquid, which emits a far from pleasant smell of chlorine and nitrogen oxides.

Aqua regia is remarkable in that it dissolves almost all metals, even such as gold and platinum, but the metals do not dissolve in any of the acids that make up its composition. Active substances capable of dissolving metals are created from a mixture of acids during complex chemical reactions. However, there are metals that aqua regia cannot handle: rhodium, iridium and tantalum. PTFE and some plastics also do not dissolve in aqua regia.

History of creation and names

Aqua regia was created thanks to the research of alchemists, tireless in their search for the legendary “philosopher’s stone,” which was supposed to turn any substance into gold. They called gold the “king of metals”; accordingly, the liquid capable of dissolving it was called the “king of waters” (in Latin - aqua regia). But Russian alchemists translated this name into their native language in a somewhat unique way - in their mouths, the “king of waters” became “royal vodka.”

Alchemists learned to prepare aqua regia even before hydrochloric acid was discovered. In those days, to make this composition, they used distillation of a mixture of saltpeter, alum and copper sulfate, also adding ammonia.

Using aqua regia

Today, when no one is looking for the philosopher's stone anymore, aqua regia is used as a reagent in chemical laboratories - for example, in the refining of gold and platinum. But most often, chemists need aqua regia as a reagent for producing chlorides of various metals. Hobbyists use aqua regia to extract gold from radio components.

It is important to remember that aqua regia retains its properties only if it contains chlorine, which, if the vessel with the substance is left open, will quickly evaporate. When storing aqua regia for a long time, the chlorine also gradually disappears, and the liquid stops dissolving metals.

Royal vodka that you can drink

There is a cocktail of the same name, which can be prepared according to the following recipe:

— 60 ml of regular vodka;
- 10 ml of white dessert vermouth;
- 10 ml orange tincture;
- 10 ml pepper tincture;
- ice in cubes.

Mix all the ingredients and serve in a glass with ice, but this composition, of course, will no longer dissolve the gold.

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Story

Aqua regia was first described by Pseudo-Geber. He was an unknown alchemist. His treatises circulated in Europe in the fourteenth century. Long before the discovery of hydrochloric acid, it was described in Latin works chemical formula royal vodka This liquid was obtained by dry sublimation of a mixture of alum, saltpeter, copper sulfate and ammonia in a glass smeared vessel. The container was equipped with a cap or glass lid.

Albert the Great in his writings calls aqua regia aqua secunda. This name means "secondary vodka". Aqua prima is translated as “primary vodka,” which means nitric acid. Some alchemists call the formula for vodka aqua regia.

Bonaventure in 1270 made public his own method of obtaining the miracle liquid: he liquefied ammonia in “strong vodka” (aqua fortis, nitric acid). Bonaventure was able to establish that nitric acid could dissolve silver, detaching it from gold. He determined that “regia vodka” is capable of dissolving the “king of metals” - gold. But until some time it was believed that this substance cannot be subjected to changes.

Thus, the name aqua regia appeared. Aqua regia began to be designated by an alchemical symbol made up of the sign of water and the letter “R”.

Aqua regia and alchemy

In the alchemy of Andreas Liebavius ​​in 1597, the production of aqua regia by mixing saturated hydrochloric and nitric acids was first described. Alkahest is a universal solvent. Its preparation was considered as a solution to one of the most important problems of alchemy.

Aqua regia was used quite often in the practice of alchemy. This has led to a significant increase in knowledge about chemical reactions and substances. In addition, such experiments contributed to the development of technical chemistry and assay analysis.

In Lavoisier’s works, the formula for vodka “royal” was called nitromuric acid. Scientists thought that the chlorine released in a gaseous state was an oxide of the element muria or dephlogisticated hydrochloric acid.

In Russia she had many names. In the works of M.V. Lomonosov for 1742 it is called “royal vodka”. M. Parpois in 1796 called it “royal vodka”. V.V. Petrov in 1801 gave it the name saltpeter-hydrochloric acid, and G.I. Hess named it nitric-hydrochloric acid in 1831. Other names for this liquid are also common.

The word “vodka” appeared in Russian in the fourteenth century. It was a diminutive of the word “water” and had given value until the mid-nineteenth century. Later this word acquired the meaning “ alcoholic drink", at first it was dialectal. It was only at the beginning of the twentieth century that vodka began to mean strong alcohol.

Properties

Aqua regia has a yellow-orange color with a strong odor of nitrogen dioxide and chlorine. The freshly prepared liquid is colorless, but quickly turns orange.

What is aqua regia made from? Its formula is quite interesting. When HNO3 and HCI interact, a complex mixture of products with high activity, including associates and free radicals. This liquid is one of the most powerful oxidizing agents. The mixture is prepared immediately before use, since during storage it disintegrates and loses its oxidizing qualities:

3HCl+HNO3=2Cl+NOCl+2H2O

The effectiveness of aqua regia as an oxidizing agent is largely due to a decrease in the possibility of metal oxidation. This occurs due to the formation of complex chloride compounds. Complexation in an oxidizing, strongly acidic environment makes it possible to liquefy low-activity metals such as platinum, gold and palladium already at room temperature.

Application

This liquid is used as a reagent in chemical laboratories. It is used to cleanse glassware from traces of organic matter. Aqua regia is used in assay analyzes of high-grade metals and their alloys, in the refining of platinum and gold, in the production of metal chlorides, and so on.

Vodka

Vodka is a colorless alcoholic drink. It is an aqueous-alcoholic liquid without obvious odor or taste. The strength of vodka can be completely different: according to Russian standards - 40-45% and 50-56% by volume, according to EU legislation - at least 37.5%.

The classic formula of vodka is quite interesting - C2H5OH 40% + H2O 60%. The process of producing this liquid consists of preparing reclaimed water and mixing rectified ethyl alcohol extracted from food raw materials with reconstituted water. The water-alcohol mixture is treated with modified starch or activated carbon. Then it is filtered, the ingredients are added, mixed, filtered again and poured into consumer containers. Finished products formatted accordingly.

No less interesting is the chemical formula of vodka with a strength of 40.0 - 45.0% with a special aroma and taste. Such a liquid is called special. It is produced by adding various ingredients, flavoring and aromatic additives.

With excessive and regular use, vodka causes alcohol dependence and addiction.

Mendeleev

In Russia there are many legends about “gorka”. One of the myths points to the connection between the appearance of vodka and the activities of D.I. Mendeleev. The basis was his doctoral dissertation, which was called “On the combination of alcohol with water.”

Oh, this formula for Mendeleev’s vodka! What is she really like? The myth tells the following:

• While doing his dissertation, the scientist established the unusual properties of an aqueous-alcoholic liquid. The mixture had an ethanol concentration of 43% by volume and had a strange effect on a living organism.
• With a similar concentration, an aqueous-alcoholic liquid can be obtained only by mixing parts by weight of alcohol and water.
• Based on these facts, Mendeleev was able to develop a recipe called “Moscow Special”. This exclusive was patented in 1894 Russian government like national Russian vodka.

Of course, D.I. Mendeleev never took part in the creation or modernization of vodka. Only a few of his works were subsequently used to make this liquid.

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History of royal vodka

The turning point in the development of chemistry was the 13th century, when alchemists discovered strong mineral acids capable of dissolving many water-insoluble substances. Before this, the world knew only about acetic acid, known since ancient times. The newly discovered acids turned out to be a million times stronger, which brought alchemy to a new frontier, because it became possible to produce many chemical processes and reactions. So nitric acid was soon discovered, called “aqua fortis” - strong water, corroding everything that came into contact with it, with the exception of gold, all metals known at that time. Three centuries later, hydrogen chloride (hydrochloric acid) was discovered.

In 1597, alchemist Andreas Libavia first described the preparation of aqua regia by mixing a concentrate of nitric and hydrochloric acid. Before this, there were attempts to obtain alkahest by dry distilling a mixture of saltpeter, ammonia, copper sulfate and alum in a glass vessel and covering it with a lid or cap. This method was described in the 14th century by the alchemist Pseudo-Geber, but it was very painstaking and complex, and besides, such a mixture could cope with silver, but gold was beyond his control. And in the 16th century, a universal solvent was finally found and the invention of “aqua regia” contributed to the development of technical chemistry and the improvement of assay analysis.

What acids does aqua regia consist of?

As for the composition of aqua regia, it turned out that the chemical mixture of hydrochloric and nitric acid, when interacting with its components, enhances its abilities several times. The mixture turned out to be so strong that gold and even platinum dissolve in it at a ratio of 1:4 (hydrochloric acid, when reacting with nitric acid, releases chlorine, and the solution turns green, and particles of free chlorine attack gold).

The interaction formula looks like this:
Nitric acid oxidizes hydrochloric acid
HNO3 + 3HCl = NOCl + Cl2 + 2H2O.
During this process, two active substances appear: nitrosyl chloride and chlorine, which are able to dissolve gold:
Au + NOCl2 + Cl2 = AuCl3 + NO.

Gold chloride instantly attaches a HCl molecule to itself, resulting in the formation of tetrachloroauric acid, also popularly known as “gold chloride”: AuCl3 + HCl = H (AuCl4).

Preparation of aqua regia at home should be carried out in compliance with all safety measures and in a well-ventilated area.
To prepare aqua regia, you will need to acquire two main ingredients: concentrated hydrochloric and nitric acid.
We also strongly recommend using only glass test tubes (with marks) and a glass rod for uniform stirring " explosive mixture" The original composition is a mixture of two acids in a quantitative ratio of 1: 3. Mix using only one test tube, do not measure acids in other containers, this way you minimize the chance of acid spillage.
Now you need to discuss separately those components that you will have to deal with when making aqua regia.

Nitric acid

Monoprotic acid, sensitive to light, has a very pungent suffocating odor. Nitric acid will decompose into nitric oxide and water under strong light. In this regard, one of the strongest acids is stored in a dark or opaque container. A concentrated solution of nitric acid does not dissolve aluminum and iron, so it can be safely stored in a metal container.

I would like to note that nitric acid is a very strong electrolyte (like most acids) and an oxidizing agent. Very interesting fact, is that nitric acid (like ozone) can be formed in the atmosphere during strong lightning flashes. Compound atmospheric air consists of 78% Nitrogen, which reacts with atmospheric oxygen. This reaction produces nitric oxide (NO). Subsequently, with further oxidation in open air, nitrogen oxide is converted into nitrogen dioxide (NO2 or as it is also called brown gas). When atmospheric moisture reacts with nitrogen dioxide, nitric acid is produced. The concentration in such cases is minimal, and it is not at all dangerous for people, animals and nature.

Hydrochloric acid

The second component of aqua regia is hydrochloric acid. This acid is colorless, in the open air it emits steam in the form of “smoke”, a very caustic liquid (hydrochloric acid of technical significance may have a yellowish tint due to the presence of iron and chlorine impurities in it).

When we're talking about O physical properties hydrochloric acid, it should be noted here strong point when all metals (which are in the voltage series up to hydrogen) are dissolved, H2 is released and chloride salts are formed). You need to be very careful when using this acid, carry out work or experiments outdoors or in a well-ventilated area, since the acid is very Strong smell and severely irritates the mucous membranes of the upper respiratory tract human body.

The production of hydrochloric acid occurs by dissolving hydrogen chloride gas in ordinary water(H2O). In turn, hydrogen chloride can be obtained by reacting sodium chloride with highly concentrated sulfuric acid.

Uses of aqua regia

Many Soviet and post-Soviet families knew the composition of royal vodka by heart. People use it to dissolve gold at home, in order to extract pure gold from microcircuits, transistors, wristwatches and other unnecessary devices that contain a small amount of gold.

The main aspect of the successful completion of your planned chemical experiment with aqua regia is safety. Use personal protective equipment, follow safety rules, be extremely vigilant and attentive, your life and health will be at stake.