What is the composition of Bertolet salt. Bertolet salt: chemical properties, preparation and application Bertolet salt is used in the production of matches

Introduction

Studying oxygen in chemistry, you have reached the section "Producing oxygen in the laboratory by the decomposition of inorganic substances." "The decomposition of water, potassium permanganate, hydrogen peroxide, heavy oxides and nitrates of active metals ... so, everything seems to be clear. Obtaining oxygen from bartholium salt? What kind of animal is this ?!" - the standard train of thought of every student looking through this paragraph in the textbook. Bertolet salt is not taught at school, so you have to make inquiries about it yourself. Today in this article I will try to answer the question of what Bertolet's salt is in as much detail as possible.

origin of name

First, let's talk about its name. Salt is a separate class of inorganic substances, in the chemical formula of which there is such an arrangement of elements: Me-n- acidic residue, where Me is a metal, acidic residue is an acid residue, n is the number of atoms (may not be present if the valency of the metal and acid residue is the same). The acid residue is taken from some inorganic acid. The chemical formula of this salt is KClO 3 . The metal that is present in it is potassium, which means that it is potassium. The source of the ClO 3 residue is chloric acid HClO 3 . In summary, Berthollet salt is the potassium salt of chloric acid. It is also called potassium chlorate, and the adjective "bertoletova" is attributed to it because of the name of its discoverer.

Discovery history

It was first obtained in 1786 by the French chemist Claude Berthollet. He passed chlorine through a hot concentrated solution of potassium hydroxide (photo).

Bertoletova salt: obtaining

The production of chlorates by industrial means (including bertolet salt) is based on the reaction of disproportionation of hypochlorites, which are obtained by the interaction of chlorine with alkali solutions. The design of the process can be different: due to the fact that the most large-tonnage product is calcium hypochlorite, which makes up bleach, the most common process is the exchange reaction between calcium chlorate (it is obtained by heating calcium hypochlorite) and potassium chloride (it crystallizes from the mother solution). Potassium chlorate can also be obtained thanks to the modified Berthollet method by non-diaphragm electrolysis of potassium chloride. The resulting chlorine and potassium hydroxide immediately interact. The product of their reaction is potassium hypochlorite, which further disproportionates to the original potassium chloride and potassium chlorate.

Chemical properties

If the heating temperature reaches 400 ° C, the decomposition of the Berthollet salt occurs, in which oxygen is released and potassium perchlorate is intermediately formed. With catalysts (manganese oxide (4), iron oxide (3), copper oxide, etc.), the temperature at which this process occurs becomes much lower. Bertolet's salt and ammonium sulfate can react in a water-alcohol solution and form ammonium chlorate.

Application

Mixtures of reducing agents (phosphorus, sulfur, organic compounds) and potassium chlorate are explosive and sensitive to shock and friction (photo above). Sensitivity increases if bromates and ammonium salts are present. Due to the high sensitivity of the compositions in which Bertolet salt is present, they are almost never used in the production of military and industrial explosives. It is sometimes used in pyrotechnics as a source of chlorine for colored flame formulations.

It is also found in match heads and very rarely can be an initiating explosive (chlorate powder detonated the cord and was the grating composition of Wehrmacht hand grenades). Yes, and in the USSR, potassium chlorate is part of the fuse of the Molotov cocktail, prepared according to a special recipe. Berthollet salt solutions used to be sometimes used as a weak antiseptic, external medicine for gargling. At the beginning of the 20th century, Bertolet's salt was used to produce oxygen in the laboratory. However, due to the high risk, it was no longer used. Also, with the help of it, chlorine dioxide is obtained in laboratory conditions (there is a reduction reaction of potassium oxalic chlorate and sulfuric acid is added).

Conclusion

Now you know everything about Bertolet's salt. It can be both useful and extremely dangerous for a person. If you have matches at home, then every day you observe one of the branches of the use of berthollet salt in everyday life.

The scientific name of Bertolet salt is potassium chlorate. This substance has the formula KClO3. Potassium chlorate was first obtained by the French chemist Claude Louis Berthollet in 1786. Berthollet decided to pass chlorine into a heated solution. When the solution cooled, crystals of potassium chlorate fell to the bottom of the flask.

potassium chlorate

Bertolet's salt is a colorless crystal that decomposes when heated. First, potassium chlorate decomposes into perchlorate and potassium chloride, and with stronger heating, potassium perchlorate decomposes into potassium chloride and oxygen.

It is noteworthy that the addition of catalysts (oxides of manganese, copper, iron) to Bertolet salt reduces the temperature of its decomposition by several times.

The use of Berthollet salt

Another industrial method for obtaining Bertolet salt is the electrolysis of aqueous solutions of potassium chloride. A mixture of potassium hydroxide and chlorine is first formed on the electrodes, then potassium hypochlorite is formed from them, from which, in the end, Bertolet's salt is obtained.

Claude Berthollet

The inventor of potassium chlorate, Claude Berthollet, was a physician and apothecary. In his free time, he was engaged in chemical experiments. Claude achieved great scientific success - in 1794 he was made a professor at two higher Parisian schools.

Berthollet was the first chemist who managed to establish the composition of ammonia, hydrogen sulfide, swamp gas and hydrocyanic acid. He invented silver fulminate and the chlorine bleaching process.

Later, Berthollet dealt with issues of national defense and served as an adviser to Napoleon. At the end of his service, Claude founded a scientific circle, which included such famous French scientists as Gay-Lussac, Laplace and Humboldt.

Bertoletova salt with his own hands.

This note will be of interest to those readers who want to make or get bartolet salt on their own at home. There is nothing difficult in this procedure, except that it is necessary to strictly follow the instructions of the instructions.
Materials needed for self-preparation of salt
Before preparing the desired product, you need to prepare everything necessary for its production at home. Here is a list of required components:
1) ten boxes of matches, it is recommended to use Plitspichprom matches, as they are the most suitable in terms of their components;
2) one Petri dish, or another chemical flask, or, in extreme cases, an unnecessary glass and saucer, which later it will not be a pity to throw it in the trash;
3) a ball of thread and a thin elastic band;
4) acetone.
Step-by-step instructions for making this salt
We take out all the matches from the boxes, neatly and evenly fold them with their heads in one direction, and then we tighten them tightly with threads or put an elastic band on them, it doesn’t matter, as long as the matches hold tightly together. We lower the resulting bunch of matches with the sulfur side into a glass and drown in a liquid at a temperature close to one hundred degrees, so much so that the matches are completely under water. This is approximately seven centimeters in height.
We put a glass with placed matches and hot water in some kind of warm corner for a period of time up to four hours. After the elapsed time, pour the water from the glass into a Petri dish. And then we apply one of the two methods, which one we liked and approached more.
First method
It is necessary to let the invented solution stand for a while, allowing it to evaporate a little, but our potassium chlorate crystals have not yet begun to form. Then we slightly impregnate this liquid with acetone so that it turns pale in the cup, and then again we give the solution a little time to stand. After some time, you will see that the solution has acquired a yellow tint, hide it in a cold place until colorless crystals begin to form in the solution, which are our long-awaited substance. Take them out gradually and let them dry.
Second method
The following method involves the extraction of a large amount of salt with one's own hands at home. It is necessary to pour the liquid into a Petri dish for drying and wait for the required amount of dried substance to appear, fill it with H2O and then proceed according to the principle of the first method.
If you use a dozen boxes of matches, you get 9.5 g of ready-made bartholium salt. Try it and you will definitely succeed.