Potassium nitrate called saltpeter. Rules for the use of potassium nitrate for indoor plants

The buildings 22.05.2019

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Structural formula

True, empirical, or gross formula: KNO 3

Chemical Composition of Potassium Nitrate

Molecular mass: 101.106

Potassium nitrate, potassium nitrate(potassium nitrate, potassium nitrate, Indian nitrate, etc.) is an inorganic compound, potassium salt of nitric acid with the formula KNO 3. In the crystalline state, it is a colorless, non-volatile, slightly hygroscopic, odorless substance. Potassium nitrate is highly soluble in water. Practically non-toxic to living organisms.
It occurs naturally in the form of the mineral nitrocalite, in the East Indies there is one of the largest deposits, hence the second name - Indian saltpeter. It is found in very small quantities in plants and animals.
The crystals are acicular, the crystals themselves are very long. Easy to clean by recrystallization with minimal loss.
It is mainly used in pyrotechnics (until the 20th century, it was especially widespread as a component of the main explosive at that time - black powder) and as a potassium-nitrogen fertilizer (a very convenient combination of two elements that are usually poorly combined when assimilated by plants).

Physical properties

Potassium nitrate normal conditions represents colorless crystals (white powder in a crushed state) with ionic structure and rhombic or hexagonal crystal lattice... Slightly hygroscopic, prone to caking slightly over time. Odorless, non-volatile. Let's well dissolve in water, moderately in glycerin, liquid ammonia, hydrazine, insoluble in pure ethanol and ether (it dissolves poorly in diluted water). Solubility table in some solvents, in grams of KNO 3 per 100 g of H 2 O:

Solvent / Temperature	0 ° C	10 ° C	20 ° C	25 ° C	30 ° C	40 ° C	60 ° C	80 ° C	100 ° C
Water	13,9	21,2	31,6	37,9	46,0	61,3	106,2	166,6	245,0
Liquid ammonia	10,52			10,4
Hydrazine			14
Diethyl ether
Ethanol
Methanol
Glycerol

On slow crystallization, very long needle-like crystals grow. Potassium nitrate lends itself well to purification by recrystallization, and with small losses, due to strong increase solubility with increasing temperature.

Chemical properties

Decomposes at 400-520 ° C with the formation of potassium nitrite KNO 2 and oxygen O 2 (the release of the latter increases the fire hazard of potassium nitrate):
2KNO 3 → 2KNO 2 + O 2
It is a strong oxidizing agent, reacts with combustible materials and reducing agents, actively and often explosively during grinding. Mixtures of potassium nitrate with some organic materials are prone to spontaneous combustion.
Reduced by hydrogen at the time of isolation (diluted hydrochloric acid in the reaction):
Zn + 2HCl → ZnCl 2 + 2H 0
KNO 3 + 2H 0 → KNO 2 + H 2 O
Potassium nitrate melt can be used to obtain potassium by electrolysis, however, due to the high oxidizing ability of potassium nitrate in this state, potassium hydroxide is preferable.

Receiving

In the Middle Ages and New Time (when gunpowder was actively used), saltpeter was used to obtain potassium nitrate - heaps of a mixture of manure (and other decaying components) with limestone, construction waste and other limestone material with interlayers of straw or brushwood, covered with turf to keep the resulting gases. When manure rotted, ammonia was formed, which, accumulating in layers of straw, was subjected to nitrification and turned first into nitrous and then into nitric acid. The latter, interacting with limestone, gave Ca (NO 3) 2, which was leached out with water. The addition of wood ash (consisting mainly of potash) precipitated CaCO 3 and produced a potassium nitrate solution; often ash was added immediately to the heap instead of limestone, then potassium nitrate was obtained immediately. The reaction of potash with calcium nitrate (calcium nitrate).
Ca (NO 3) 2 + K 2 CO 3 → 2KNO 3 + CaCO 3
is the oldest used by man to obtain potassium nitrate and is still popular. Instead of potash, however, now in laboratories, potassium sulfate is most often used, the reaction is very similar:
Ca (NO 3) 2 + K 2 SO 4 → KNO 3 + CaSO 4
The first method was used until 1854, when the German chemist K. Nöllner invented the production of potassium nitrate, based on the reaction of more affordable and cheaper potassium chloride and sodium nitrate:
KCl + NaNO 3 → KNO 3 + NaCl
There are several other ways to obtain potassium nitrate. This is the interaction of ammonium nitrate and potassium chloride with the formation of potassium nitrate and ammonium chloride, the latter being easily separated:
KCl + NH 4 NO 3 → KNO 3 + NH 4 Cl
KOH + HNO 3 → KNO 3 + ammonia by nitrobacteria, which is facilitated by moisture and heat, therefore the largest deposits are found in countries with hot climates.
It is found in very small quantities in plants and animals, it is an intermediate product in the processing of soil sulphate and potassium carbonate by them.

Application

The main application today is potassium nitrate as a valuable fertilizer, since it combines two elements that partially block the assimilation of each other by plants when they are included in separate compounds.
It is irreplaceable in the manufacture of black powder and some other compounds (for example, caramel rocket fuel), which are now almost entirely used for the production of pyrotechnics.
It is also used in the electrovacuum industry and optical glassmaking for discoloration and clarification of technical crystal glasses and for imparting strength to glass products.
The melt is often used in laboratories and among hobbyists to obtain elemental potassium by electrolysis, along with potassium hydroxide.
It is used as a strong oxidizing agent in metallurgy, in particular in the processing of nickel ores.
V Food Industry potassium nitrate is used as a preservative E252. By itself, it does not have a well-pronounced antibacterial effect, but it is formed in meat products (where potassium nitrate finds the most wide application) potassium nitrite.

Potassium nitrate is a binary compound of inorganic origin, the potassium salt of nitric acid. Other names for the substance - potassium nitrate, Indian nitrate, potassium nitrate, potassium nitrate... In the form of crystals, the substance has no color or aromatic qualities. Among the properties of potassium nitrate can be noted hygroscopicity to a small extent, non-volatility. The compound is not toxic to living organisms. Another property is its good degree of solubility in water, tendency to caking over time.

In nature, the compound occurs as a mineral nitrokalite. One of the most large deposits is located in the East Indies, in connection with which such a name as Indian saltpeter appeared. In small doses, it can be found in animals and plants.

In ancient times, nitrate was obtained from a mixture of limestone and manure, wood ash. Now the substance is extracted through the extraction of potash.

Applications

The compound is used in the food industry as an additive under the number E252. The additive has found its application in the production of cheeses. different kind in order to slow down the swelling process. In the case of high concentrations of the compound, a change in the color of the product is observed. In addition, the food additive is used in fish and meat products. Nitrate is also found in anchovies due to its coloring property.

In meat products, the compound undergoes transformation into nitrite, as a result, a specific color and smell of the product appears, and microbial activity decreases. Potassium nitrate has an antimicrobial effect, as a result of which it is often used only for its subsequent transformation into nitrites.

The substance found its application in agriculture as a double complex fertilizer for those plants that have a bad reaction to chlorine: citrus fruits, berry crops, tobacco, beets, grapes. In addition, nitrate is used as a microfertilizer for indoor plants, as well as in the greenhouse production of vegetables.

Potassium nitrate is used in electrovacuum production, optical glassmaking for the purpose of lightening and discoloration of technical crystal glasses, giving strength characteristics glass products.

Other areas of application:

production of enamels, matches, heat carriers;
metallurgical industry for hardening metals;
in the production of black powder, special pyrotechnic mixtures;
as a component of propellant;
in the production of toothpastes for sensitive teeth.

The effect of potassium nitrate on the human body

Potassium nitrate is characterized by a carcinogenic effect, that is, it provokes the development of malignant tumors under the condition of exposure external factors... But in doses that do not exceed the recommended ones, the additive does not have adverse effects on the human body.

The negative effect is explained by the transformation of the compound in the human body into nitrites and carcinogenic nitrosamines. The amount of nitrates that enter the body due to food additives is small compared to the content of substances of this group in vegetables and drinking water.

Long-term exposure to potassium nitrate on the body in small doses can provoke the following diseases and symptoms:

weakness;
dizziness;
headache;
mental disorders;
arrhythmia;
violation of spatial orientation;
kidney inflammation;
arrhythmia;
anemia.

As a food additive, nitrate is approved for use in the food industry on the territory of Ukraine, Russia, and the countries of the European Union. However, remember that foods containing potassium nitrate are not recommended for daily consumption.

Potassium nitrate properties

Outwardly, it is a crystalline powder that is odorless or colorless. It decomposes only at high temperatures (over 400 degrees), with the release of oxygen. May react with combustible materials.

One of the properties of potassium nitrate is good water solubility in addition, the substance has some hygroscopicity, but is odorless and not volatile. It also dissolves in glycerin, liquid ammonia, hydrazine, but does not dissolve in pure ethanol and ether. Can be cleaned by recrystallization.

Potassium nitrate use

The main application today is the use of potassium nitrate as a fertilizer in agriculture. This fertilizer combines two elements that block the assimilation of one another by plants.

In addition, an irreplaceable substance in pyrotechnics, the manufacture of black powder, caramel rocket fuel. It is used in such areas as the electric vacuum industry, optical glassmaking (with its help, technical crystal glasses are discolored and clarified, and glass products are given strength).

Potassium nitrate is also used in metallurgy as an oxidizing agent, for example, in the processing of nickel ores.

In the food industry, the preservative E252 is used in the manufacture of meat products such as sausages, sausages and canned meat, as well as for the production of cheeses. Due to the high content of potassium nitrate, the product can change color, which is why it is used in the processing of anchovies. It should be noted that the preservative has some antimicrobial effect.

In addition, this food preservative is found in prophylactic toothpastes.

The harm of potassium nitrate

E252 preservative can be harmful to human health. This is due to the fact that when consumed for cooking food, a fairly large part of it enters the body. There, it can be transformed into nitrites, which have negative effects on internal systems the human body.

If potassium nitrate is ingested for a long time and in large doses, it can affect the kidneys., cause anemia, impaired pulse. The main symptom of its excess in the body is abdominal pain, in addition, vomiting, weakness, and impaired coordination may occur. In asthma sufferers, it can cause choking due to its ability to interfere with the oxygen balance in the blood. Exacerbates some diseases, is considered a provocateur of the development of tumors. For children, the use of food products in which this food additive is present is categorically contraindicated.

The composition and properties of potassium nitrate

The basis of the substance is nitric acid and sodium. The salt obtained as a result of the combination of these elements is a white or yellowish powder, endowed with neither smell nor taste. In its natural form, the substance consists of colorless, elongated, needle-shaped crystals.

Potassium nitrate owes its particular popularity and wide range of applications to its properties:

does not have volatility;
has a weakly pronounced hygroscopicity;
non-toxic;
absolutely harmless to humans;
perfectly soluble in water, liquid ammonia, glycerin and hydrazine.

In addition, potassium nitrate is one of the strongest oxidizing agents, and becomes explosive when exposed to high temperatures. It is capable of explosive contact with flammable materials. This property of the substance allows it to be successfully used in the production of fireworks.

If the reaction involves organic matter- saltpeter can easily ignite them, therefore the use of potassium nitrate requires caution and special safety measures.

Who needs potassium nitrate

Potassium nitrate surrounds a person from all sides. This substance is actively used in many economic areas. Modern man daily uses items made with potassium nitrate. He even eats it along with food.

Agriculture. It is used as a universal fertilizer capable of increasing the yield of vegetables and fruits many times over.
Food industry. It is included in the composition of products in the form of E252 preservative. Responsible for their protection from the development of putrefactive bacteria, retains color and attractive appearance. In addition, potassium nitrate is used in the manufacture of certain types of cheeses, sausages, and canned fish.
Glass production. Used to brighten crystal.
Space industry. Potash nitrate is the basis for the manufacture of solid propellants for rockets. Its mass in this product reaches 65%.
Metallurgy. Due to its pronounced oxidizing properties, it is used in the process of nickel-containing ores.
Pyrotechnic items. It is the basis for obtaining gunpowder, which is used in the military industry, and is also used for the manufacture of fireworks.
Pharmacology. When added to toothpaste is able to significantly reduce the sensitivity of tooth enamel. It is part of some types of eye drops.

Rules for the use of potassium nitrate

Regardless of in which of the branches of the national economy potash nitrate is used, its properties force users to strictly follow the rules of application.

Given the ability of saltpeter to ignite spontaneously, as well as to enter it into chemical reactions, the substance was assigned a hazard class 3, which must necessarily be reflected in the conditions of its transportation and storage:

Transportation. Potassium nitrate is transported only in specially designed wagons or other specialized modes of transport closed type.
Storage. To prevent the powder from compressed over time, saltpeter should only be stored in a sealed package. Place it away from flammable substances and hot objects. The warehouse should be a closed room equipped with a fire alarm system.

Safety rules for use as fertilizer

Potassium nitrate is very actively used in agricultural production as a fertilizer. It contains in its composition the elements necessary for the growth and enhancement of the vegetative functions of plants, but in this area of application, safety rules should be adhered to.

It is possible to feed plants only with a substance in dry form or with a solution of saltpeter with water. Under no circumstances should it be mixed with organic fertilizers such as peat, straw, sawdust or manure.
When using fertilizer, you must strictly observe the measure. Over the summer, experts recommend no more than 3-4 dressings. In case of excessive use of nitrate, plants can accumulate a large number of nitrates, which can have a harmful effect on the human body.
Workers in direct contact with fertilizer should follow personal safety precautions using respirators to protect respiratory tract, rubber gloves and utensils not intended for eating.

Potassium nitrate belongs to the category of "useful" chemistry, which can greatly facilitate and even beautify a person's life. Do not be alarmed when you see the designation E252 on the label of your favorite sausage. It has been proven that potassium nitrate is not harmful to humans.

However, it should be remembered that excessive consumption of it with foods containing high level nitrates can have Negative influence on health, therefore it is so important to observe safety measures when using this substance in the field of agriculture.

Potassium nitrate is known under several names: potassium nitrate or technical potassium nitrate. The chemical formula is: KNO3. This substance has become widespread in different areas industry, while chemical production it is given Special attention.

By appearance potassium nitrate is a white crystalline powder, sometimes with a yellowish-white tint. Odorless. Potassium nitrate dissolves well in water.

Chemical properties, first of all, are expressed by the fact that potassium nitrate is a rather strong oxidizing agent; it reacts with other substances, primarily reducing agents and combustible materials.

Areas of use

Potassium nitrate is mainly used in the chemical, electrical, radio and engineering industries, glass and some other areas. Widely used in national economy, this applies to the agricultural industry. This substance can be found in both wholesale and retail.

Since the areas of application are quite diverse, potassium nitrate is of several varieties. Manufacturers produce four main brands. The first A is intended for the electrovacuum industry. A1 - optical glassmaking. Grade B denotes potassium nitrate for the production of black powder, special mixtures, as well as for use in decolorizing glass and brightening crystal, thanks to which glass products also become stronger.

Regardless of the industry in which potassium nitrate is used, the application should take into account all basic properties of this substance, and it is also necessary to observe certain rules safety precautions. Potassium nitrate is a strong oxidizing agent, therefore it can lead to spontaneous combustion of combustible substances. According to the effect on the body, saltpeter is assigned the third hazard class.

Similar safety precautions must be followed during transportation. Potassium nitrate is transported only in specialized wagons, or by any other closed transport.

Potassium nitrate can only be stored in a packed form in closed, safe rooms, separate from other hot or flammable substances. Failure to comply with these rules increases the risk of explosion or fire.

Despite the fact that this compound occurs in nature, chemical reactions are the main way of its appearance. In the process of using saltpeter, it can also enter into various reactions itself. Considering potassium nitrate can be studied based on the received data.

The use of potassium nitrate

Despite its widespread use in various industries, potassium nitrate is most often used in agriculture. It is a first-class plant fertilizer. Saltpeter targets some varieties that do not react well with other types of fertilizers. This includes many berry and citrus crops, grapes, tobacco, beets. At greenhouse cultivation vegetables and indoor plants, saltpeter is used to strengthen plants.

Saltpeter is able to significantly strengthen root system plants, it also normalizes and improves the structure. Thanks to this, plants become more resistant to external environmental influences.

Potassium nitrate is used in the food industry as the main products where this preservative is used are sausages, ham, sausages and canned meat.

Due to the wide demand, there is a constant need for the production of potassium nitrate of all four brands, only its quality must meet state standards.