Chile saltpeter: a formula and properties. The chemical formula of ammonium nitrate

Modern researches of substances allow to open all their new possibilities. So, significantly expand the main areas of application. So, for example, in agriculture hundreds of various fertilizers are known, capable of helping crop plants grow, grow and grow. Just one of these is Chilean saltpeter, which was discovered in the 18th century.

Synonyms of names

It is interesting that for one substance there are sometimes characteristic whole series of different names. After all, some are given by people in everyday life, others come from the deposit, others are sources from the rational chemical nomenclature of compounds.

So it happened with the substance under consideration. Chilean nitrate has the following synonyms for the name:

• Sodium nitrate;
• Sodium nitrate;
• Sodium nitrate;
• Sodium nitrate;
• Nitrone.

Each of them reflects any information about this substance. For example, sodium nitrate indicates the composition of the compound, and therefore shows what the chemical formula of ammonium nitrate will be. This information is given to us by some other synonyms. The word "Chilean" uniquely characterizes the main sources of the mineral deposit.

The chemical formula of ammonium nitrate

The elemental composition of the substance is characterized by the following components: one sodium atom, one nitrogen atom and three oxygen atoms. Therefore, it can be concluded how from the chemical point of view will look Chilean nitrate. The formula will be recorded as NaNO ₃ . In a percentage ratio, the qualitative composition will be expressed as: 26/16/58%, respectively.

The crystal structure of the molecular lattice of sodium nitrate is a trigonal rhombohedron. In them, the oxygen atoms are closely grouped around the central nitrogen, being held near it by covalent polar interactions. Thus, a single NO ₃ ^- ion ^{is formed} , which is called the acid residue. At the same time, in the outer sphere there is a positively charged sodium cation Na ⁺ . Therefore, between the oppositely charged particles there is a strong electrostatic attraction. As a result, an ionic bond is formed.

The type of crystal is similar to that of feldspar (calcite). Therefore, this structure is not only Chilean saltpetre. The chemical formula reflects at once two types of chemical bonds in a molecule:

• Covalent polar;
• Ionic.

Also, the order of the combination of atoms in a molecule is clearly traced, and therefore it is easy to calculate the valencies and oxidation states of both atoms and ions by the formula.

Class of chemical compounds

Among the inorganic compounds there is a great variety. Therefore, all of them are divided into classes according to the manifested properties and the features of the composition and structure of the molecules.

Not an exception, and Chilean nitrate. The formula NaNO ₃ shows that this compound is a typical salt of nitric acid. Sodium, which consists of an alkali metal cation and the acid residue of one of the most powerful oxidants.

Thus, it is possible to unambiguously determine where the Chilean nitrate belongs - to the class of inorganic average salts.

Physical properties

According to these parameters, the substance in question can be characterized as follows.

1. Colorless, sometimes with a yellowish, reddish or gray hue of crystalline matter.
2. The crystals are long needle structures.
3. It has no smell.
4. The taste is an unpleasant, highly salty substance.
5. The melting point is 308 ° C.
6. If you heat above 380 ^o C, then, like all nitrates, Chilean nitrate decomposes to form metal and oxygen nitrite.
7. In water it dissolves quite well (at 100 ° C, 176 grams of salt, at ^about 0 ° C about 77 grams).
8. It also dissolves fairly well in ammonia and hydrazine, and solubility in organic solvents such as ethanol, methanol or pyridine decreases sharply.
9. When a certain treatment becomes an explosive, however, it is difficult to use nitrate because of too good hygroscopicity.

Given the last parameter, sodium nitrate is stored in tightly packed polyethylene bags that do not allow moisture to pass through. It is also possible to find saltpeter in dark glass jars with ground glass stoppers. The main condition is fencing out of excessive lighting, temperature and humidity of the environment. If all the conditions are met, then the substance remains friable and dry, the crystals will be shallow.

Chemical properties

As we have already explained, Chilean nitrate is a class of inorganic compounds called salts. Chemical properties will be determined precisely by this feature.

1. It shows oxidative ability when interacting with nonmetals (sulfur, carbon). Reactions pass by heating the mixture.
2. It decomposes at temperatures above 380 ° C.
3. It reacts in the manner of exchange with salts of other metals, if the reaction follows the rule of Berthollet (gas is released, precipitate precipitates or a poorly dissociated substance is formed).

It is the chemical properties that largely explain the application of sodium nitrate.

Obtaining in industry

There are several ways in which the formation of sodium nitrate is possible.

1. Direct interaction of an alkali metal of sodium with an oxidizing agent (nitric acid). As a result, a replacement reaction occurs, nitrate is formed, gaseous nitrogen, nitrogen oxides II and I, water are released.
2. The reaction between sodium oxide and nitric acid. It turns sodium nitrate and water.
3. The interaction of sodium hydroxide or sodium hydroxide with nitrogen oxides I and II (a mixture called nitrous gas).
4. Exchange interaction between calcium nitrate and sodium sulfate. As a result, a precipitate of sparingly soluble calcium sulfate and a solution of nitrate are formed.
5. Another laboratory method is the reaction between ammonium nitrate and baking soda or alkali.
6. Also, the method used in the laboratory is the interaction of an exchange mechanism between silver nitrate (in the common language of lapis) and ordinary rock salt, that is, sodium chloride.
7. The industrial method, or the method used in mining, is leaching and subsequent crystallization from the deposits, which is carried out in a countercurrent method.

To date - this is all the ways by which it is possible to obtain a sufficient amount of sodium nitrate.

Production and deposits

The main deposits of the substance under consideration are:

• Chile;
• South-west Africa;
• California.

The rest of the seats are not as rich for the content of the connection. The largest export supplies of raw materials were always dealt with by Chileans. This is also due to one of the names of sodium nitrate.

Chilean nitrate is a source of nitrogen for plants, since its main historically developed field of application is agriculture, where it acts as a fertilizer.

Areas of use

For the first time this miraculous means of soil fertilization became known in 1825. However, then saltpeter did not find its buyer and remained forgotten. Five years later, it was used for plant nutrition assistance for the first time and was amazed at the results. Ever since, the consumption of this fertilizer has become massive. By 1870, it reached 150 thousand tons a year!

Today, agriculture is not the only area in which Chilean saltpetre is needed. The application has significantly expanded its boundaries.

1. As a preservative of meat and sausage products in the food industry.
2. Raw materials for the production of smoky powder and other explosives.
3. Metalworking industry.
4. Manufacture of heat-accumulating compounds.
5. In the production of glass.
6. For the production of a salt mixture - a salt-like refrigerant.
7. In rocket fuel.
8. In pyrotechnic products.

Obviously, the areas of application of sodium nitrate are quite extensive. In addition, for a long time it remained practically the only source for the synthesis of nitric acid. Today, for this purpose, it is no longer used, because the acid is produced by alternative synthetic methods.