The foundations for the division of salts into separate groups were laid down in the works of the French chemist and pharmacist G. Ruel(\(1703\)–\(1770\)) . It was he who, in \(1754\), proposed to divide the salts known by that time into acidic, basic and medium (neutral). Currently, other groups of this extremely important class of compounds are also distinguished.

Medium salts

Medium salts are called salts, which include a metallic chemical element and an acid residue.

The composition of ammonium salts instead of a metallic chemical element includes a monovalent ammonium group NH 4 I.

Examples of medium salts:

Na I Cl I - sodium chloride;
Al 2 III SO 4 II 3 - aluminum sulfate;
NH I 4 NO 3 I - ammonium nitrate.

Acid salts

Salts are called acid salts, which, in addition to the metallic chemical element and the acid residue, include hydrogen atoms.

Pay attention!

When compiling the formulas of acid salts, it should be borne in mind that the valency of the residue from the acid is numerically equal to the number of hydrogen atoms that were part of the acid molecule and replaced by the metal.

When composing the name of such a compound, the prefix " hydro", if there is one hydrogen atom in the remainder of the acid, and " dihydro", if the remainder of the acid contains two hydrogen atoms.

Examples of acid salts:

Ca II HCO 3 I 2 - calcium bicarbonate;
Na 2 I HPO 4 II - sodium hydrogen phosphate;
Na I H 2 PO 4 I - sodium dihydrogen phosphate.

The simplest example of acidic salts is baking soda, i.e. sodium bicarbonate\(NaHCO_3\).

Basic salts

Salts are called basic salts, which, in addition to the metallic chemical element and the acid residue, include hydroxo groups.

Basic salts can be considered as the product of incomplete neutralization of a polyacid base.

Pay attention!

When compiling the formulas of such substances, it should be borne in mind that the valence of the residue from the base is numerically equal to the number of hydroxo groups that have “left” the composition of the base.

When composing the name of the main salt, the prefix " hydroxo", if there is one hydroxo group in the remainder of the base, and " dihydroxo", if the remainder of the base contains two hydroxo groups.

Examples of basic salts:

MgOH I Cl I - magnesium hydroxochloride;
Fe OH II NO 3 2 I - iron hydroxonitrate (\ (III \));
Fe OH 2 I NO 3 I - iron dihydroxonitrate (\ (III \)).

A well-known example of basic salts is the green coating of copper hydroxocarbonate (\(II\)) \((CuOH)_2CO_3\), which forms over time on copper objects and objects made of copper alloys if they come into contact with humid air. The mineral malachite has the same composition.

Complex salts

Complex compounds are a diverse class of substances. The credit for creating a theory explaining their composition and structure belongs to the Nobel Prize in Chemistry \ (1913 \) Swiss scientist A. Werner (\(1866\)–\(1919\)). True, the term "complex compounds" in \ (1889 \) was introduced by another outstanding chemist, Nobel Prize winner \ (1909 \) W. Ostwald (\(1853\)–\(1932\)).

The composition of the cation or anion of complex salts contains complexing element associated with so-called ligands. The number of ligands that a complexing agent attaches is called coordination number. For example, the coordination number of divalent copper, as well as beryllium, zinc, is \(4\). The coordination number of aluminum, iron, trivalent chromium is \(6\).

In the name of the complex compound, the number of ligands connected to the complexing agent is displayed in Greek numerals: \ (2 \) - " di",\(3\)-" three", \(4\) - " tetra", \(5\) - " penta",\(6\)-" hexa". Both electrically neutral molecules and ions can act as ligands.

The name of a complex anion begins with an indication of the composition of the inner sphere.

If anions act as ligands, the ending “ -about»:

\(–Cl\) - chloro-, \(–OH\) - hydroxo-, \(–CN\) - cyano-.

If the ligands are electrically neutral water molecules, the name " aqua", and if ammonia - the name" ammine».

Then the complexing agent is called, using its Latin name and the ending "- at”, after which, without a space, Roman numerals in brackets indicate the degree of oxidation (if the complexing agent can have several degrees of oxidation).

After designating the composition of the inner sphere, the name of the cation of the outer sphere is indicated - the one that is outside the square brackets in the chemical formula of the substance.

Example:

K 2 Zn OH 4 - potassium tetrahydroxozincate,
K 3 Al OH 6 - potassium hexahydroxoaluminate,
K 4 Fe CN 6 - potassium hexacyanoferrate (\ (II \)) potassium.

In school textbooks, the formulas for complex salts of a more complex composition, as a rule, are simplified. For example, the formula of potassium tetrahydroxodiquaaluminate K Al H 2 O 2 OH 4 is usually written as the formula of tetrahydroxoaluminate.

If the complexing agent is part of the cation, then the name of the inner sphere is made in the same way as in the case of a complex anion, but the Russian name of the complexing agent is used and the degree of its oxidation is indicated in brackets.

Example:

Ag NH 3 2 Cl - diammine silver chloride,
Cu H 2 O 4 SO 4 - tetraaquacopper sulfate (\ (II \)).

Crystal hydrates of salts

Hydrates are the products of the addition of water to particles of a substance (the term is derived from the Greek hydro- "water").

Many salts precipitate out of solution as crystalline hydrates- crystals containing water molecules. In crystalline hydrates, water molecules are strongly associated with cations or anions that form a crystal lattice. Many salts of this type are essentially complex compounds. Although many of the crystalline hydrates have been known since time immemorial, the systematic study of their composition was initiated by the Dutch chemist B. Roseb (\(1857\)–\(1907\)).

In the chemical formulas of crystalline hydrates, it is customary to indicate the ratio of the amount of salt substance and the amount of water substance.

Pay attention!

The dot that divides the chemical formula of the crystalline hydrate into two parts, unlike mathematical expressions, does not indicate the action of multiplication and is read as a preposition "with".

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Food salt is essentially a universal product, a mineral that has been accompanying a person since ancient times. A long time ago, people realized the importance of this seasoning in their lives, which is why there are a number of proverbs and sayings, for example, “Eat a pound of salt with someone” or “Leave without salty bread” and of course many others, reflecting the great respect of the people for this product . And edible salt very often in many civilizations was used as a bargaining chip, for a certain small amount of which you could even buy yourself a slave.

The process of extracting table salt is not much different in our time from the ancient methods. Moreover, the extraction of certain species is carried out in almost every country. The production of edible salt is different, most often carried out in the following three ways:

• Salt is self-planting, which is formed by the natural evaporation of sea water.
• Self-planting salt obtained from the bottom of salt lakes, or in salt cave reservoirs.
• Rock edible salt, obtained through the development of mines. Such salt is not subjected to any heat treatment during extraction.

The chemical composition of edible salt

The chemical composition of edible salt according to GOST is actually very simple. This is a compound formed by the interaction of alkali and acid, two chemical elements - sodium and chlorine. Therefore, the formula of edible salt is NaCl. This compound is obtained in the form of white crystals (see photo), which we are used to seeing in our salt shakers.

Benefits of edible salt

The benefits of this product are very unlikely to be underestimated in a person's life. Nowadays, the variety of different types of salt on the shelves of shops and supermarkets is incredibly wide. You can see sea, and iodized, and Himalayan, and pink with black, and many other species. All of them differ in the place of extraction, cleaning methods and many other factors that affect the presence of additional useful ingredients in the composition of the salt.

Thanks to all this, this product has a huge number of useful properties. Every day, about five grams of this mineral must enter our body to maintain water balance. It also serves as the basis for the formation of hydrochloric acid in the stomach, which perform the lion's share of the digestive process. This mineral must be present in the blood and liver of a person, and even at the cellular level. Due to its unique composition, it helps to maintain the necessary level of electrolytes.

Application in cooking

The use of edible salt as an additive in cooking is used all over the world. There is not a single cuisine in the world where this seasoning would not be used. In addition to adding flavor, it is also used as a preservative for the long-term preservation of vegetables, meat, and fish. It is important to remember that it should be used in moderation.

Useful properties and use in treatment

The beneficial properties of edible salt and the use of this composition in the treatment have been known since ancient times and are confirmed by modern research. Sodium chloride, this is the name of the compound, due to its indispensability in biological processes, both in humans and the rest of the plant and animal world, plays an important role in the life of every organism.

Sodium is, in fact, the main cation involved in maintaining the required level of acid-base balance, moreover, it is he who is responsible for the constancy of osmotic pressure.

The sodium-potassium compound ensures the penetration of glucose and amino acids through the cell membrane. With the insufficiency of this component in the human body, the transmission of nerve impulses and the activity of various muscles, including the heart, will not be able to function properly.

Without sodium, it will be quite difficult for the colon to absorb certain nutrients.

Chlorine is responsible for the formation of hydrochloric acid and some other substances in the body responsible for the breakdown of fats. It is the main stimulant of the reproductive and nervous systems, and with its insufficient presence in the body, the full formation of bone and muscle tissues is impossible.

The use of salt to benefit the body is possible not only with the help of its ingestion. We can greatly improve our health by applying some topical sodium chloride recipes.

For example, salt baths are very popular to strengthen the nail plate. To get it, dissolve a few tablespoons in a cup of water and dip your fingertips in it for a few minutes.

Also, with a runny nose, it is advised to do such a warm-up: heat a glass of salt in a frying pan, pour it into a bag of gauze or canvas, and warm the bridge of the nose.

Even in the fight against excess weight, extra food salt will become a faithful assistant. Dissolve two kilograms of salt in a bath of hot water and plunge into the resulting solution for fifteen minutes.

In addition to these, there are many other ways to use this product for the benefit of your own body.

Harm of salt and contraindications

There are many theories about the harm of this product. The most important thing that all researchers note is not to overdo it in use. Fifteen grams of sodium chloride per day is considered the optimal norm for a healthy adult. And it should be counted as such. Ten grams enters the body already in the composition of consumed products. And only five grams can be consumed additionally when preparing various dishes.

Extra food salt can in large quantities lead to clogging of the cells of our body with various harmful substances, can cause tissue edema and additional stress on arterial vessels and the heart. It should be borne in mind that excessive consumption of this product can lead to complications in the work of the whole organism. In addition, the nutritional value of edible salt is also quite high, and an excessive amount of salt in the body leads to additional stagnation of water in the body.

Therefore, it is worth being moderate in salting dishes, and, if possible, avoid additional intakes of this mineral, because the benefits and harms of edible salt will always depend only on your prudence. And then this ancient flavoring product will serve only for the benefit of your health.

Bases can interact:

• with non-metals

  6KOH + 3S → K2SO 3 + 2K 2 S + 3H 2 O;

• with acidic oxides -

  2NaOH + CO 2 → Na 2 CO 3 + H 2 O;

• with salts (precipitation, gas release) -

  2KOH + FeCl 2 → Fe(OH) 2 + 2KCl.

There are also other ways to get:

• the interaction of two salts -

  CuCl 2 + Na 2 S → 2NaCl + CuS↓;

• reaction of metals and non-metals -
• combination of acidic and basic oxides -

  SO 3 + Na 2 O → Na 2 SO 4;

• interaction of salts with metals -

  Fe + CuSO 4 → FeSO 4 + Cu.

Chemical properties

Soluble salts are electrolytes and are subject to dissociation reactions. When interacting with water, they disintegrate, i.e. dissociate into positively and negatively charged ions - cations and anions, respectively. Metal ions are cations, acid residues are anions. Examples of ionic equations:

• NaCl → Na + + Cl - ;
• Al 2 (SO 4) 3 → 2Al 3 + + 3SO 4 2− ;
• CaClBr → Ca2 + + Cl - + Br - .

In addition to metal cations, ammonium (NH4 +) and phosphonium (PH4 +) cations may be present in salts.

Other reactions are described in the table of chemical properties of salts.

Rice. 3. Isolation of sediment upon interaction with bases.

Some salts, depending on the type, decompose when heated into a metal oxide and an acid residue or into simple substances. For example, CaCO 3 → CaO + CO 2, 2AgCl → Ag + Cl 2.

What have we learned?

From the 8th grade chemistry lesson, we learned about the features and types of salts. Complex inorganic compounds consist of metals and acid residues. May include hydrogen (acid salts), two metals, or two acid residues. These are solid crystalline substances that are formed as a result of the reactions of acids or alkalis with metals. React with bases, acids, metals, other salts.

When you hear the word "salt", the first association is, of course, cooking, without which any dish will seem tasteless. But this is not the only substance that belongs to the class of salt chemicals. You can find examples, composition and chemical properties of salts in this article, as well as learn how to correctly compose the name of any of them. Before continuing, let's agree that in this article we will consider only inorganic medium salts (obtained by the reaction of inorganic acids with complete replacement of hydrogen).

Definition and chemical composition

One of the definitions of salt is:

• (i.e., consisting of two parts), which includes metal ions and an acid residue. That is, it is a substance resulting from the reaction of an acid and a hydroxide (oxide) of any metal.

There is another definition:

• This compound is a product of complete or partial replacement of hydrogen ions of an acid with metal ions (suitable for medium, basic and acidic).

Both definitions are correct, but do not reflect the whole essence of the salt production process.

Salt classification

Considering various representatives of the class of salts, you can see that they are:

• Oxygen-containing (salts of sulfuric, nitric, silicic and other acids, the acid residue of which includes oxygen and another non-metal).
• Anoxic, i.e., salts formed during the reaction, the residue of which does not contain oxygen - hydrochloric, hydrobromic, hydrogen sulfide and others.

By the number of substituted hydrogens:

• Monobasic: hydrochloric, nitric, hydroiodic and others. An acid contains one hydrogen ion.
• Dibasic: Two hydrogen ions are replaced by metal ions in the formation of a salt. Examples: sulfuric, sulfurous, hydrogen sulfide and others.
• Tribasic: in the composition of the acid, three hydrogen ions are replaced by metal ions: phosphoric.

There are other types of classifications by composition and properties, but we will not analyze them, since the purpose of the article is slightly different.

Learning to name correctly

Any substance has a name that is understandable only to residents of a certain region, it is also called trivial. Table salt is an example of a colloquial name; according to international nomenclature, it will be called differently. But in a conversation, absolutely any person familiar with the nomenclature of names will understand without any problems that we are talking about a substance with the chemical formula NaCl. This salt is a derivative of hydrochloric acid, and its salts are called chlorides, that is, it is called sodium chloride. You just need to learn the names of the salts given in the table below, and then add the name of the metal that formed the salt.

But the name is so simply compiled if the metal has a constant valence. And now let's look at the name), in which the metal with variable valency is FeCl 3. The substance is called ferric chloride. That is the correct name!

Acid Formula	Name of the acid	Acid residue (formula)	Nomenclatural name	Example and trivial name
HCl	hydrochloric	Cl-	chloride	NaCl (table salt, rock salt)
HI	hydroiodic	I-	iodide	NaI
HF	hydrofluoric	F-	fluoride	NaF
HBr	hydrobromic	br-	bromide	NaBr
H2SO3	sulphurous	SO 3 2-	sulfite	Na2SO3
H2SO4	sulfuric	SO 4 2-	sulfate	CaSO 4 (anhydrite)
HClO	hypochlorous	ClO-	hypochlorite	NaClO
HClO 2	chloride	ClO 2 -	chlorite	NaClO 2
HClO 3	chlorine	ClO 3 -	chlorate	NaClO 3
HClO 4	chloride	ClO 4 -	perchlorate	NaClO 4
H2CO3	coal	CO 3 2-	carbonate	CaCO 3 (limestone, chalk, marble)
HNO3	nitric	NO 3 -	nitrate	AgNO 3 (lapis)
HNO 2	nitrogenous	NO 2 -	nitrite	KNO 2
H3PO4	phosphoric	PO 4 3-	phosphate	AlPO 4
H2SiO3	silicon	SiO 3 2-	silicate	Na 2 SiO 3 (liquid glass)
HMnO 4	manganese	MnO4-	permanganate	KMnO 4 (potassium permanganate)
H2CrO4	chrome	CrO 4 2-	chromate	CaCrO 4
H 2 S	hydrogen sulfide	S-	sulfide	HgS (cinnabar)

Chemical properties

As a class, salts are characterized by their chemical properties in that they can interact with alkalis, acids, salts and more active metals:

1. When interacting with alkalis in solution, a prerequisite for the reaction is the precipitation of one of the resulting substances.

2. When interacting with acids, the reaction proceeds if a volatile acid, an insoluble acid, or an insoluble salt is formed. Examples:

• Volatile acids include carbonic, since it easily decomposes into water and carbon dioxide: MgCO 3 + 2HCl \u003d MgCl 2 + H 2 O + CO 2.
• The insoluble acid, silicic, is formed by the reaction of a silicate with another acid.
• One of the signs of a chemical reaction is the formation of a precipitate. What salts can be seen in the solubility table.

3. The interaction of salts with each other occurs only in the case of binding of ions, i.e. one of the formed salts precipitates.

4. To determine whether the reaction between the metal and the salt will go, you need to refer to the metal stress table (sometimes also called the activity series).

Only more active metals (located to the left) can displace the metal from the salt. An example is the reaction of an iron nail with blue vitriol:

CuSO 4 + Fe \u003d Cu + FeSO 4

Such reactions are characteristic of most representatives of the class of salts. But there are also more specific reactions in chemistry, the individual reflecting properties of salt, for example, decomposition upon incandescence or the formation of crystalline hydrates. Each salt is individual and unusual in its own way.

Salts are chemical compounds in which a metal atom is bonded to an acidic residue. The difference between salts and other compounds is that they have a pronounced ionic nature of the bond. That is why the bond is called ionic. The ionic bond is characterized by unsaturation and non-directionality. Examples of salts: sodium chloride or kitchen salt - NaCl, calcium sulfate or gypsum - CaSO4. Depending on how completely the hydrogen atoms in the acid or the hydroxo groups in the hydroxide are replaced, medium, acidic and basic salts are distinguished. The composition of the salt may include several metal cations - these are double salts.

Medium salts

Medium salts are salts in which hydrogen atoms are completely replaced by metal ions. Kitchen salt and gypsum are such salts. Medium salts cover a large number of compounds that are often found in nature, for example, blende - ZnS, pyrrite - FeS2, etc. This type of salt is the most common.

Medium salts are obtained by a neutralization reaction, when the base is taken in equimolar ratios, for example:
H2SO3 + 2 NaOH = Na2SO3 + 2 H2O
It turns out the average salt. If we take 1 mole of sodium hydroxide, then the reaction will go as follows:
H2SO3 + NaOH = NaHSO3 + H2O
It turns out the acid salt sodium hydrosulfite.

Acid salts

Acid salts are salts in which not all of the hydrogen atoms are replaced by a metal. Such salts are capable of forming only polybasic acids - sulfuric, phosphoric, sulfurous and others. Monobasic acids, such as hydrochloric, nitric and others, do not give.
Examples of salts: sodium bicarbonate or baking soda - NaHCO3, sodium dihydrogen phosphate - NaH2PO4.

Acid salts can also be obtained as medium salts with acid:
Na2SO3+ H2SO3 = 2NaHSO3

Basic salts

Basic salts are salts in which not all hydroxo groups are replaced by acidic residues. For example, - Al (OH) SO4, hydroxochloride - Zn (OH) Cl, copper dihydroxocarbonate or malachite - Cu2 (CO3) (OH) 2.

double salts

Double salts are salts in which two metals replace hydrogen atoms in the acid residue. Such salts are possible for polybasic acids. Examples of salts: potassium sodium carbonate - NaKCO3, potassium sulfate - KAl (SO4) 2 .. The most common double salts in everyday life are alum, for example, potassium alum - KAl (SO4) 2 12H2O. They are used to purify water, tan leather, and loosen dough.

mixed salts

Mixed salts are salts in which the metal atom is bonded to two different acidic residues, such as bleach - Ca(OCl)Cl.

The most valuable knowledge about substances, compounds, elements that surround a person and are part of his body, is the science of chemistry. It is chemistry that studies acids and salts, their resistance to media, formation, etc.

Acids and salts are complex substances of different origin.

salt

Salts - which are formed during the reaction of an acid with a base, during this process water is inevitably released.

Most of the known salts are formed by the interaction of substances with opposite properties. This reaction is:
- metal,
- metal,
- basic oxide and acid,
- base and acid
- other elements.

The reaction of a salt and an acid also produces a salt. There is another salt, which boils down to an indication of the complexity of the substance and its dissociation into cations and anions of acid residues.

Salts are divided into three main types: acidic, medium and basic. Acid salts arise with an excess of acid, they only slightly replace hydrogen cations in acids by. Basic salts are the product of partial substitution of a base for acidic residues. But medium salts replace all the positive charges of hydrogen in acidic molecules with charges, or, they say, metal cations.

Salts that have "hydro-" in their name are acidic, the numerical indicator reflects the number of hydrogen atoms. The name contains the prefix "hydroxo-". Some classes of salts have their own name, for example, these are alums.

acids

Acids are complex substances that consist of hydrogen atoms and an acid residue. All acids are electrolytes.

Acids are classified according to three main features: the presence of oxygen in the acid residue and the number of hydrogen atoms. Accordingly, according to the solubility of the acid, they are divided into soluble, insoluble and other reactions. The number of hydrogen atoms can vary, depending on which acids can be both monobasic and dibasic, and tribasic.

With the presence of oxygen, everything is simple: the acid residue is either oxygen or anoxic.

At their core, acids contain either one or more hydrogen atoms and an acidic residue. Due to the characteristic properties of acids, they have become widely used in industry and in everyday life. There are a great many varieties of acidic substances: citric, boric, lactic and salicylic are most of all used in everyday life.

For example, boric acid, which belongs to the class of weak acids, has a powder form with a crystalline structure. It dissolves best in hot water or special saline solutions. In the natural environment, boric acid can be found in mineral waters or hot springs.

Related videos

Sodium chloride, sodium chloride, sodium salt of hydrochloric acid are all different names for the same chemical substance - NaCl, which is the main component of table salt.

Instruction

Sodium chloride in its pure form is colorless crystals, but in the presence of impurities it can take on a yellow, pink, purple, blue or gray tint. In nature, NaCl occurs as the mineral halite, from which household salt is made. A huge amount of sodium chloride is also dissolved in sea water.