Sodium (Na) is the main regulator of water balance in the body. Sodium. properties of sodium. The use of sodium Why a simple substance formed by sodium is a metal

Lecture plan:

1. Distribution of sodium in nature.

2. Historical reference.

3. Physical properties of sodium

4. 4. Chemical properties of sodium

5. Obtaining sodium.

6. 6. Obtaining sodium.

Sodium(Natrium), Na, a chemical element of group I of the periodic system of Mendeleev: atomic number 11, atomic mass 22.9898; a silvery-white soft metal that rapidly oxidizes from the surface in air. The natural element consists of one stable isotope 23 Na.

Historical reference. Natural sodium compounds - common salt NaCl, soda Na 2 CO 3 - have been known since ancient times. The name "Sodium", derived from the Arabic natrun, Greek. nitron, originally referred to natural soda. Already in the 18th century, chemists knew many other sodium compounds. However, the metal itself was obtained only in 1807 by G. Davy by electrolysis of caustic soda NaOH. In the UK, USA, France, the element is called Sodium (from the Spanish word soda - soda), in Italy - sodio.

Spreadingnatria in nature.

Sodium is a typical element in the upper part of the earth's crust. Its average content in the lithosphere is 2.5% by weight, in acidic igneous rocks (granites and others) 2.77, in basic (basalts and others) 1.94, in ultrabasic (mantle rocks) 0.57. Due to the isomorphism of Na + and Ca 2+ , due to the proximity of their ionic radii, sodium-calcium feldspars (plagioclases) are formed in igneous rocks. In the biosphere, there is a sharp differentiation of sodium: sedimentary rocks are on average depleted in sodium (in clays and shales 0.66%), there is little of it in most soils (average 0.63%). The total number of sodium minerals is 222. Na is slightly retained on the continents and is brought by rivers to the seas and oceans, where its average content is 1.035% (Na is the main metallic element of sea water). Evaporation in coastal-marine lagoons, as well as in continental lakes of steppes and deserts, precipitates sodium salts, which form strata of salt-bearing rocks. The main minerals that are the source of Sodium and its compounds are halite (rock salt) NaCl, Chilean saltpeter NaNO 3, thenardite Na 2 SO 4, mirabilite Na 2 SO 4 10H 2 O, trona NaH (CO 3) 2 2H 2 O Na is an important bioelement, living matter contains on average 0.02% Na; there is more of it in animals than in plants.

Physical propertiesnatria

At ordinary temperature, sodium crystallizes in a cubic lattice, a = 4.28 Å. Atomic radius 1.86Å, ionic radius Na + 0.92Å. Density 0.968 g / cm 3 (19.7 ° C), t pl 97.83 ° C, t bp 882.9 ° C; specific heat capacity (20 °C) 1.23 10 3 j/(kg K) or 0.295 cal/(g deg); thermal conductivity coefficient 1.32 10 2 W/(m K) or 0.317 cal/(cm sec deg); temperature coefficient of linear expansion (20 °C) 7.1 10 -5 ; electrical resistivity (0 °C) 4.3 10 -8 ohm m (4.3 10 -6 ohm cm). Sodium is paramagnetic, specific magnetic susceptibility +9.2·10 -6 ; very plastic and soft (easily cut with a knife).

Chemical propertiesnatria

The normal electrode potential of Sodium is -2.74 V; electrode potential in the melt -2.4 V. Sodium vapor gives the flame a characteristic bright yellow color. The configuration of the outer electrons of the atom is 3s 1 ; in all known compounds, sodium is monovalent. Its chemical activity is very high. Upon direct interaction with oxygen, depending on the conditions, Na 2 O oxide or Na 2 O 2 peroxide is formed - colorless crystalline substances. With water, sodium forms hydroxide NaOH and H 2 ; the reaction may be accompanied by an explosion. Mineral acids form the corresponding water-soluble salts with sodium, but with respect to 98-100% sulfuric acid, sodium is relatively inert.

The reaction of Sodium with hydrogen begins at 200 °C and leads to the formation of NaH hydride, a colorless hygroscopic crystalline substance. Sodium interacts directly with fluorine and chlorine already at ordinary temperatures, with bromine - only when heated; there is no direct interaction with iodine. It reacts violently with sulfur, forming sodium sulfide, the interaction of sodium vapor with nitrogen in the field of a quiet electric discharge leads to the formation of Na 3 N nitride, and with carbon at 800-900 ° C, to the formation of Na 2 C 2 carbide.

Sodium dissolves in liquid ammonia (34.6 g per 100 g NH 3 at 0°C) to form ammonia complexes. When gaseous ammonia is passed through molten sodium at 300-350 °C, sodiumamine NaNH 2 is formed - a colorless crystalline substance that is easily decomposed by water. A large number of organosodium compounds are known, which are very similar in chemical properties to organolithium compounds, but surpass them in reactivity. Organosodium compounds are used in organic synthesis as alkylating agents.

Sodium is a constituent of many practically important alloys. Alloys of Na - K, containing 40-90% K (by mass) at a temperature of about 25 ° C, are silvery-white liquids, characterized by high chemical activity, flammable in air. The electrical and thermal conductivity of liquid Na-K alloys is lower than the corresponding values ​​for Na and K. Sodium amalgams are easily obtained by introducing metallic sodium into mercury; above 2.5% Na (by mass) at ordinary temperature are already solids.

Receiptnatria.

The main industrial method for obtaining sodium is the electrolysis of sodium chloride melt NaCl containing additives KCl, NaF, CaCl 2 and others, which reduce the melting point of the salt to 575-585 °C. The electrolysis of pure NaCl would lead to large losses of Sodium from evaporation, since the melting points of NaCl (801 °C) and the boiling points of Na (882.9 °C) are very close. Electrolysis is carried out in electrolyzers with a diaphragm, cathodes are made of iron or copper, anodes are made of graphite. Simultaneously with sodium, chlorine is obtained. The old method of obtaining Sodium is the electrolysis of molten sodium hydroxide NaOH, which is much more expensive than NaCl, but decomposes electrolytically at a lower temperature (320-330 °C).

Applicationnatria.

Sodium and its alloys are widely used as coolants for processes requiring uniform heating in the range of 450-650 °C - in aircraft engine valves and especially in nuclear power plants. In the latter case, Na-K alloys serve as liquid-metal coolants (both elements have low thermal neutron absorption cross sections, for Na 0.49 barn), these alloys are distinguished by high boiling points and heat transfer coefficients and do not interact with structural materials at high temperatures developed in power plants. nuclear reactors. The NaPb compound (10% Na by mass) is used in the production of tetraethyl lead, the most effective antiknock agent. In a lead-based alloy (0.73% Ca, 0.58% Na, and 0.04% Li) used to make railcar axle bearings, Sodium is a hardening additive. In metallurgy, sodium serves as an active reducing agent in the production of certain rare metals (Ti, Zr, Ta) by metallothermic methods; in organic synthesis - in the reactions of reduction, condensation, polymerization and others.

Due to the high chemical activity of sodium, its handling requires caution. Especially dangerous is contact with sodium water, which can lead to fire and explosion. Eyes must be protected by goggles, hands by thick rubber gloves; Contact of sodium with wet skin or clothing can cause severe burns.

-element the main subgroup of the first group, the third period of the periodic system of chemical elements of D. I. Mendeleev, with atomic number 11. It is denoted by the symbol Na (lat. Natrium). The simple substance sodium (CAS number: 7440-23-5) is a soft, silvery-white alkali metal.

History and origin of the name

Diagram of the sodium atom

Sodium (or rather, its compounds) has been used since ancient times. For example, soda (natron), found naturally in the waters of soda lakes in Egypt. The ancient Egyptians used natural soda for embalming, bleaching canvas, cooking food, making paints and glazes. Pliny the Elder writes that in the Nile Delta, soda (it contained a sufficient proportion of impurities) was isolated from river water. It went on sale in the form of large pieces, due to the admixture of coal, painted gray or even black.

Sodium was first obtained by the English chemist Humphry Davy in 1807 by electrolysis of solid NaOH.

The name "sodium" (natrium) comes from the Arabic natrun in Greek - nitron and originally it referred to natural soda. The element itself was formerly called Sodium.

Receipt

The first way to obtain sodium was the reduction reaction sodium carbonate coal when heating a close mixture of these substances in an iron container to 1000 ° C:

Na 2 CO 3 + 2C \u003d 2Na + 3CO

Then another method of obtaining sodium appeared - electrolysis of a melt of caustic soda or sodium chloride.

Physical properties

Qualitative determination of sodium using a flame - bright yellow color of the emission spectrum "D-lines of sodium", doublet 588.9950 and 589.5924 nm.

Sodium is a silvery-white metal, in thin layers with a violet tint, plastic, even soft (easily cut with a knife), a fresh cut of sodium glistens. The values ​​of electrical conductivity and thermal conductivity of sodium are quite high, the density is 0.96842 g / cm³ (at 19.7 ° C), the melting point is 97.86 ° C, the boiling point is 883.15 ° C.

Chemical properties

Alkali metal, easily oxidized in air. To protect against atmospheric oxygen, metallic sodium is stored under a layer of kerosene. Sodium is less active than lithium, so with nitrogen reacts only when heated:

2Na + 3N 2 = 2NaN 3

With a large excess of oxygen, sodium peroxide is formed

2Na + O 2 \u003d Na 2 O 2

Application

Metallic sodium is widely used in preparative chemistry and industry as a strong reducing agent, including metallurgy. Sodium is used in the production of highly energy-intensive sodium-sulfur batteries. It is also used in truck exhaust valves as a heat sink. Occasionally, metallic sodium is used as a material for electrical wires designed for very high currents.

In an alloy with potassium, as well as with rubidium and cesium used as a highly efficient heat transfer medium. In particular, an alloy of composition sodium 12%, potassium 47 %, cesium 41% has a record low melting point of −78 °C and has been proposed as a working fluid for ion rocket engines and as a coolant for nuclear power plants.

Sodium is also used in high-pressure and low-pressure discharge lamps (HLD and HLD). Lamps NLVD type DNaT (Arc Sodium Tubular) are very widely used in street lighting. They give off a bright yellow light. The service life of HPS lamps is 12-24 thousand hours. Therefore, gas-discharge lamps of the DNaT type are indispensable for urban, architectural and industrial lighting. There are also lamps DNaS, DNaMT (Arc Sodium Matte), DNaZ (Arc Sodium Mirror) and DNaTBR (Arc Sodium Tubular Without Mercury).

Sodium metal is used in the qualitative analysis of organic matter. An alloy of sodium and the test substance is neutralized ethanol, add a few milliliters of distilled water and divide into 3 parts, J. Lassen's test (1843), aimed at determining nitrogen, sulfur and halogens (Beilstein test)

Sodium chloride (common salt) is the oldest used flavoring and preservative.
- Sodium azide (Na 3 N) is used as a nitriding agent in metallurgy and in the production of lead azide.
- Sodium cyanide (NaCN) is used in the hydrometallurgical method of leaching gold from rocks, as well as in steel nitrocarburizing and in electroplating (silver, gilding).
- Sodium chlorate (NaClO 3) is used to destroy unwanted vegetation on the railway track.

Biological role

In the body, sodium is mostly outside the cells (about 15 times more than in the cytoplasm). This difference is maintained by the sodium-potassium pump, which pumps out the sodium that has entered the cell.

Together withpotassiumsodium performs the following functions:
Creation of conditions for the occurrence of membrane potential and muscle contractions.
Maintenance of osmotic concentration of blood.
Maintaining acid-base balance.
Normalization of water balance.
Ensuring membrane transport.
Activation of many enzymes.

Sodium is found in almost all foods, although the body gets most of it from table salt. Absorption mainly occurs in the stomach and small intestine. Vitamin D improves the absorption of sodium, however, excessively salty foods and foods rich in proteins interfere with normal absorption. The amount of sodium ingested with food indicates the amount of sodium in the urine. Sodium-rich foods are characterized by accelerated excretion.

Sodium deficiency in the diet balanced food does not occur in humans, however, some problems may arise with vegetarian diets. Temporary deficiency can be caused by diuretic use, diarrhea, profuse sweating, or excess water intake. Symptoms of sodium deficiency are weight loss, vomiting, gas in the gastrointestinal tract, and malabsorption. amino acids and monosaccharides. Prolonged deficiency causes muscle cramps and neuralgia.

An excess of sodium causes swelling of the legs and face, as well as an increased excretion of potassium in the urine. The maximum amount of salt that can be processed by the kidneys is approximately 20-30 grams, a larger amount is already life-threatening.

Sodium is one of the alkali metals. The table of chemical elements shows it as an atom belonging to the third period and to the first group.

Physical properties

In this section, the characteristic of sodium from the point of view of physics will be considered. To begin with, in its pure form it is a silvery solid with a metallic luster and low hardness. Sodium is so soft that it can be easily cut with a knife. The melting point of this substance is quite low and is seventy-nine degrees Celsius. The atomic mass of sodium is also small, we will talk about it later. The density of this metal is 0.97 g/cm 3 .

Chemical characterization of sodium

This element has a very high activity - it is able to quickly and violently react with many other substances. Also, the table of chemical elements allows you to determine such a value as the molar mass - for sodium it is twenty-three. One mole is such an amount of a substance that contains 6.02 x 10 to the 23rd degree of atoms (molecules, if the substance is complex). Knowing the molar mass of an element, you can determine how much a specific number of moles of a given substance will weigh. For example, two moles of sodium weigh forty-six grams. As mentioned above, this metal is one of the most reactive, it belongs to the alkali, respectively, its oxide can form an alkali (strong bases).

How oxides are formed

All substances of this group, including in the case of sodium, can be obtained by burning the original. Thus, the metal reacts with oxygen, which leads to the formation of an oxide. For example, if we burn four moles of sodium, we spend one mole of oxygen and get two moles of oxide of this metal. The formula of sodium oxide is Na 2 O. The reaction equation looks like this: 4Na + O 2 \u003d 2Na 2 O. If you add water to the resulting substance, an alkali is formed - NaOH.

Taking one mole of oxide and water, we get two moles of base. Here is the equation for this reaction: Na 2 O + H 2 O = 2NaOH. The resulting substance is also called sodium hydroxide. This is due to its pronounced alkaline properties and high chemical activity. Like strong acids, caustic sodium actively reacts with salts of low-active metals, organic compounds, etc. During the interaction with salts, an exchange reaction occurs - a new salt and a new base are formed. Caustic sodium solution can easily destroy fabric, paper, skin, nails, so it requires compliance with safety regulations while working with it. It is used in the chemical industry as a catalyst, as well as in everyday life as a means to eliminate the problem of clogged pipes.

Reactions with halogens

These are simple substances consisting of chemical elements that belong to the seventh group of the periodic system. Their list includes fluorine, iodine, chlorine, bromine. Sodium is able to react with all of them to form compounds such as sodium chloride/bromide/iodide/fluoride. To carry out the reaction, you need to take two moles of the metal in question, add one mole of fluorine to it. As a result, we obtain sodium fluoride in an amount of two moles. This process can be written as an equation: Na + F 2 = 2NaF. Sodium fluoride, which we received, is used in the production of toothpastes against caries, as well as detergents for various surfaces. Similarly, by adding chlorine, one can obtain (kitchen salt), sodium iodide, which is used in the manufacture of metal halide lamps, sodium bromide, used as a remedy for neuroses, insomnia, hysteria and other disorders of the nervous system.

With other simple substances

Reactions of sodium with phosphorus, sulfur (sulphur), carbon (carbon) are also possible. Such chemical interactions can be carried out only if special conditions are created in the form of high temperature. Thus, an addition reaction takes place. With its help, you can get substances such as sodium phosphide, sodium sulfide, sodium carbide.

An example is the addition of atoms of a given metal to phosphorus atoms. If we take three moles of the metal in question and one mole of the second component, then heat them, we get one mole of sodium phosphide. This reaction can be written as the following equation: 3Na + P = Na 3 P. In addition, sodium is able to react with nitrogen as well as hydrogen. In the first case, the nitride of the given metal is formed, in the second, the hydride. Examples include the following equations of chemical reactions: 6Na + N2 = 2Na 3 N; 2Na + H2 = 2NaH. The first interaction requires an electrical discharge, the second requires a high temperature.

Reactions with acids

The characterization of sodium does not end with simple ones. This metal also reacts with all acids. As a result of such chemical interactions, hydrogen is also formed. For example, when the metal in question reacts with hydrochloric acid, kitchen salt and hydrogen are formed, which evaporates. This reaction can be expressed using the reaction equation: Na + HCl \u003d NaCl + H 2. This kind of chemical interaction is called a substitution reaction. It can also be used to obtain salts such as phosphate, nitrate, nitrite, sulfate, sulfite, sodium carbonate.

Salt interaction

Sodium reacts with salts of all metals except potassium and calcium (they are more reactive than the element in question). In this case, as in the previous one, a substitution reaction occurs. The atoms of the metal under consideration take the place of the atoms of a chemically weaker metal. Thus, by mixing two moles of sodium and one mole of magnesium nitrate, we get two moles in an amount, as well as pure magnesium - one mole. The equation for this reaction can be written as follows: 2Na + Mg(NO 3) 2 = 2NaNO 3 + Mg. By the same principle, many other sodium salts can be obtained. Also, this method can be used to obtain metals from their salts.

What happens if you add water to sodium

This is perhaps one of the most common substances on the planet. And with it, the metal in question is also capable of entering into chemical interaction. In this case, caustic sodium, or sodium hydroxide, already discussed above, is formed.

To carry out such a reaction, you need to take two moles of sodium, add water to it, also in an amount of two moles, and as a result we get two moles of hydroxide and one mole of hydrogen, which will be released in the form of a gas with a pungent odor.

Sodium and its effects on organisms

Having considered this metal from a chemical point of view, let's move on to what is the biological characteristic of sodium. It is one of the important trace elements. First of all, it is one of the components of the animal cell. Here it performs important functions: together with potassium, it supports the formation and distribution of nerve impulses between cells, it is a necessary chemical element for osmotic processes (which is necessary, for example, for the functioning of kidney cells). In addition, sodium is responsible for the water-salt balance of the cell. Also, without this chemical element, it is impossible to transport glucose through the blood, which is so necessary for the functioning of the brain. This metal is also involved in the process of muscle contraction.

This trace element is needed not only by animals - sodium in the plant body also performs important functions: it participates in the process of photosynthesis, helping to transport carbohydrates, and is also necessary for the passage of organic and inorganic substances through membranes.

Too much and too little sodium

Excessive salt intake for a long time can lead to an increased content of this chemical element in the body. Symptoms of excess sodium can be an increase in body temperature, swelling, increased nervous excitability, impaired functioning of the kidneys. In the event of the appearance of such symptoms, it is necessary to remove kitchen salt and products in which there is a lot of this metal from the diet (the list will be given below), and then immediately consult a doctor. Reduced sodium content in the body also leads to unpleasant symptoms and organ dysfunction. This chemical element can be washed out with prolonged use of diuretic drugs or when drinking only purified (distilled) water, with increased sweating and dehydration of the body. Symptoms of sodium deficiency are thirst, dry skin and mucous membranes, vomiting and nausea, poor appetite, impaired consciousness and apathy, tachycardia, and cessation of the full functioning of the kidneys.

Foods high in sodium

In order to avoid too high or too low content in the body of the chemical element in question, it is necessary to know which food has the most of it. First of all, this is the kitchen salt already mentioned above. It is 40% sodium. It can also be sea salt. In addition, this metal is found in soy and soy sauce. A large amount of sodium is observed in seafood. These are seaweed, most types of fish, shrimp, octopus, crab meat, caviar, crayfish, etc. The sodium content in them is due to the fact that these organisms live in a salty environment with a high concentration of salts of various metals that are important for the normal functioning of the body.

The use of this metal and some of its compounds

The use of sodium in industry is very versatile. First of all, this substance is used in the chemical industry. Here it is necessary to obtain substances such as the hydroxide of the metal in question, its fluoride, sulfates and nitrates. In addition, it is used as a strong reducing agent - to isolate pure metals from their salts. There is a special technical sodium intended for use in such purposes. Its properties are fixed in GOST 3273-75. In connection with the strong reducing properties mentioned above, sodium is widely used in metallurgy.

Also, this chemical element finds its application in the pharmaceutical industry, where it is most often needed to obtain its bromide, which is one of the main components of many sedatives and antidepressants. In addition, sodium can be used in the manufacture of gas discharge lamps - these will be sources of bright yellow light. A chemical compound such as sodium chlorate (NaClO 3) destroys young plants, so it is used to remove those from railway tracks to prevent overgrowth of the latter. Sodium cyanide has been widely used in the gold mining industry. With its help, this metal is obtained from rocks.

How sodium is obtained

The most common method is the reaction of the carbonate of the metal in question with carbon. To do this, it is necessary to heat the two indicated substances to a temperature of about a thousand degrees Celsius. As a result of this, two chemical compounds such as sodium and fumes are formed. When one mole of sodium carbonate reacts with two moles of carbon, two moles of the desired metal and three moles of carbon monoxide are obtained. The equation of the above reaction can be written as follows: NaCO 3 + 2С = 2Na + 3СО. Similarly, this chemical element can be obtained from its other compounds.

Qualitative reactions

The presence of sodium +, like any other cations or anions, can be determined by special chemical manipulations. A qualitative reaction to the sodium ion is burning - if present, its flame will be colored yellow.

Where can the chemical element in question be found in nature

First, as already mentioned, it is one of the components of both animal and plant cells. Also, its high concentration is observed in sea water. In addition, sodium is part of some minerals. This, for example, is sylvinite, its formula is NaCl. KCl, as well as carnallite, the formula of which is KCl.MgCl 2 .6H 2 O. The first of them has a heterogeneous structure with alternating multi-colored parts, orange, pink, blue, red can be found in its color. This mineral is completely soluble in water. Carnallite, depending on the place of formation and impurities, can also have different colors. It can be red, yellow, white, light blue, and also transparent. It has a soft luster, the rays of light in it are strongly refracted. These two minerals serve as raw materials for the production of metals that are part of them: sodium, potassium, magnesium.

Scientists believe that the metal that we examined in this article is one of the most common in nature, since it is two and a half percent in the earth's crust.

Sodium and its compounds have been known to people since ancient times. Probably the most popular and well-known compound is sodium chloride, better known as table salt. Salt is an indispensable component of almost any dish. According to scientists, people began to eat table salt several thousand years ago.

Another popular compound is sodium carbonate. Sodium carbonate is a common soda that is sold in any store. The substance has also been used by humans since ancient times as a detergent. Thus, people have been dealing with sodium and its compounds every day for many tens and hundreds of years. Sodium easily reacts with both metallic and non-metallic elements, forming alloys and compounds widely used in industry. Let's take a closer look at the properties and characteristics of this metal.

Characterization of sodium

Physical properties

Sodium is a soft, ductile metal that can be cut very easily with a knife. It has a silvery-white color, as well as a characteristic metallic sheen. Metal is a good conductor of heat and electricity. Sodium atoms are connected by a metallic bond.

Chemical properties

Sodium atoms, when reacting with other chemical elements, easily donate valence electrons. In this case, sodium atoms are converted into ions with a positive charge.

• Sodium oxidizes very quickly in the open air. That is why the metal is usually stored in kerosene.
• When burned in oxygen, it forms the compound sodium peroxide (Na 2 O 2)
• When heated, sodium reacts with hydrogen to form a hydride (2NaH)
• Sodium easily reacts with non-metals such as sulfur, forfor and others.
• Also, sodium is able to react with metals. In this case, various alloys are formed, which are widely used in production and industry.
• Sodium reacts violently with water.

Finding sodium in nature

Sodium is in seventh place in the list of the most common elements on Earth. Sodium is also the fifth most common metal in the world. Among metals, only aluminum, iron, calcium and magnesium are more common than sodium.

Sodium does not occur in nature in its pure form. The reason for this is the high chemical activity of sodium. The element occurs naturally as chloride, carbonate, nitrate, sulfate, and other salts.

Where is sodium found in nature?

First, a fairly large content of sodium is recorded in the earth's crust. The proportion of the substance is approximately 2.6%.

Secondly, sodium and its compounds are found in large quantities in the places of evaporation of ancient seas.

Another place of accumulation of sodium and its compounds are ocean waters. Scientists have calculated that all the salt that is in the oceans is about 19 million cubic kilometers.

Sodium is also found in small amounts in living beings. The sodium content in animals is slightly higher than in plants. Sodium ions in living organisms perform the most important function: they contribute to the transmission of nerve impulses.

The use of sodium in industry

Sodium is widely used in many industries: chemical, metallurgical, nuclear, food, light and other industries.

In the chemical industry, sodium is used to produce various detergents and cleaners, fertilizers and antiseptics.

In metallurgy, sodium is used in the production of other substances such as thorium, uranium, titanium, zirconium and other compounds. Sodium acts as a reducing agent in such reactions.

Sodium is also widely used in nuclear power engineering. Sodium and its alloys are used as a coolant.

In light industry, sodium is widely used for leather processing.

Sodium is an essential element in the food industry. Sodium chloride, better known as table salt, is perhaps the most common food additive, without which the preparation of any dish is complete.

Pure sodium was obtained in 1807 by Humphry Davy, an English chemist who discovered shortly before sodium. Davy carried out the process of electrolysis of one of the compounds of sodium - hydroxide, melting which gave sodium. Sodium compounds have been used by mankind since ancient times, soda of natural origin was used in ancient Egypt (calorizator). Named element sodium (sodium) , sometimes this name can be found even now. The common name sodium (from the Latin sodium- soda) was proposed by the Swede Jens Berzelius.

Sodium is an element of group I of III of the third period of the periodic table of chemical elements of D.I. Mendeleev, has an atomic number of 11 and an atomic mass of 22.99. The accepted designation is Na(from Latin sodium).

Being in nature

Sodium compounds are found in the earth's crust, sea water, as an impurity that tends to color rock salt blue due to the action of radiation.

Sodium is a soft, ductile alkali metal that is silvery white and shiny when freshly cut (sodium can be easily cut with a knife). When pressure is applied, it turns into a transparent red substance, at ordinary temperature it crystallizes. When interacting with air, it quickly oxidizes, so it is necessary to store sodium under a layer of kerosene.

Daily requirement for sodium

Sodium is an important trace element for the human body, the daily requirement for it for adults is 550 mg, for children and adolescents - 500-1300 mg. During pregnancy, the sodium rate per day is 500 mg, and in some cases (profuse sweating, dehydration, taking diuretics) should be increased.

Sodium is found in almost all seafood (crayfish, crabs, octopuses, squid, mussels, sea kale), fish (anchovies, sardines, flounder, smelt, etc.), chicken eggs, cereals (buckwheat, rice, pearl barley, oatmeal, millet), legumes (peas, beans), vegetables (tomatoes, celery, carrots, cabbage, beets), dairy products and organ meats.

Useful properties of sodium and its effect on the body

Beneficial properties of sodium for the body are:

• Normalization of water-salt metabolism;
• Activation of enzymes of the salivary and pancreas;
• Participation in the production of gastric juice;
• Maintaining a normal acid-base balance;
• Generation of functions of the nervous and muscular system;
• Vasodilating action;
• Maintenance of osmotic concentration of blood.

Sodium absorption

Sodium is found in almost all foods, although the body receives most of it (about 80%) from. Absorption mainly occurs in the stomach and small intestine. improves sodium absorption, however, excessively salty foods and foods rich in proteins interfere with normal absorption.

Interaction with others

The use of metallic sodium is in the chemical and metallurgical industries, where it acts as the strongest reducing agent. Sodium chloride (table salt) is used by all the inhabitants of our planet without exception, it is the most famous flavoring agent and the oldest preservative.

Signs of sodium deficiency

Sodium deficiency usually occurs with excessive sweating - in hot climates or during physical exertion. Lack of sodium in the body is characterized by memory impairment and loss of appetite, dizziness, fatigue, dehydration, muscle weakness, and sometimes cramps, skin rashes, stomach cramps, nausea, and vomiting.

Signs of excess sodium

An excessive amount of sodium in the body makes itself felt by constant thirst, swelling and allergic reactions.