Sodium is oxidized by oxygen. Sodium in nature (2.6% in the Earth's crust)

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 Historical reference.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Historical reference.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.

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.

Sodium is an alkali metal. Its chemical activity is the highest among all other metals of the periodic table. That is why many chemical problems are based on the properties of this element, as well as its production.

How to get sodium: formula

Previously, sodium was obtained by reduction of sodium carbonate. To do this, coal and sodium carbonate were tightly placed in an iron container. After that, the mixture was heated to 1000 degrees:

Na 2 CO 3 + 2C -> 2Na + 3 CO

Currently, the industry uses another method for obtaining metallic sodium. For this, the electrolysis of a melt of sodium chloride is carried out.

2NaCl -> 2Na + Cl2

To obtain a melt, sodium chloride crystals must be heated to 500 - 600 degrees.

Many people are interested in how you can get sodium at home. As you can see it is possible if you can reach the melting point of common salt (sodium chloride). After that, lower two graphite electrodes into the melt and connect them to a source of direct electric current.

How to get sodium hydroxide

Sodium reacts very violently with water to form sodium hydroxide, release hydrogen, and release a lot of heat. Sodium even reacts with water vapor in the air, so metallic sodium is stored under a layer of liquid paraffin or kerosene.

2Na + 2H 2 O \u003d 2NaOH + H 2

Sodium hydroxide is widely used in industry and everyday life. This compound has other names: caustic soda, caustic alkali, caustic, technical or caustic soda.

How to get sodium oxide

Sodium is easily oxidized by atmospheric oxygen (therefore, metallic sodium is stored under a layer of kerosene) to form sodium oxide:

4Na + O 2 \u003d 2Na 2 O

Many students believe that sodium oxide can be obtained by burning sodium in oxygen. But this is not true. During combustion, sodium interacts so actively with oxygen that instead of oxide, sodium peroxide is formed:

2Na + O 2 \u003d Na 2 O 2

How to get sodium acetate

You can get sodium acetate by carrying out the neutralization reaction of sodium bicarbonate with acetic acid:

CH 3 COOH + NaHCO 3 \u003d CH 3 COONa + H 2 O + CO 2

This chemical reaction is well known to housewives; when baking various dough products, they often resort to it.

If it is necessary to obtain sodium acetate in crystalline form, then the solution obtained during the reaction is evaporated.

Thus, getting sodium acetate at home is very simple. But it's even easier to go in and buy it from a chemical store, because this substance is very cheap, and it is hardly worth messing with its independent production.

Sodium chloride: how to get

Sodium chloride can be obtained by neutralizing hydrochloric acid with sodium carbonate. During the reaction, a solution of sodium chloride in water is formed and carbon dioxide is released. If it is necessary to obtain crystalline sodium chloride, the solution obtained during the reaction is subjected to evaporation.

Na 2 CO 3 + HCl \u003d NaCl + H 2 O + CO 2

Under the name of sodium chloride, table salt is well known to all of us.

Sodium —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.

In water, sodium behaves almost the same way as lithium: the reaction proceeds with the rapid release of hydrogen, sodium hydroxide is formed in the solution.

History and origin of the name

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

Metallic sodium preserved in kerosene

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 agent.
- 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 compounds

Sodium, Natrium, Na (11)
The name sodium - sodium, natrium comes from an ancient word common in Egypt, among the ancient Greeks (vixpov) and Romans. It is found in Pliny (Nitron), in other ancient authors and corresponds to the Hebrew neter (neter). In ancient Egypt, natron, or nitron, was generally called alkali, obtained not only from natural soda lakes, but also from plant ash. It was used for washing, making glazes, and for mummifying corpses. In the Middle Ages, the name nitron (nitron, natron, nataron), as well as borah (baurach), also applied to saltpeter (Nitrum). Arab alchemists called alkalis alkali. With the discovery of gunpowder in Europe, saltpeter (Sal Petrae) began to be strictly distinguished from alkalis, and in the 17th century. already distinguished non-volatile, or fixed alkali, and volatile alkali (Alkali volatile). At the same time, a distinction was established between vegetable (Alkali fixum vegetabile - potash) and mineral alkali (Alkali fixum minerale - soda).

At the end of the XVIII century. Klaproth introduced the name natron (Natron) or sodium for mineral alkali, and for vegetable alkali - potassium (Kali), Lavoisier did not place alkalis in the “Table of Simple Bodies”, indicating in a note to it that these were probably complex substances that were once someday they will be scattered. Indeed, in 1807, Davy, by electrolysis of slightly moistened solid alkalis, obtained free metals - potassium and sodium, calling them potassium (Potassium) and sodium (Sodium). The following year, Hilbert, publisher of the famous Annals of Physics, suggested that the new metals be called potassium and sodium (Natronium); Berzelius shortened the latter name to "sodium" (Natrium). At the beginning of the XIX century. in Russia sodium was called sodium (Dvigubsky, 182i; Solovyov, 1824); Strakhov suggested the name sod (1825). Sodium salts were named, for example, soda sulphate, hydrochloric soda and at the same time acetic soda (Dvigubsky, 1828). Hess, following the example of Berzelius, introduced the name sodium.

Sodium (Latin Natrium, denoted by the symbol Na) is an element with atomic number 11 and atomic weight 22.98977. It is an element of the main subgroup of the first group, the third period of the periodic table of chemical elements of Dmitry Ivanovich Mendeleev. The simple substance sodium is soft, fusible (tmelt 97.86 ° C), ductile, light (density 0.968 g / cm3), silver-white alkali metal.

Natural sodium consists of only one isotope with a mass number of 23. In total, 15 isotopes and 2 nuclear isomers are currently known. Most artificially produced radioactive isotopes have a half-life of less than a minute. Only two isotopes have relatively long half-lives: positron-emitting 22Na with a half-life of 2.6 years, which is used as a source of positrons and in scientific research, and 24Na with a half-life of 15 hours, used in medicine to diagnose and treat some forms of leukemia.

Sodium in the form of various compounds has been known since ancient times. Sodium chloride (NaCl) or table salt is one of the most important vital compounds, it is believed that it became known to man in the Neolithic, that is, it turns out that mankind has been using sodium chloride for more than six thousand years! In the Old Testament, there is a mention of a substance called "neter", it was used as a detergent. Most likely - this is soda, sodium carbonate, which is found in the waters of salt lakes in Egypt.

In the 18th century, chemists already knew a large number of sodium compounds; salts of this metal were widely used in medicine and the textile industry (for dyeing fabrics and tanning leather). However, metallic sodium was obtained only in 1807 by the English chemist Humphry Davy.

The most important areas of application of sodium are nuclear power engineering, metallurgy, and the organic synthesis industry. In nuclear power engineering, sodium and its alloy with potassium are used as liquid metal coolants. In metallurgy, a number of refractory metals are obtained by the sodium metal method; by reducing KOH with sodium, potassium is isolated. In addition, sodium is used as an additive that strengthens lead alloys. In the organic synthesis industry, sodium is used in the production of many substances. Sodium acts as a catalyst in the preparation of some organic polymers. The most important sodium compounds are sodium oxide Na2O, sodium peroxide Na2O2 and sodium hydroxide NaOH. Sodium peroxide is used for bleaching fabrics, for air regeneration in isolated rooms. Sodium hydroxide is one of the most important products of the basic chemical industry. In colossal quantities, it is consumed to purify oil refinery products. In addition, sodium hydroxide is widely used in soap, paper, textile and other industries, as well as in the production of artificial fibers.

Sodium is one of the most important elements involved in the mineral metabolism of animals and humans. In the human body, sodium in the form of soluble salts (chloride, phosphate, bicarbonate) is found mainly in extracellular fluids - blood plasma, lymph, digestive juices. The osmotic pressure of blood plasma is maintained at the required level, primarily due to sodium chloride.

Symptoms of sodium deficiency are weight loss, vomiting, gas formation in the gastrointestinal tract, and impaired absorption of 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.

Biological properties

Sodium belongs to the group of macroelements, which, together with microelements, play an important role in the mineral metabolism of animals and humans. Macronutrients are found in the body in significant quantities, averaging from 0.1 to 0.9% of body weight. The content of sodium in the body of an adult is 55-60 g per 70 kg of body weight. Element number eleven is mainly contained in extracellular fluids: in the blood - 160-240 mg, in plasma - 300-350 mg, in erythrocytes - 50-130 mg. Bone tissue contains up to 180 mg of sodium, tooth enamel is much richer in this macronutrient - 250 mg. In the lungs it concentrates up to 250 mg, in the heart 185 mg of sodium. Muscle tissue contains about 75 mg of sodium.

The main function of sodium in the body of humans, animals and even plants is to maintain the water-salt balance in cells, regulate osmotic pressure and acid-base balance. For this reason, the sodium content in plant cells is quite high (about 0.01% wet weight), sodium creates a high osmotic pressure in the cell sap and thus helps to extract water from the soil. In humans and animals, sodium is responsible for the normalization of neuromuscular activity (participates in the normal conduction of nerve impulses) and retains the necessary minerals in the blood in a dissolved state. In general, the role of sodium in the regulation of metabolism is much wider, because this element is necessary for the normal growth and condition of the body. Sodium plays the role of a "courier", delivering various substances to each cell, for example, blood sugar. It prevents the occurrence of heat or sunstroke, and also has a pronounced vasodilating effect.

Sodium actively interacts with other elements, so together with chlorine they prevent the leakage of fluid from blood vessels into adjacent tissues. However, the main "partner" of sodium is potassium, in cooperation with which they perform most of the above functions. The optimal daily dose of sodium for children is from 600 to 1,700 milligrams, for adults from 1,200 to 2,300 milligrams. In table salt equivalent (the most popular and affordable source of sodium), this corresponds to 3-6 grams per day (100 grams of table salt contains 40 grams of sodium). The daily requirement for sodium mainly depends on the amount of salts lost with sweat, and can reach up to 10 grams of NaCl. Sodium is found in almost all foods (a significant amount in rye bread, chicken eggs, hard cheese, beef and milk), but the body receives most of it from table salt. Assimilation of the eleventh element occurs mainly in the stomach and small intestine, vitamin D contributes to better absorption of sodium. At the same time, food rich in protein and especially salty can lead to difficulty in absorption. The concentration of sodium ions in the body is regulated mainly by the hormone of the adrenal cortex - aldosterone, the kidneys either retain or release sodium, depending on whether a person abuses or receives less sodium. For this reason, under normal external conditions and proper functioning of the kidneys, neither deficiency nor surplus of sodium can occur. The lack of this element can occur with a number of vegetarian diets. In addition, heavy sodium losses with sweat are experienced by people in heavy physical occupations and athletes. Sodium deficiency is also possible with various poisonings, accompanied by profuse sweating, vomiting, and diarrhea. However, this imbalance can be easily filled with mineral water, from which the body receives not only sodium, but also a certain amount of other mineral salts (potassium, chlorine and lithium).

With a lack of sodium (hyponatremia), symptoms such as loss of appetite, decreased taste sensations, stomach cramps, nausea, vomiting, gas formation occur, as a result of all this - severe weight loss. Prolonged deficiency causes muscle cramps and neuralgia: the patient may experience difficulty balancing when walking, dizziness and fatigue, and shock may occur. Symptoms of sodium deficiency also include memory problems, sudden mood changes, and depression.

An excess of sodium causes water retention in the body, as a result - an increase in blood density, therefore, an increase in blood pressure (hypertension), edema and vascular disease. In addition, excess sodium leads to 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!

In medicine, a large number of sodium preparations are used, the most commonly used are sodium sulfate, chloride (for blood loss, fluid loss, vomiting); thiosulfate Na2S2O3∙5H2O (anti-inflammatory and antitoxic agent); borate Na2B4O7∙10H2O (antiseptic); bicarbonate NaHCO3 (as an expectorant, as well as for washing and rinsing with rhinitis, laryngitis).

Table salt - an indispensable and valuable seasoning for food was known in ancient times. Today, sodium chloride is a cheap product, together with coal, limestone and sulfur, it is one of the so-called "big four" minerals, the most important for the chemical industry. But there were times when salt was equal in price to gold. So, for example, in ancient Rome, legionnaires were often paid salaries not with money, but with salt, hence the word soldier came from. Salt was delivered to Kievan Rus from the Carpathian region, as well as from salt lakes and estuaries of the Black and Azov Seas. Its extraction and delivery was so expensive that at solemn feasts it was served on the tables of only noble guests, while the rest dispersed "not salty slurping." Even after the annexation of the Astrakhan kingdom with its salt-bearing lakes of the Caspian Sea to Rus', the price of salt did not decrease, which caused discontent among the poorest segments of the population, which escalated into an uprising known as the Salt Riot (1648). Peter I in 1711 introduced a monopoly on the trade in salt as a strategically important raw material, the exclusive right to trade in salt for the state lasted until 1862. Until now, the ancient tradition has been preserved to meet guests with “bread and salt”, which meant sharing the most expensive thing in the house.

Everyone knows the expression: “To know a person, you need to eat a pound of salt with him,” but few people thought about the meaning of this phrase. It is estimated that a person consumes up to 8 kilograms of sodium chloride per year. It turns out that the popular expression implies only one year - after all, a pood of salt (16 kg) together can be eaten during this period.

The electrical conductivity of sodium is three times lower than that of copper. However, sodium is nine times lighter, so sodium wires, if they existed, would be cheaper than copper wires. True, there are sodium-filled steel bars designed for high currents.

It is estimated that rock salt in an amount equivalent to the content of sodium chloride in the oceans would occupy a volume of 19 million cubic meters. km (50% more than the total volume of the North American continent above sea level). A prism of this volume with a base area of ​​1 km2 can reach the Moon 47 times! Salt extracted from sea waters could cover the entire land of the globe with a layer of 130 m! Now the total production of sodium chloride from sea water has reached 6-7 million tons per year, which is about a third of the total world production.

When sodium peroxide interacts with carbon dioxide, a process occurs that is reverse to breathing:

2Na2O2 + 2CO2 → 2Na2CO3 + O2

During the reaction, carbon dioxide is bound and oxygen is released. This reaction has found application in submarines for air regeneration.

An interesting fact was established by Canadian scientists. They found that in short-tempered and irritable people, sodium is quickly excreted from the body. In calm and friendly people, as well as in those who experience positive emotions, for example, in lovers, this substance is absorbed well.

With the help of sodium, on January 3, 1959, an artificial comet was created at a distance of 113 thousand km from the Earth by throwing sodium vapor into the world space from a Soviet spacecraft flying to the Moon. The bright glow of the sodium comet made it possible to refine the trajectory of the first aircraft that passed along the Earth-Moon route.

High sodium sources include refined sea salt, quality soy sauces, various pickles, sauerkraut, and meat broths. In a small amount, the eleventh element is present in seaweed, oysters, crabs, fresh carrots and beets, chicory, celery and dandelion.

Story

Natural sodium compounds - table salt NaCl and soda Na2CO3 - have been known to man since ancient times. The ancient Egyptians used natural soda, extracted from the waters of soda lakes, for embalming, bleaching canvas, cooking food, making paints and glazes. The Egyptians called this compound neter, however, this term referred not only to natural soda, but also to alkali in general, including that obtained from plant ash. Later Greek (Aristotle, Dioscorides) and Roman (Plutarch) sources also mention this substance, but already under the name "nitron". The ancient Roman historian Pliny the Elder wrote that in the Nile Delta, soda (he calls it "nitrum") was isolated from river water, in the form of large pieces it went on sale. Having a large amount of impurities, primarily coal, such soda had a gray, and sometimes even black color. In medieval Arabic literature, the term "natron" appears, from which gradually in the XVII-XVIII centuries. the term "natra" is formed, that is, the base from which table salt can be obtained. From "natra" came the modern name of the element.

The modern abbreviation "Na" and the Latin word "natrium" were first used in 1811 by Jens Jakob Berzelius, an academician and founder of the Swedish Society of Physicians, to designate natural mineral salts, which included soda. This new term replaced the original name "sodium", which was given to the metal by the English chemist Humphry Davy, who was the first to obtain metallic sodium. It is believed that Devi was guided by the Latin name of soda - “soda”, although there is another assumption: in Arabic there is the word “suda”, which means headache, in ancient times this ailment was treated with soda. It should be noted that in a number of Western European countries (Great Britain, France, Italy), as well as in the United States of America, sodium is called sodium.

Despite the fact that sodium compounds have been known for a very long time, it was only possible to obtain the metal in its pure form in 1807, by the English chemist Humphry Davy as a result of the electrolysis of slightly moistened solid sodium hydroxide NaOH. The fact is that sodium could not be obtained by traditional chemical methods - due to the high activity of the metal, while Davy's method was ahead of the scientific thought and technical developments of that time. At the beginning of the 19th century, the only really applicable and suitable source of current was a voltaic column. The one Davy used had 250 pairs of copper and zinc plates. The process described by D.I. Mendeleev in one of his works, was extremely complex and energy-intensive: “Connecting a piece of wet (to achieve galvanic conductivity) caustic soda to the positive (from copper or coal) pole and gouging a recess in it, into which mercury was poured, connected to the negative pole ( cathode) of a strong voltaic column, Davy noticed that in mercury, when a current is passed, a special metal is dissolved, less volatile than mercury, and capable of decomposing water, again forming caustic soda. Due to the high energy intensity, the alkaline method gained industrial distribution only at the end of the 19th century - with the advent of more advanced energy sources, and in 1924 the American engineer G. Downs fundamentally changed the process of electrolytic sodium production, replacing alkali with much cheaper table salt.

A year after Davy's discovery, Joseph Gay-Lussac and Louis Tenard obtained sodium not by electrolysis, but by reacting caustic soda with red-hot iron. Still later, St. Clair Deville developed a method by which sodium was obtained by reducing soda with coal in the presence of limestone.

Being in nature

Sodium is one of the most common elements - the sixth in terms of quantitative content in nature (of non-metals, only oxygen is more common - 49.5% and silicon - 25.3%) and the fourth among metals (only iron is more common - 5.08%, aluminum - 7 .5% and calcium - 3.39%). Its clarke (average content in the earth's crust), according to various estimates, ranges from 2.27% by weight to 2.64%. Most of this element is found in various aluminosilicates. Sodium is a typical element in the upper part of the earth's crust; this can be easily traced by the degree of metal content in various rocks. So the highest concentration of sodium - 2.77% by mass - in acidic igneous rocks (granites and a number of others), in basic rocks (basalts and the like), the average content of the eleventh element is already 1.94% by mass. The ultramafic rocks of the mantle have the lowest sodium content - only 0.57%. Poor in the eleventh element and sedimentary rocks (clays and shales) - 0.66% by weight, not rich in sodium and most soils - an average content of about 0.63%.

Due to its high reactivity, sodium occurs in nature only in the form of salts. The total number of known sodium minerals is more than two hundred. However, far from all are considered the most important, which are the main sources of obtaining this alkali metal and its compounds. It is worth mentioning halite (rock salt) NaCl, mirabilite (Glauber's salt) Na2SO4 10H2O, Chilean saltpeter NaNO3, cryolite Na3, tincal (borax) Na2B4O7∙10H2O, trona NaHCO3∙Na2CO3∙2H2O, thenardite Na2SO4, as well as natural silicates, such as albite Na , nepheline Na, containing in addition to sodium and other elements. As a result of the isomorphism of Na+ and Ca2+, which is due to the proximity of their ionic radii, sodium-calcium feldspars (plagioclases) are formed in igneous rocks.

Sodium is the main metal element in sea water, it is estimated that the waters of the World Ocean contain 1.5 1016 tons of sodium salts (the average concentration of soluble salts in the waters of the World Ocean is about 35 ppm, which is 3.5% by weight, for the share of sodium from they account for 1.07%). Such a high concentration is due to the so-called sodium cycle in nature. The fact is that this alkali metal is rather weakly retained on the continents and is actively transported by river waters to the seas and oceans. 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. Similar deposits of sodium salts in a relatively pure form exist on all continents, as a result of the evaporation of ancient seas. These processes are taking place in our time, as an example are the Salt Lake lake, located in the state of Utah (USA), Baskunchak (Russia, Akhtubinsky district), salt lakes of the Altai Territory (Russia), as well as the Dead Sea and other similar places.

Rock salt forms vast underground deposits (often hundreds of meters thick) that contain over 90% NaCl. The typical Cheshire salt deposit (the main source of sodium chloride in the UK) covers an area of ​​60 by 24 km and has a salt bed thickness of about 400 m. This deposit alone is estimated at more than 1011 tons.

In addition, sodium is an important bioelement, it is found in relatively large quantities in living organisms (on average 0.02%, mainly in the form of NaCl), and in animals it is more than in plants. The presence of sodium has been established in the solar atmosphere and interstellar space. In the upper layers of the atmosphere (at an altitude of about 80 kilometers) a layer of atomic sodium was discovered. The fact is that at such a height, oxygen, water vapor and other substances with which sodium could interact are almost completely absent.

Application

Sodium metal and its compounds are widely used in various industries. Due to its high reactivity, this alkali metal is used in metallurgy as a reducing agent for the production of metals such as niobium, titanium, hafnium, and zirconium by metallothermy. Back in the first half of the 19th century, sodium was used to isolate aluminum (from aluminum chloride), today the eleventh element and its salts are still used as a modifier in the production of some grades of cast aluminum alloys. Also, sodium is used in a lead-based alloy (0.58% Na), which is used in the manufacture of axial bearings for railway cars, the alkali metal in this alloy is a strengthening element. Sodium and its alloys with potassium are liquid coolants in nuclear reactors, because both elements have small absorption cross sections for thermal neutrons (0.49 barn for Na). In addition, these alloys have high boiling points and heat transfer coefficients and do not interact with structural materials at high temperatures developed in nuclear power reactors, thus not affecting the course of the chain reaction.

However, not only nuclear power uses sodium as a heat carrier - element No. 11 is widely used as a heat carrier for processes requiring uniform heating in the temperature range from 450 to 650 ° C - in aircraft engine valves, in truck exhaust valves, in injection molding machines for pressure. An alloy of sodium, potassium and cesium (Na 12%, K 47%, Cs 41%) has a record low melting point (only 78 ° C), for this reason it was proposed as the working fluid of ion rocket engines. In the chemical industry, sodium is used in the production of cyanide salts, synthetic detergents (detergenides), and pharmaceutical preparations. In the production of artificial rubber, sodium plays the role of a catalyst that combines butadiene molecules into a product that is not inferior in properties to the best grades of natural rubber. The NaPb compound (10% Na by mass) is used in the production of tetraethyl lead, the most effective antiknock agent. Sodium vapor is used to fill high and low pressure discharge lamps (NLVD and NLND). A sodium lamp is filled with neon and contains a small amount of metallic sodium; when such a lamp is turned on, the discharge begins in neon. The heat released during the discharge evaporates the sodium, and after a while, the red neon light is replaced by the yellow glow of sodium. Sodium lamps are powerful light sources with high efficiency (up to 70% in laboratory conditions). The high efficiency of sodium lamps made it possible to use them for lighting highways, railway stations, marinas and other large-scale objects. So, NLVD lamps of the DNaT type (Arc Sodium Tubular), which give bright yellow light, are very widely used in street lighting, the service life of such lamps is 12-24 thousand hours. In addition, there are lamps DNaS, DNaMT (Arc Sodium Matte), DNaZ (Arc Sodium Mirror) and DNaTBR (Arc Sodium Tubular Without Mercury). Sodium is used in the production of highly energy-intensive sodium-sulfur batteries. In organic synthesis, sodium is used in reduction, condensation, polymerization and other reactions. Occasionally, metallic sodium is used as a material for electrical wires designed for very high currents.

Numerous sodium compounds are no less widely used: table salt NaCl is used in the food industry; sodium hydroxide NaOH (caustic soda) is used in the soap industry, in the manufacture of paints, in the pulp and paper and oil industries, in the production of artificial fibers, and also as an electrolyte. Soda - sodium carbonate Na2CO3 is used in glass, pulp and paper, food, textile, oil and other industries. In agriculture, the sodium salt of nitric acid NaNO3, known as Chilean nitrate, is widely used as a fertilizer. Sodium chlorate NaClO3 is used to destroy unwanted vegetation on the railway track. Sodium phosphate Na3PO4 - a component of detergents, used in the production of glasses and paints, in the food industry, in photography. Sodium azide NaN3 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 the nitrocarburizing of steel and in electroplating (silver plating, gilding). Silicates mNa2O nSiO2 - charge components in the production of glass, for the production of aluminosilicate catalysts, heat-resistant, acid-resistant concretes.

Production

As is known, metallic sodium was first obtained in 1807 by the English chemist Davy by electrolysis of sodium hydroxide NaOH. From a scientific point of view, the isolation of alkali metals is a grandiose discovery in the field of chemistry. However, the industry of those years could not appreciate the significance of this event - firstly, at the beginning of the 19th century, the necessary capacities simply did not exist for the production of sodium on an industrial scale, and secondly, no one knew where soft metal could be useful, flashing during the interaction with water. And if the first difficulty in 1808 was solved by Joseph Gay-Lussac and Louis Tenard, having obtained sodium, without resorting to energy-intensive electrolysis, by means of the reaction of caustic soda with iron heated to red heat, then the second problem - the scope - was solved only in 1824 year, when aluminum was isolated with the help of sodium. In the second half of the 19th century, Saint-Clair Deville developed a new method for obtaining metallic sodium - by reducing soda with coal in the presence of limestone:

Na2CO3 + 2C → 2Na + 3CO

In 1886 this method was improved. However, already in 1890, the electrolytic method for producing sodium was introduced into industry. Thus, the idea of ​​Humphry Davy on an industrial scale was realized only 80 years later! All searches and research ended with a return to the original method. In 1924, the American engineer Downes made the process of electrolytic sodium production cheaper by replacing alkali with much cheaper table salt. This modernization affected the production of metallic sodium, which increased from 6 thousand tons (1913) to 180 thousand tons (1966). The Downs method formed the basis of the modern method for obtaining metallic sodium.

Now the main industrial method for obtaining metallic sodium is the electrolysis of sodium chloride melt (chlorine is a by-product of the process) with the addition of KCl, NaF or CaCl2, which lower the melting point of salt to 575-585 ° C. Otherwise, the electrolysis of pure sodium chloride would lead to large losses of metal from evaporation, since the melting points of NaCl (801 ° C) and the boiling points of metallic sodium (882.9 ° C) are very close. The process takes place in a steel cell with a diaphragm. The modern sodium electrolyser is an imposing structure resembling a furnace. The unit is made of refractory bricks, which is surrounded by a steel casing from the outside. A graphite anode is introduced through the bottom of the cell, surrounded by an annular mesh - a diaphragm that prevents the penetration of sodium into the anode space, where chlorine is deposited. Otherwise, sodium would simply burn out in chlorine.

The annular cathode is made of iron or copper. Caps are installed above the cathode and anode to remove sodium and chlorine. A mixture of carefully dried sodium chloride and calcium chloride is loaded into the electrolyzer, we already know that such a mixture melts at a lower temperature than pure sodium chloride. Usually the process takes place at a temperature of about 600 °C. A direct current with a voltage of about 6 V is applied to the electrodes, while the Na + ions are discharged at the cathode and metallic sodium is released, which floats up and is discharged into a special collector. Naturally, the process goes without air access. Chlorine ions Cl– are discharged at the anode and chlorine gas, a valuable by-product of sodium production, is released. During the day of operation of the electrolyzer, 400-500 kg of sodium and 600-700 kg of chlorine are produced. The metal thus obtained is purified from impurities (chlorides, oxides, etc.) by adding a mixture of NaOH + Na2CO3 + NaCl or Na2O2 to molten sodium; treatment of the melt with metal lithium, titanium or titanium-zirconium alloy, lower chlorides TiCl3, TiCl2; vacuum distillation.

Physical properties

Humphry Davy was not only the first to obtain metallic sodium, but also the first to investigate its properties. Reporting in London on the discovery of new elements (potassium and sodium), the chemist for the first time demonstrated to the scientific audience samples of new metals. An English chemist kept a piece of metallic sodium under a layer of kerosene, with which sodium did not interact and did not oxidize in its environment, retaining its brilliant silvery color. In addition, sodium (density at 20 °C is 0.968 g/cm3) is heavier than kerosene (density at 20 °C with various degrees of purification is 0.78-0.85 g/cm3) and does not float on its surface, therefore, does not oxidized by oxygen and carbon dioxide. Davy did not limit himself to the usual demonstration of a vessel with a sample of a new metal, taking sodium out of kerosene, the chemist threw the sample into a tub of water. To everyone's surprise, the metal did not sink, but began to actively move along the surface of the water, melting into small shiny droplets, some of which ignited. The fact is that the density of water (at 20 ° C is 0.998 g/cm3) is greater than the density of this alkali metal, for this reason sodium does not sink in water, but floats in it, actively interacting with it. The public was amazed at this "presentation" of the new element.

What can we now tell about the physical properties of sodium? The eleventh element of the periodic system is a soft (easily cut with a knife, pressed and rolled), light, shiny, silver-white metal that quickly tarnishes in air. Thin layers of sodium have a purple hue, under pressure the metal becomes transparent and red, like a ruby. At ordinary temperature, sodium crystallizes in a cubic lattice with the following parameters: a = 4.28 A, atomic radius 1.86 A, Na+ ionic radius 0.92 A. Sodium atom ionization potentials (eV) 5.138; 47.20; 71.8; the electronegativity of the metal is 0.9. The work function of the electrons is 2.35 eV. This modification is stable at temperatures above -222 °C. Below this temperature, the hexagonal modification is stable with the following parameters: a = 0.3767 nm, c = 0.6154 nm, z = 2.

Sodium is a low-melting metal, its melting point is only 97.86 °C. It turns out that this metal could melt in boiling water if it did not actively interact with it. Moreover, during melting, the density of sodium decreases by 2.5%, however, there is an increase in volume by ΔV = 27.82∙10-6 m3/kg. As the pressure increases, the melting point of the metal increases, reaching 242°C at 3 GPa and 335°C at 8 GPa. The boiling point of molten sodium is 883.15 ° C. The heat of vaporization of sodium at normal pressure = 3869 kJ / kg. The specific heat capacity of the eleventh element (at room temperature) is 1.23 103 J/(kg K) or 0.295 cal/(g deg); the thermal conductivity of sodium is 1.32 102 W / (m K) or 0.317 cal / (cm sec deg). The temperature coefficient of linear expansion for this alkali metal (at 20 °C) is 7.1 10-5. The electrical resistivity of sodium (at 0 °C) is 4.3 10-8 ohm m (4.3 10-6 ohm cm). During melting, the electrical resistivity of sodium increases by a factor of 1.451. Sodium is paramagnetic, its specific magnetic susceptibility is +9.2 10-6. Brinell sodium hardness HB = 0.7 MPa. Modulus of normal elasticity in tension at room temperature E = 5.3 GPa. Sodium compressibility x = 15.99∙10-11 Pa-1. Sodium is a very ductile metal, easily deformed in the cold. The sodium outflow pressure, according to N. S. Kurnakov and S. F. Zhemchuzhny, is in the range of 2.74-3.72 MPa, depending on the diameter of the outlet.

Chemical properties

In chemical compounds, including hydrides, sodium exhibits an oxidation state of + 1. The eleventh element is one of the most reactive metals, therefore it does not occur in nature in its pure form. Even at room temperature, it actively reacts with atmospheric oxygen, water vapor and carbon dioxide, forming a loose crust on the surface from a mixture of peroxide, hydroxide and carbonate. For this reason, metallic sodium is stored under a layer of dehydrated liquid (kerosene, mineral oil). Noble gases slightly dissolve in solid and liquid sodium, at 200 ° C sodium begins to absorb hydrogen, forming a very hygroscopic NaH hydride. This alkali metal reacts extremely weakly with nitrogen in a glow discharge, forming a very unstable substance - sodium nitride:

6Na + N2 → 2Na3N

Sodium nitride is stable in dry air, but decomposes immediately with water or alcohol to form ammonia.

With direct interaction of sodium with oxygen, depending on the conditions, oxide Na2O is formed (when sodium is burned in an insufficient amount of oxygen) or peroxide Na2O2 (when sodium is burned in air or in excess oxygen). Sodium oxide exhibits pronounced basic properties, reacts violently with water to form NaOH hydroxide, a strong base:

Na2O + H2O → 2NaOH

Sodium hydroxide is a highly soluble alkali in water (108 g of NaOH dissolves in 100 g of water at 20 ° C) in the form of solid white hygroscopic crystals, corrodes skin, fabrics, paper and other organic substances. When dissolved in water, it releases a large amount of heat. In air, sodium hydroxide actively absorbs carbon dioxide and turns into sodium carbonate:

2NaOH + CO2 → Na2CO3 + H2O

For this reason, sodium hydroxide must be stored in sealed containers. In industry, NaOH is obtained by electrolysis of aqueous solutions of NaCl or Na2CO3 using ion-exchange membranes and diaphragms:

2NaCl + 2H2O → 2NaOH + Cl2 + H2

Sodium peroxide is a pale yellow powder that melts without decomposition, Na2O2 is a very strong oxidizing agent. Most organic substances ignite when in contact with it. When Na2O2 reacts with carbon dioxide, oxygen is released:

2Na2O2 + 2CO2 → 2Na2CO3 + O2

Metallic sodium, like its oxides, actively interacts with water to form NaOH hydroxide and release hydrogen, with a large contact surface, the reaction proceeds with an explosion. Sodium reacts much more calmly with alcohols than with water, resulting in sodium alcoholate. So, reacting with ethanol, sodium gives sodium ethanolate C2H5ONa:

2Na + 2C2H5OH → 2C2H5ONa + H2

Sodium dissolves in almost all acids with the formation of a large number of salts:

2Nа + 2НCl → 2NаСl + Н2

2Na + 2Н2SO4 → SO2 + Na2SO4 + 2H2O

In an atmosphere of fluorine and chlorine, sodium ignites spontaneously, reacts with bromine when heated, and there is no direct interaction with iodine. It reacts violently with sulfur, when ground in a mortar, forming sulfides of variable composition. Sodium sulfide Na2S is obtained by reduction of sodium sulfate with carbon. A very common compound of sodium with sulfur and oxygen is the so-called Glauber's salt Na2SO4∙10H2O. In addition to sulfur, it actively reacts with selenium and tellurium to form chalcogenides of the compositions Na2X, NaX, NaX2, Na2X5.

Sodium dissolves in liquid ammonia (34.6 g per 100 g NH3 at 0°C) to form ammonia complexes (a blue color solution with metallic conductivity). When ammonia evaporates, the original metal remains; during long-term storage of the solution, it gradually discolors due to the reaction of the metal with ammonia to form NaNH2 amide or Na2NH imide and release hydrogen. When gaseous ammonia is passed through molten sodium at 300-350 °C, sodiumamine NaNH2 is formed - a colorless crystalline substance that is easily decomposed by water.

At 800-900 °C, gaseous sodium with carbon forms carbide (acetylenide) Na2C2. Sodium forms inclusion compounds with graphite.

Sodium forms a number of intermetallic compounds - with silver, gold, tin, lead, bismuth, cesium, potassium and other metals. Does not form compounds with barium, strontium, magnesium, lithium, zinc and aluminum. With mercury, sodium forms amalgams - intermetallics of the composition NaHg2, NaHg4, NaHg8, NaHg, Na3Hg2, Na5Hg2, Na3Hg. Significant liquid amalgams (containing less than 2.5% by weight of sodium), obtained by the gradual introduction of sodium into mercury, which is under a layer of kerosene or mineral oil.

A huge number of organosodium compounds are known, similar in chemical properties to organolithium compounds, but superior to them in reactivity.