Sodium is one of 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 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, you can get (kitchen salt), sodium iodide, which is used in the manufacture of metal halide lamps, sodium bromide, used as medicinal product with neurosis, 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 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 kind of biological characteristic 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, 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. Also it can 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 (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 a relatively long half-life: 22Na, which emits positrons 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 for the diagnosis and treatment of certain forms of leukemia.

Sodium in the form of various compounds has been known since ancient times. Sodium chloride (NaCl) or salt- 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 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 uses of sodium are nuclear power, metallurgy, 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 connections sodium - 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 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 macronutrients, which, together with microelements, play 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 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 maintains the necessary minerals dissolved in the blood. In general, the role of sodium in the regulation of metabolism is much wider, because this element is necessary for normal growth and state 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 blood pressure(hypertension), edema and vascular disease. In addition, excess sodium leads to increased excretion of potassium in the urine. Maximum amount salt, which can be processed by the kidneys is approximately 20-30 grams, large quantity 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 back 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 in money, but in salt, hence the word soldier. IN Kievan Rus salt was delivered from the Carpathian region, as well as from salt lakes and estuaries of the Black and Seas of Azov. 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. Still preserved ancient tradition to meet guests with "bread and salt", which meant sharing the most precious 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 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 whole land the globe 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 benevolent 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, passing along the route Earth - Moon.

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 sea ​​kale, 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 Davy was guided by the Latin name for soda - "soda", although there is another assumption: in Arabic there is a word "suda", meaning 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, Davy's method was ahead of scientific thought and technical developments that time. IN early XIX century, the only really applicable and suitable source of current was the 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 still taking place in our time, an example is the Salt Lake lake, located in the state of Utah (USA), Baskunchak (Russia, Akhtubinsky district), salt lakes 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 ionic 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 connects butadiene molecules into a product that is not inferior in properties to the best varieties 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 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 when aluminum was isolated with 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 ​​Humphrey 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 Downes method was the basis modern way 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 say about physical properties 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. Specific heat the eleventh element (at room temperature) 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. Specific electrical resistance 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 among 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 to form a large number 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 (solution of blue color, which has 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, sodium amine NaNH2 is formed - colorless crystalline substance 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.

Known great amount organosodium compounds similar in chemical properties to organolithium compounds, but superior to them in reactivity.

-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

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

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 qualitative analysis 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 belongs to the category of alkali metals. The element belongs to the third period and to the first group of the periodic system of Mendeleev.

Physical and chemical properties of sodium

In its pure form, sodium is a gray substance with a metallic luster and low hardness. The metal is so soft that it can be easily cut with a knife. The melting point of sodium is 79 °C. The density of the metal is 0.97 g/cm³.


Fresh Cut Sodium

Sodium has a high activity and is able to react violently with many other substances. The molar mass of the metal is 23. Due to the high activity of sodium and its inherent characteristics, sodium oxide is able to form alkali.

Sodium is used in the chemical industry: the alkali metal is needed to produce sodium hydroxide, sodium fluoride, sulfates and nitrates. The metal is used as a strong reducing agent for the isolation of pure metals from their salts (there is a special technical sodium for this).

Sodium is used in the pharmaceutical industry to produce sodium bromide, one of the main components of many antidepressants and sedatives. Sodium is also used in the manufacture of gas discharge lamps. Sodium chlorate (NaClO₃) is used to remove plants and weeds from railway. With the help of sodium cyanide, precious metal is obtained from rocks.

Interaction with acids and salts

Sodium reacts with all acids, forming a sodium salt and. When an alkali metal reacts with hydrochloric acid, sodium chloride and hydrogen are formed. Reaction equation:

Na + HCl = NaCl + H₂


Molecular structure of sodium chloride

This chemical interaction is a substitution reaction. This reaction helps to obtain such salts: nitrate, phosphate, sulfate, nitrite, sodium carbonate, sulfite. You can conduct many interesting experiments with C, for example, to study the chain of transformations of copper compounds: from blue copper sulfate you get greenish -, then turquoise (CuOH)₂CO₃, black CuO and finally blue-purple ²⁺, and the latter again forms copper sulfate CuSO₄! Click here to find out how to experience this extraordinary experience.

Sodium reacts with salts of all metals except potassium and calcium (they are more reactive). As a result of the interaction of sodium with metal salts, a substitution reaction occurs. Sodium atoms take the place of atoms of a chemically less active metal. When mixing 2 moles of sodium and 1 mole of magnesium nitrate, 2 moles of sodium nitrate and 1 mole of pure magnesium are formed. Reaction equation:

2Na + Mg(NO₃)₂ = 2NaNO₃ + Mg.

Interaction with halogens

Halogens are simple substances belonging to the seventh group of the periodic system of Mendeleev: iodine, fluorine, bromine, chlorine. Sodium reacts with all elements, forming sodium iodide, fluoride, bromide and sodium chloride. To carry out the reaction, 1 mole of fluorine is added to 2 moles of sodium. As a result, 2 moles of sodium fluoride are formed. Reaction equation:

Na + F₂ = 2NaF

The resulting sodium fluoride is used in the production of detergents and anti-caries toothpastes. By the same method, when chlorine is added, sodium chloride (kitchen salt), sodium iodide, and sodium bromide are obtained.

The interaction of sodium with simple substances

Sodium reacts with sulfur, carbon, phosphorus. These chemical interactions take place high temperature. An addition reaction occurs, with the help of which sodium sulfide, sodium phosphide, sodium carbide are formed. For example, the addition of sodium atoms to phosphorus atoms: if 1 mole of phosphorus is added to 3 moles of sodium and then heated, 1 mole of sodium phosphide is formed. Reaction equation:

3Na + P = Na₃P

Sodium reacts with nitrogen and hydrogen. The reaction of nitrogen with sodium produces sodium nitride, and the reaction of hydrogen with sodium produces sodium hydride. Reaction equations:

6Na + N₂ = 2Na₃N

2Na + Н₂ = 2NaH

For the first reaction, an electrical discharge is required, for the second, a high temperature.

Formation of sodium oxides

The reaction of the metal with leads to the formation of an oxide: 1 mole of oxygen is consumed to burn 4 moles of sodium and 2 moles of sodium oxide are formed. The formula of sodium oxide is Na₂O. Reaction equation:

4Na + О₂ = 2Na₂O

When water is added to sodium oxide, an alkali is formed - NaOH. Taking 1 mole of oxide and 1 mole of water, we get 2 moles of base. Reaction equation:

Na₂O + Н₂О = 2NaOH


Flakes of caustic soda (NaOH)

Due to the pronounced alkaline properties and high chemical activity, this substance is called.

Caustic sodium, like all strong acids, actively reacts with organic compounds, salts of low-active metals and other substances. During the interaction of caustic sodium with salts, an exchange reaction occurs - a new salt and a new base are formed. A solution of caustic sodium is capable of destroying paper, fabric, skin, nails, therefore, when working with the substance, it is necessary to adhere to safety regulations.

Reaction of sodium with water

Under laboratory conditions, this is carried out: a piece of sodium is removed from kerosene with tweezers, placed on dry filter paper lying on glass or ceramic tile. The metal is dried with filter paper. Holding the sodium with tweezers, the top layer is cut off with a knife, exposing its clean surface with a characteristic metallic sheen. Next, you need to separate a piece of metal (smaller than a pea) with a knife, and place the remaining metal in a vessel with kerosene. Transfer the cut piece of metal to water and cover with a test tube with a perforated bottom. Bring a lit splinter to the hole. Attention! Do not try this at home or on your own! During the reaction, a gas is released - hydrogen. In addition, alkali is another product of the reaction.

To the question what is the mass of a sodium molecule, if possible with a solution)) given by the author Behemoth the best answer is I look at you a bunch of incomprehensible information dumped, but nothing on the case. I'll write to the point.
Given:
one molecule of sodium. The molecular weight of sodium is 11 a.u. e. m. (from the periodic table). The molar mass is _numerically_ equal to the molecular mass and for sodium is M = 11 g/mol.
Find:
mass of one molecule of sodium
Solution:
Let's discuss. What is molar mass? This is the mass of (one) mole of a substance. Here the molar mass of sodium is 11 g/mol. What is a mole? This is the amount of a substance that contains Na (Avogadro's Number) molecules. The Avogadro number is equal to Na = 6.02*10^23, the dimension is mol^-1.
Thus we get
6.02*10^23 molecules (1 mole) of sodium weigh 11 grams
1 molecule of sodium weighs X grams
Can you figure out proportions? It turns out that X = 11/(6.02*10^23) = 1.827*10^(-23) grams.
There is another way to count. To do this, remember that a mole is the amount of a substance that contains as many molecules (or atoms) as there are atoms in 12 grams of (exactly) pure carbon-12 isotope. That is, knowing how much a carbon atom weighs in grams, how much a mole of sodium weighs (the molar mass of sodium is 11 g / mol), you can calculate the mass of a sodium molecule.
There is one small problem here. The fact is that in different books and problem books different masses of the carbon atom are given. Apparently, they can’t agree on how much he weighs with us. According to one source - 1.66 * 10 ^ (-24) grams, according to another - 1.993 * 10 ^ (-23) grams. So
mass of sodium = molecular weight of sodium * 1/12 * 1.66 * 10^(-24) grams or
mass of sodium = molecular weight of sodium * 1/12 * 1.993*10^(-23) grams
In numbers
m = 11 * 1/12 * 1.66 *10^(-24) = 1.522*10^(-24) grams or
m = 11 * 1/12 * 1.993*10^(-23) = 1.827*10^(-23) grams.
The second result completely coincides with that obtained above. So the mass of a carbon atom is still 1.993*10^(-23). 🙂
Answer: The mass of a sodium molecule is 1.827*10^(-23) grams.
Phew. Chemistry is power! Teach, understand, in life it may not be useful, but you will learn to think, reason and count.
Source: school

Answer from 22 answers[guru]

Hello! Here is a selection of topics with answers to your question: what is the mass of a sodium molecule, if possible with a solution))

Answer from Staff[guru]
AVOGADRO NUMBER, NA \u003d (6.022045 ± 0.000031) × 1023, the number of molecules in a mole of any substance or the number of atoms in a mole a simple substance. One of the fundamental constants, with which you can determine such quantities as, for example, the mass of an atom or molecule (see below), the charge of an electron, etc.
Mole - the amount of a substance that contains as many structural elements as there are atoms in 12 g of 12C, and the structural elements are usually atoms, molecules, ions, etc. The mass of 1 mol of a substance, expressed in grams, is numerically equal to its mol. mass. Thus, 1 mole of sodium has a mass of 22.9898 g and contains 6.02 × 1023 atoms;


Answer from H J[active]
NATRIUM (lat. Natrium, from Arabic natrun, Greek nitron - natural soda), Na (read "sodium"), a chemical element with atomic number 11, atomic mass 22.98977. One stable isotope, 23Na, is found in nature. Belongs to the number of alkali metals. It is located in the third period in group IA in the periodic table of elements. The configuration of the outer electron layer is 3 s1. The oxidation state is +1 (valency I).
Atomic radius 0.192 nm, Na + ion radius 0.116 nm (coordination number 6). Sequential ionization energies 5.139 and 47.304 eV. Pauling electronegativity 1.00.
So the molecular weight of Na is 22.98977 or 23