The amount of energy that sodium reacts with water. Sodium characteristic

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

In water, sodium behaves in almost the same way as lithium: the reaction proceeds with a violent evolution 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), which occurs naturally in the waters of the natron 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 (there was a sufficient proportion of impurities in it) was isolated from river water... She 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 Humphrey 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 previously called Sodium.

Receiving

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 up to 1000 ° C:

Na 2 CO 3 + 2C = 2Na + 3CO

Then another method of producing sodium appeared - electrolysis of a molten sodium hydroxide or sodium chloride.

Physical properties

Metallic sodium stored in kerosene

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

Sodium is a silvery-white metal, in thin layers with a purple tint, plastic, even soft (easily cut with a knife), a fresh cut of sodium glistens. The 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, and the boiling point is 883.15 ° C.

Chemical properties

Alkali metal, easily oxidized in air. To protect against oxygen in the air, metallic sodium is stored under a layer 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 = 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 manufacture 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.

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

Sodium is also used in high and low pressure discharge lamps (HLP and LHP). NLVD lamps of the DNaT type (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 Matt), DNaZ (Arc Sodium Mirror) and DNaTBR (Arc Sodium Tubular Without Mercury).

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

- Sodium chloride (table salt) - the oldest used flavoring and preserving 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 the nitrocarburizing of steel and in electroplating (silvering, gilding).
- Sodium chlorate (NaClO 3) is used to destroy unwanted vegetation on railway tracks.

Biological role

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

Together withpotassiumsodium has the following functions:
Creation of conditions for the emergence of membrane potential and muscle contractions.
Maintaining the osmotic concentration of the blood.
Maintaining acid-base balance.
Water balance normalization.
Providing 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 sodium absorption, however, excessively salty and protein-rich foods interfere with normal absorption. The amount of sodium ingested with food shows the sodium content in the urine. Foods rich in sodium are characterized by accelerated excretion.

Eating sodium deficiency balanced food humans do not occur, however, some problems may arise with vegetarian diets. Temporary deficiency can be caused by the use of diuretics, diarrhea, profuse sweating, or excess water intake. Symptoms of sodium deficiency include weight loss, vomiting, gas in the gastrointestinal tract, and impaired absorption. 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 increased excretion of potassium in the urine. The maximum amount of salt that can be processed by the kidneys is about 20-30 grams, a larger amount is already life-threatening.

Sodium compounds

Sodium, Natrium, Na (11)
The name sodium - sodium, natrium comes from ancient word common in Egypt, among the ancient Greeks (vixpov) and the 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 mummifying corpses. In the Middle Ages, the name nitron (nitron, natron, nataron), as well as borach (baurach), also referred to saltpeter (Nitrum). Arab alchemists called alkali 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 between non-volatile, or fixed alkalis, and volatile alkali (Alkali volatile). At the same time, a distinction was made between vegetable (Alkali fixum vegetabile - potash) and mineral alkali (Alkali fixum minerale - soda).

At the end of the 18th century. Klaproth introduced the name Natron for mineral alkali (Natron), or sodium and for vegetable alkali (Kali), Lavoisier did not place alkali in the "Table of Simple Bodies", indicating in a note to it that these are probably complex substances that when- something will be decomposed. Indeed, in 1807 Davy, by electrolysis of slightly moistened solid alkalis, obtained free metals - potassium and sodium, calling them Potassium and Sodium. The following year, Hilbert, publisher of the famous Annals of Physics, proposed calling the new metals potassium and sodium (Natronium); Berzelius abbreviated the latter name to "sodium" (Natrium). At the beginning of the XIX century. in Russia sodium was called sodium (Dvigubsky, 182i; Soloviev, 1824); Strakhov proposed the name Sod (1825). Sodium salts were called, for example, sulphate soda, hydrochloric soda and at the same time acetic soda (Dvigubsky, 1828). Hess, following the example of Berzelius, introduced the name sodium.

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

Physical properties

This section will discuss the characteristics of sodium from the point of view of physics. To begin with, in its pure form it is a silvery solid with a metallic luster and low hardness. The 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 characteristics of sodium

This element has a very high activity - it is able to react quickly and violently 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 the amount of a substance that contains 6.02 x 10 to the 23rd power of atoms (molecules if the substance is complex). Knowing molar mass element, you can determine how much a specific amount of a mole of a given substance will weigh. For example, two moles of sodium weighs forty-six grams. As mentioned above, this metal is one of the most chemically active, it belongs to alkaline, 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 the oxide. For example, if you burn four moles of sodium, we spend one mole of oxygen and get two moles of this metal oxide. The formula for sodium oxide is Na 2 O. The reaction equation looks like this: 4Na + O 2 = 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 the 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 inactive metals, organic compounds, etc. During interaction with salts, an exchange reaction occurs - a new salt and a new base are formed. A caustic sodium solution can easily destroy fabric, paper, skin, nails, so it requires compliance with safety rules 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 composed of chemical elements that belong to the seventh group of the periodic table. Their list includes fluorine, iodine, chlorine, bromine. Sodium is able to react with all of them, forming 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 get sodium fluoride in an amount of two moles. This process can be written as an equation: Na + F 2 = 2NaF. The sodium fluoride we obtained is used in the production of toothpastes against caries, as well as detergents for various surfaces. Similarly, with the addition of chlorine, it is possible to obtain (kitchen salt), sodium iodide, which is used in the manufacture of metal halide lamps, sodium bromide, used as a medicine for neuroses, insomnia, hysteria and other disorders of the nervous system.

With other simple substances

Reactions of sodium with phosphorus, sulfur (sulfur), carbon (carbon) are also possible. Such chemical interactions can be carried out only if special conditions are created in the form high temperature... Thus, the addition reaction takes place. It can be used to obtain 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, a nitride of this metal is formed, in the second, a hydride. The following equations of chemical reactions can be cited as examples: 6Na + N2 = 2Na 3 N; 2Na + H2 = 2NaH. To carry out the first interaction, an electric discharge is required, the second, a high temperature.

Reactions with acids

The characteristic 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 = NaCl + H 2. This kind of chemical interaction is called a substitution reaction. Using it, you can also obtain salts such as phosphate, nitrate, nitrite, sulfate, sulfite, sodium carbonate.

6interaction with salts

Sodium reacts with salts of all metals, except for potassium and calcium (they are more reactive than the element in question). In a similar 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, as well as pure magnesium - one mole. You can write the equation for this reaction as follows: 2Na + Mg (NO 3) 2 = 2NaNO 3 + Mg. Many other sodium salts can be prepared in the same way. 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 abundant substances on the planet. And with it, the metal in question is also capable of entering into chemical interaction. In this case, the already discussed above caustic sodium, or sodium hydroxide, 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 constituents of the animal cell. Here it performs important functions: together with potassium, it supports it participates in the formation and propagation of nerve impulses between cells, 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, glucose transport through the blood, which is so necessary for the functioning of the brain, is impossible. This metal also takes part in the process of muscle contraction.

This microelement is needed not only by animals - sodium also performs important functions in the plant body: 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.

Excess and deficiency of 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 may be an increase in body temperature, swelling, increased nervous excitability, and impaired renal function. If such symptoms appear, you need to remove kitchen salt and foods that contain a lot of this metal from the diet (the list will be given below), and then immediately consult a doctor. Low sodium levels in the body also lead to unpleasant symptoms and organ dysfunction. Washed out given chemical element can with prolonged use of diuretics or when drinking only purified (distilled) water, with increased sweating and dehydration. Symptoms of sodium deficiency are thirst, dry skin and mucous membranes, vomiting and nausea, poor appetite, impaired consciousness and apathy, tachycardia, and cessation of full kidney function.

Foods high in sodium

In order to avoid too high or too low content in the body of the chemical element in question, you need to know which food contains the most of it. First of all, this is the kitchen salt already mentioned above. It is forty percent sodium. It can also be sea salt. In addition, this metal is found in soy and soy sauce. A large amount of sodium is found in seafood. These are seaweed, most fish species, shrimps, octopuses, crab meat, caviar, crayfish, etc. The sodium content in them is due to the fact that these organisms live in a salty environment with high concentration 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 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 powerful reducing agent - to separate pure metals from their salts. There is a special technical sodium for this purpose. Its properties are recorded in GOST 3273-75. Due to the above-mentioned strong reducing properties, sodium is widely used in metallurgy.

Also, this chemical element finds its use in the famaceous industry, where it is most often required 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 them from railway tracks to prevent overgrowing of the latter. Sodium cyanide is 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 are formed, sodium and foul gas. When one mole of sodium carbonate interacts with two moles of carbon, two moles of the desired metal and three moles of carbon monoxide are obtained. The equation of the given reaction can be written as follows: NaCO 3 + 2C = 2Na + 3CO. In a similar way, 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. Qualitative response the sodium ion is incinerated - if present, the flame will turn yellow.

Where can you find the chemical element in question 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 found in some minerals. This is, for example, 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 an inhomogeneous structure with alternating colored parts; orange, pink, blue, and 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 transparent. It has a dim shine, the rays of light are strongly refracted in it. These two minerals serve as raw materials for obtaining the metals that are part of their composition: sodium, potassium, magnesium.

Scientists believe that the metal that we have considered in this article is one of the most abundant in nature, since it is earth crust is two and a half percent.

Natron was originally called sodium hydroxide. In 1807, Davy, by electrolysis of slightly moistened solid alkalis, obtained free metals - potassium and sodium, calling them Potassium and Sodium. Berzelius, and then Hess in Russia proposed the name Natrium / Sodium, which stuck.

Being in nature, getting:

In nature, free alkali metals are not found. Sodium is found in various compounds. The most important is the combination of sodium with chlorine NaCl, which forms rock salt deposits (Donbass, Solikamsk, Sol-Iletsk, etc.). Sodium chloride is also found in seawater and salt springs. Sodium is one of the common elements. The sodium content in the earth's crust is 2.64%.
Obtained by electrolysis of molten sodium chloride or sodium hydroxide. Also used is the reduction of its oxides, chlorides, carbonates with aluminum, silicon, calcium, magnesium when heated in a vacuum.

Physical properties:

Sodium is a silvery-white metal, its density is 0.97 g / cm 3, very soft, easily cut with a knife. There is a metallic bond between atoms. A substance with such a bond is characterized by a metallic luster, plasticity, softness, good electrical conductivity and thermal conductivity.

Chemical properties:

The sodium atom during chemical interaction easily gives up valence electrons, passing into a positively charged ion. It quickly oxidizes in air, so it is stored under a layer of kerosene.
When burned in excess oxygen forms sodium peroxide, Na 2 O 2
With hydrogen, when heated, forms hydride Na + H 2 = 2NaH
Easily interacts with many non-metals - halogens, sulfur, phosphorus, etc.
Reacts violently with water: 2Na + 2H 2 O = 2NaOH + H 2

The most important connections:

Sodium oxide, Na 2 O (colorless), reacts with water vapor, carbon dioxide, therefore it is better to store in anhydrous benzene.
The direct reaction of sodium with oxygen produces a mixture of sodium oxide and sodium peroxide. To obtain pure oxide, you can use the reaction: Na 2 O 2 + 2Na = 2Na 2 O
Sodium peroxide, Na 2 O 2 (yellow) crystalline substance with an ionic lattice, interacts with moist air carbon dioxide, releasing oxygen: 2Na 2 O 2 + 2CO 2 = 2Na 2 CO 3 + O 2
Sodium hydroxide, NaOH is a crystalline white substance, relatively low-melting, very thermally stable. Evaporates when heated without losing water. It dissolves well in water, in alcohols.
Sodium halides, colorless crystalline substances, readily soluble in water, with the exception of NaF. They are characterized by restorative properties.
Sodium sulfide, - Na 2 S. Colorless crystalline substance with an ionic lattice. Well soluble in water, it is a strong reducing agent.
Salt, all salts are highly soluble and strong electrolytes.
Sodium hydride, NaH is a colorless crystalline substance with a crystal lattice of the NaCl type, the anion is H -. Obtained by passing hydrogen over molten metal. Undergoes thermal dissociation without melting, easily decomposed by water:
2NaH = 2Na + H 2
NaH + H 2 O = NaOH + H 2

Application:

Sodium compounds are the most important components of chemical production. Used in soap making, glass production, household chemicals.
Sodium is essential for most life forms, including humans. In living organisms, sodium ions, together with potassium ions, function as transmitters of nerve impulses. Also its ions play important role in maintaining the water regime of the body.

Bondareva Maria Alexandrovna
KhF Tyumen State University, group 561.

Sources: G.P. Khomchenko "A manual on chemistry for applicants to universities"
"Inorganic chemistry in schemes and tables"

After all this, is it any wonder that sodium production continues to rise?

We end our story about element number 11 with the words of Dmitri Ivanovich Mendeleev, written many years ago, but doubly true for our days: correct concept about simple bodies, but especially because in sodium one can see chemical properties, only weakly expressed in other well-known metals. "

Detailed story about chemical properties ah sodium is omitted for the reason that it is one of the few sections of chemistry that is sufficiently fully described in school textbooks.

• SODIUM ON A SUBMARINE. Na melts at 98, and boils only at 883 ° C. Consequently, the temperature range of the liquid state of this element is quite large. That is why (and also due to the small neutron capture cross section) sodium began to be used in nuclear power engineering as a coolant. In particular, American nuclear submarines are equipped with power plants with sodium circuits. The heat generated in the reactor heats up the liquid sodium, which circulates between the reactor and the steam generator. In a steam generator, sodium, while cooling, evaporates water, and the resulting high-pressure bunk rotates a steam turbine. An alloy of sodium and potassium is used for the same purposes.
• INORGANIC PHOTOSYNTHESIS. Usually, when sodium is oxidized, an oxide of the composition Na 2 O is formed. However, if sodium is burned in dry air at an elevated temperature, then instead of the oxide, peroxide Na 2 O 2 is formed. This substance easily gives up its "extra" oxygen atom and therefore has strong oxidizing properties. At one time, sodium peroxide was widely used to bleach straw hats. Now specific gravity straw hats in the use of sodium peroxide is negligible; most of it is used for bleaching paper and for air regeneration in submarines. When sodium peroxide interacts with carbon dioxide, the process is reversed to respiration: 2Na 2 O 2 + 2CO 2 → 2Na 2 CO 3 + O 2, i.e. carbon dioxide binds and oxygen is released. Just like a green leaf!
• SODIUM AND GOLD. By the time No. 11 was discovered, alchemy was no longer honored, and the idea of ​​turning sodium into gold did not excite the minds of natural scientists. However, nowadays a lot of sodium is consumed in order to obtain gold. "Gold ore" is treated with a solution of sodium cyanide (and it is obtained from elemental sodium). In this case, gold is converted into a soluble complex compound, from which it is isolated with the help of zinc. Gold miners are among the main consumers of element 11. On an industrial scale, Na cyanide is obtained by the interaction of sodium, ammonia and coke at a temperature of about 800 ° C.
• SODIUM WIRES. The electrical conductivity of sodium is three times lower than the electrical conductivity of copper. But sodium is 9 times lighter! It turns out that sodium wires are more profitable than copper ones. Of course, thin wires are not made of sodium, but it is advisable to make tires for high currents from sodium. These tires are steel pipes welded from the ends, filled with sodium inside. Such tires are cheaper than copper ones.

• SODIUM IN WATER. Every student knows what happens if you throw a piece of sodium into water. More precisely, not into water, but into water, because sodium is lighter than water. The heat that is released when sodium reacts with water is enough to melt the sodium. And now a sodium ball is running through the water, driven by the evolving hydrogen. However, the reaction of sodium with water is not only dangerous fun; on the contrary, it is often useful. Sodium reliably removes traces of water from transformer oils, alcohols, ethers and other organic substances, and with the help of sodium amalgam (i.e., an alloy of sodium with mercury), you can quickly determine the moisture content of many compounds. Amalgam reacts with water much more calmly than sodium itself. To determine the moisture content, a certain amount of sodium amalgam is added to the sample of organic matter, and the moisture content is judged by the volume of released hydrogen.
• SODIUM BELT OF THE EARTH. It is quite natural that Na on Earth is never found in a free state - this metal is too active. But in the upper atmosphere - at an altitude of about 80 km - a layer of atomic sodium was found. At this altitude, there is practically no oxygen, water vapor, or anything at all with which sodium could react. Sodium was also detected by spectral methods in interstellar space.
• SODIUM ISOTOPES. Natural sodium consists of only one isotope with a mass number of 23. There are 13 known radioactive isotopes of this element, two of which are of significant scientific interest. Sodium-22, decaying, emits positrons - positively charged particles, the mass of which is equal to the mass of electrons. This isotope with a half-life of 2.58 years is used as a positron source. And the isotope sodium-24 (its half-life is about 15 hours) is used in medicine to diagnose and treat some forms of leukemia - a serious blood disease.

How sodium is obtained

A modern electrolyzer for sodium production is a rather impressive structure that looks like a furnace. This "stove" is made of refractory bricks and is surrounded by a steel casing on the outside. A graphite anode surrounded by an annular mesh - a diaphragm is introduced from below through the bottom of the electrolyzer. This mesh prevents sodium from entering the anode space where chlorine is evolved. Otherwise, element 11 would have burned out in chlorine. The anode, by the way, is also annular. It is made of steel. An obligatory accessory of the electrolyzer is two hoods. One is installed above the anode for collecting chlorine, the other above the cathode for removing sodium.

The electrolyzer is charged with a mixture of carefully dried sodium chloride and calcium chloride. This mixture melts at a lower temperature than pure sodium chloride. Usually electrolysis is carried out at a temperature of about 600 ° C.

The electrodes are fed D.C. voltage of about 6 V; Na + ions discharge at the cathode and metallic sodium is released. Sodium floats up and is discharged into a special collection (of course, without air access). Cl - chlorine ions are discharged at the anode and gaseous chlorine, a valuable by-product of sodium production, is released.

Usually the electrolyzer operates under a load of 25-30 thousand A, while 400-500 kg of sodium and 600-700 kg of chlorine are produced per day.

"THE MOST METAL METAL". This is sometimes called sodium. This is not entirely true: in the Mendeleev table, the increase in metallic properties occurs as one moves from right to left and from top to bottom. So in sodium analogues in the group - france, rubidium, cesium, potassium - metallic properties are more pronounced than sodium. (Of course, only chemical properties are meant.) But sodium also has a full range of "metallic" chemical properties. It easily donates its valence electrons (one per atom), always exhibits a valence of 1+, and has pronounced reducing properties. Sodium hydroxide NaOH is a strong alkali. All this is explained by the structure of the sodium atom, on the outer shell of which there is one electron, and the atom can easily part with it.

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

How to get sodium: the formula

Previously, sodium was obtained by reducing sodium carbonate. For 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 producing metallic sodium. For this, electrolysis of sodium chloride melt is carried out.

2NaCl -> 2Na + Cl 2

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

Many people are wondering how sodium can be obtained at home. As you can see, this is possible if you can reach the melting point of table salt (sodium chloride). Then dip two graphite electrodes into the melt and connect them to a direct electric current source.

How to get sodium hydroxide

Sodium reacts very violently with water with the formation of sodium hydroxide, the evolution of hydrogen and a large generation 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 = 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 = 2Na 2 O

Many students believe that sodium oxide can be obtained by the reaction of 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 = Na 2 O 2

How to get sodium acetate

Sodium acetate can be obtained using the neutralization reaction of sodium bicarbonate with acetic acid:

CH 3 COOH + NaHCO 3 = CH 3 COONa + H 2 O + CO 2

This chemical reaction 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, the solution obtained during the reaction is evaporated.

Thus, making sodium acetate at home is very easy. But it's even easier to go in and buy it from a store that sells chemicals since this substance is very cheap, and it is hardly worth tinkering with its self-production.

Sodium chloride: how to get

Sodium chloride can be obtained by carrying out a neutralization reaction of hydrochloric acid 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 = NaCl + H 2 O + CO 2

Under the name of sodium chloride is a well-known table salt.