Characteristics of sodium. Sodium formula

Chemical experiments multifaceted in their depth, complexity, and effectiveness. Remembering the most beautiful reactions, it is impossible to ignore the “pharaoh snake” or the interaction of snake venom with human blood. However, chemists go further, paying attention to more dangerous experiments, one of which is the reaction of water and sodium.

Potential for sodium

Sodium is an extremely active metal that interacts with many known substances. The reaction with sodium often proceeds violently, accompanied by significant heat release, inflammation, and sometimes even. Working safely with a substance requires a clear understanding of its physical and chemical characteristics.

Sodium is not very hard in structure. It has the following properties:

  • low density (0.97 g/cm³);
  • softness;
  • low fusibility (melt 97.81 °C).

In air, the metal quickly oxidizes, so it should be kept in closed containers under a layer of Vaseline or kerosene. Before experimenting with water, you should cut off a piece of sodium with a thin scalpel, remove it from the container with tweezers and thoroughly clean it of kerosene residues with filter paper.

Important! All tools must be dry!

When working with metal, it is necessary to wear special glasses, because the slightest careless step can lead to an explosion.

History of explosion research

For the first time, scientists from the Czech Academy of Sciences under the leadership of Pavel Jungvirt were faced with the need to study the reaction of water and sodium. on the detonation of sodium in water, known since the 19th century, was carefully analyzed and described.

The reaction of sodium with water involved immersion in plain water piece of metal and was ambiguous: flashes sometimes occurred, sometimes not. Later, it was possible to establish the reason: the instability was explained by the size and shape of the sodium piece used.


The larger the dimensions of the metal, the stronger and more dangerous the reaction between sodium and water became.

Time-lapse footage of the reaction showed that within five milliseconds of being immersed in water, the metal "" released hundreds of "needles." The electrons of the metal instantly escaping into the water lead to the accumulation of a positive charge in it: the repulsion of positive particles tears the metal apart, which is why “needles” appear. At the same time, the area of ​​the metal increases, which causes such a violent reaction.

During the reaction, an alkali is formed, which leaves a raspberry trail behind the piece of sodium. At the end of the experiment, almost all the water in the crystallizer will turn crimson.

Such a reaction requires the researcher to fully comply with safety measures: carry out the experiment wearing safety glasses, trying to stay as far as possible from the crystallizer. Even seemingly insignificant errors can lead to an explosion. Getting the slightest particle of sodium or alkali into your eyes is dangerous.

Attention! Do not try to repeat these experiments yourself!

Sodium is very active metal, which reacts with many substances. Reactions involving sodium can occur violently and produce significant heat. In this case, ignition and even an explosion often occur. For safe work with sodium, it is necessary to have a clear understanding of its physical and chemical properties Oh.

Sodium is a light (density 0.97 g/cm3), soft and fusible (melt 97.86° C) metal. Its hardness resembles paraffin or soap. In air, sodium oxidizes very quickly, becoming covered with a gray film, which consists of Na2O2 peroxide and carbonate, so sodium is stored in well-closed jars under a layer of anhydrous kerosene or oil.

A piece of sodium the right size cut without removing the metal from the kerosene, using a knife or scalpel. Sodium is removed from the jar with tweezers. All tools must be dry! After this, sodium is freed from kerosene residues using filter paper. In some cases, the metal is cleaned with a scalpel to remove the peroxide layer, since contact of peroxide with fresh sodium surface can lead to an explosion. Sodium should not be handled by hand. Sodium scraps are fused with low heat under a layer of kerosene.

Under no circumstances should dishes that contain sodium be washed with water - this can lead to an explosion with tragic consequences. Residues of sodium are eliminated by adding alcohol, only then can water be used.

It is necessary to wear safety glasses when working with sodium. Never forget what you are dealing with - an explosion can happen at the most unexpected and inopportune moment, and you need to be prepared for this.

Reaction of sodium with water

Fill the crystallizer 3/4 full with water and add a few drops of phenolphthalein to it. Drop a half-pea-sized piece of sodium into the crystallizer. The sodium will remain on the surface because it is lighter than water. The piece will begin to actively react with water, releasing hydrogen. From the heat of the reaction, the metal will melt and turn into a silvery droplet that will actively run along the surface of the water. At the same time, a hissing sound is heard. Sometimes the hydrogen that is released lights up with a yellow flame. Sodium vapor gives it this color. If ignition does not occur, the hydrogen can be ignited. However, pieces of sodium smaller than a grain of wheat are extinguished.

As a result of the reaction, an alkali is formed, which acts on phenolphthalein, so a piece of sodium leaves behind a raspberry trail. At the end of the experiment, almost all the water in the crystallizer will turn crimson.

2Na + 2H2O = 2NaOH + H2

The walls of the crystallizer must be free of grease and other contaminants. If necessary, they are washed with an alkali solution, otherwise sodium sticks to the walls and the crystallizer may crack.

The experiment should be carried out wearing a protective mask or safety glasses. During the reaction, keep a certain distance and do not lean over the crystallizer under any circumstances. Getting molten sodium or alkali splashes into your eyes can lead to virtually guaranteed blindness.

Source www.chemistry-chemists.com

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 examine the characteristics of sodium from a physical point of view. Let's start with the fact that in its pure form it is a solid substance. silver color, having 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 amounts to 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 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 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 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 is alkaline; accordingly, its oxide can form alkali (strong bases).

How oxides are formed

All substances in this group, including in the case of sodium, can be obtained by burning the source material. Thus, the metal reacts with oxygen, which leads to the formation of an oxide. For example, if we burn four moles of sodium, we will spend one mole of oxygen and get two moles of the oxide of this metal. The formula of 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 one mole of 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, sodium hydroxide reacts actively with salts of low-active metals, organic compounds etc. During interaction with salts, an exchange reaction occurs - a new salt and a new base are formed. A sodium hydroxide solution can easily destroy fabric, paper, skin, and nails, so it requires compliance with safety rules when working with it. Applicable in chemical industry as a catalyst, and also 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 periodic table. Their list includes fluorine, iodine, chlorine, bromine. Sodium is capable of reacting 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 and 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. The sodium fluoride we obtained is used in the production of anti-caries toothpastes, as well as detergents for a variety of 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 medicine for neuroses, insomnia, hysteria and other disorders of the nervous system.

With other simple substances

Reactions of sodium with phosphorus, sulfur (sulfur), and carbon (carbon) are also possible. This kind of chemical interaction can only be carried out if special conditions are created in the form high temperature. Thus, an addition reaction occurs. With its help, you can 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 you take three moles of the metal in question and one mole of the second component, then heat them, you get one mole of sodium phosphide. This reaction can be written in the form of the following equation: 3Na + P = Na 3 P. In addition, sodium can react with nitrogen as well as hydrogen. In the first case, a nitride of this metal is formed, in the second - a hydride. Examples include the following equations: chemical reactions: 6Na + N2 = 2Na 3 N; 2Na + H2 = 2NaH. The first interaction requires an electric discharge, the second requires high temperature.

Reactions with acids

The characteristics of sodium do 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 is formed kitchen salt and hydrogen, 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, and sodium carbonate.

Interaction with salts

Sodium reacts with salts of all metals except potassium and calcium (they are more chemically active than the element in question). In this case, as in the previous one, a substitution reaction occurs. Atoms of the metal in question take the place of 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. The equation for this reaction can be written as follows: 2Na + Mg(NO 3) 2 = 2NaNO 3 + Mg. Using the same principle, many other sodium salts can be obtained. This method can also 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 the metal in question is also capable of entering into chemical interaction with it. In this case, caustic sodium, or sodium hydroxide, already discussed above, is formed.

To carry out such a reaction, you will 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 is released in the form of a gas with a pungent odor.

Sodium and its effects on organisms

Having examined this metal from a chemical point of view, let’s move on to what kind of biological characteristics sodium It is one of the important microelements. First of all, it is one of the components of the animal cell. Here it performs important functions: together with potassium, it supports, participates in the formation and propagation of nerve impulses between cells, and 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, the transport of glucose 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 in the body of plants 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.

Excess and deficiency of sodium

Excessive salt consumption over a long period of time can lead to increased levels of this chemical element in the body. Symptoms of excess sodium may include increased body temperature, swelling, increased nervous excitability, and impaired renal function. If such symptoms appear, you need to remove table salt and foods containing a lot of this metal from your 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. Wash off this chemical element may occur with long-term use of diuretics or with 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 proper kidney function.

Foods High in Sodium

In order to avoid too high or too low content of the chemical element in question in the body, you need to know which food contains the most of it. First of all, this is the kitchen salt already mentioned above. It consists of forty percent sodium. It can also be sea salt. In addition, this metal is found in soybeans and soy sauce. Large amounts of sodium are found 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 important for the normal functioning of the body.

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 for such purposes. Its properties are recorded in GOST 3273-75. Due to the strong reducing properties mentioned above, sodium is widely used in metallurgy.

This chemical element also finds its use 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 them from railway tracks to prevent them from overgrowing. Sodium cyanide is widely used in the gold mining industry. With its help, this metal is obtained from rocks.

How do you get sodium?

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 specified substances to a temperature of about a thousand degrees Celsius. As a result of this, two such chemical compounds, like sodium and fumes. 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 for the above 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. A qualitative reaction to sodium ion is combustion - if it is present, the flame will be colored yellow.

Where can the chemical element in question be found in nature?

Firstly, 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; its color can include orange, pink, blue, and red. 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 dim sheen and light rays are strongly refracted in it. These two minerals serve as raw materials for the production of metals that are part of their composition: 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 in earth's crust is two and a half percent.

If you place a piece of sodium in water, you can cause a violent, often explosive reaction

Sometimes we learn something early in life and just take it for granted that this is the way the world works. For example, if you throw a piece of pure sodium into water, you can get a legendary explosive reaction. As soon as the piece gets wet, the reaction causes it to hiss and heat up, it jumps on the surface of the water and even produces flames. It's just chemistry, of course. But isn't there something else going on at a fundamental level? This is exactly what our reader Semyon Stopkin from Russia wants to know:

What forces drive chemical reactions, and what happens at the quantum level? Specifically, what happens when water reacts with sodium?

The reaction of sodium with water is a classic and has a deep explanation. Let's start by studying the progression of the reaction.

The first thing to know about sodium is that at the atomic level it has only one more proton and one more electron than the inert or noble gas neon. Noble gases do not react with anything, and this is due to the fact that they are all completely filled with electrons. This ultra-stable configuration collapses when you move one element further down the periodic table, and this happens to all elements that exhibit similar behavior. Helium is ultra-stable, and lithium is extremely chemically active. Neon is stable, but sodium is active. Argon, krypton and xenon are stable, but potassium, rubidium and cesium are active.

The reason is the extra electron.


The periodic table is sorted into periods and groups according to the number of free and occupied valence electrons - and this is the primary factor in determining the chemical properties of an element

When we study atoms, we get used to thinking of the nucleus as a hard, small, positively charged center, and the electrons as negatively charged points in orbit around it. But in quantum physics the matter does not end there. Electrons can behave like dots, especially if you shoot them with another high-energy particle or photon, but if left alone they spread out and behave like waves. These waves are capable of self-tuning in a certain way: spherically (for s-orbitals containing 2 electrons), perpendicularly (for p-orbitals containing 6 electrons), and further, up to d-orbitals (10 electrons each), f-orbitals ( to 14), etc.


The orbitals of atoms in the lowest energy state are at the top left, and as you move to the right and down the energies increase. These fundamental configurations control the behavior of atoms and intra-atomic interactions.

These shells are filled due to the fact that prohibits two identical (for example, electrons) from occupying the same quantum state. If an electron orbital is filled in an atom, then the only place where an electron can be placed is the next higher orbital. The chlorine atom will gladly accept the extra electron, since it only needs one to fill its electron shell. Conversely, the sodium atom will gladly give up its last electron, since it has an extra one, and all the others have filled the shells. That's why sodium chlorine works out so well: sodium donates an electron to chlorine, and both atoms are in an energetically preferred configuration.


Elements of the first group of the periodic table, especially lithium, sodium, potassium, rubidium, etc. lose their first electron much more easily than all others

In fact, the amount of energy required for an atom to give up its outer electron, or ionization energy, appears to be especially low in metals with one valence electron. From the numbers you can see that it is much easier to take an electron from lithium, sodium, potassium, rubidium, cesium, etc. than from any other element


A still from an animation demonstrating the dynamic interaction of water molecules. Individual H 2 O molecules have V-shape and consist of two hydrogen atoms (white) connected to an oxygen atom (red). Adjacent H2O molecules briefly react with each other through hydrogen bonds (blue-white ovals)

So what happens in the presence of water? You can think of water molecules as extremely stable - H 2 O, two hydrogens bonded to one oxygen. But the water molecule is extremely polar - that is, on one side of the H 2 O molecule (the side opposite the two hydrogens) the charge is negative, and on the opposite side it is positive. This effect is sufficient to cause some water molecules - on the order of one in several millions - to split into two ions - one proton (H +) and a hydroxyl ion (OH –).


In the presence of large numbers of extremely polar water molecules, one in every few million molecules will break down into hydroxyl ions and free protons, a process called

The consequences of this are quite important for things like acids and bases, for the processes of dissolving salts and activating chemical reactions, etc. But we are interested in what happens when sodium is added. Sodium, that neutral atom with one loose outer electron, ends up in the water. And these are not just neutral H 2 O molecules, these are hydroxyl ions and individual protons. First of all, protons are important to us - they lead us to the key question:

Which is energetically preferable? Have a neutral sodium atom Na along with a single proton H+, or a sodium ion that has lost an electron Na+ along with a neutral hydrogen atom H?

The answer is simple: in any case, the electron will jump from the sodium atom to the first individual proton that comes its way.


Having lost an electron, the sodium ion will happily dissolve in water, just as the chlorine ion does when it gains an electron. It is much more energetically favorable - in the case of sodium - for an electron to pair with a hydrogen ion

This is why the reaction occurs so quickly and with such an energy output. But that is not all. We have neutral hydrogen atoms, and, unlike sodium, they do not line up in a block of individual atoms bonded together. Hydrogen is a gas, and it goes into an even more energetically preferable state: it forms the neutral hydrogen molecule H2. And as a result, a lot of free energy is formed, which goes into heating the surrounding molecules, neutral hydrogen in the form of a gas, which leaves the liquid solution into the atmosphere containing neutral oxygen O 2.


A remote camera takes close-up views of the Shuttle's main engine during a test run at John Stennis Space Center. Hydrogen is the fuel of choice for rockets due to its low molecular weight and the abundance of oxygen in the atmosphere with which it can react

If you accumulate enough energy, hydrogen and oxygen will also react! This furious combustion releases water vapor and great amount energy. Therefore, when a piece of sodium (or any element from the first group of the periodic table) gets into water, an explosive release of energy occurs. All this occurs due to electron transfer controlled quantum laws the Universe, and the electromagnetic properties of the charged particles that make up atoms and ions.


Energy levels and wave functions of electrons corresponding to different states of the hydrogen atom - although almost the same configurations are shared by all atoms. Energy levels are quantized as multiples of Planck's constant, but even the lowest energy, the ground state, has two possible configurations depending on the ratio of electron and proton spins

So let's recap what happens when a piece of sodium falls into water:

  • sodium immediately donates an outer electron to water,
  • where it is absorbed by a hydrogen ion and forms neutral hydrogen,
  • this reaction releases a large number of energy, and heats up surrounding molecules,
  • neutral hydrogen turns into molecular hydrogen gas and rises from the liquid,
  • and finally, when sufficient quantity energy, atmospheric hydrogen enters into a combustion reaction with hydrogen gas.


Sodium metal

All of this can be explained simply and elegantly using the rules of chemistry, and that is how it is often done. However, the rules governing the behavior of all chemical reactions come from even more fundamental laws: the laws quantum physics(such as the Pauli exclusion principle, which governs the behavior of electrons in atoms) and electromagnetism (which governs the interaction of charged particles). Without these laws and forces there will be no chemistry! And thanks to them, every time you drop sodium in water, you know what to expect. If you haven’t figured it out yet, you need to wear protection, don’t touch the sodium with your hands, and move away when the reaction begins!