Characteristic of sodium. The formula of 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

In this section, the characteristics of sodium in terms of physics will be considered. To begin with, in its pure form, it is a solid substance of silvery color, which has a metallic luster and low hardness. Sodium is so soft that it can easily be cut with a knife. The melting point of this substance is rather low and is seventy-nine degrees Celsius. The atomic mass of sodium is also small, we'll 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 to define such value, as molar mass - for sodium it makes twenty three. One mole is an amount of matter containing 6.02 x 10 to 23 degrees of atoms (molecules, if the substance is complex). Knowing the molar mass of the element, you can determine how much the specific amount of mole of a given substance will weigh. For example, two moles of sodium weighs forty-six grams. As already mentioned above, this metal is one of the most chemically active, it belongs to 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 parent. 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. Sodium oxide formula - Na ₂ O. The reaction equation looks like this: 4Na + O ₂ = 2Na ₂ O. If water is added to the resulting substance, an alkali-NaOH is formed.

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, sodium hydroxide actively reacts with salts of low-activity metals, organic compounds, etc. During the interaction with salts, an exchange reaction occurs-a new salt and a new base are formed. A solution of sodium caustic can easily destroy tissue, paper, skin, nails, so it requires compliance with safety regulations while working with it. Sodium hydroxide is used in the 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 of the periodic system. Their list includes fluoride, iodine, chlorine, bromine. Sodium is able to react with all of them, forming compounds such as chloride / bromide / iodide / sodium fluoride. To carry out the reaction, you need to take two moles of the metal in question, add to it one mole of fluoride. As a result, we obtain sodium fluoride in an amount of two moles. This process can be written in the form of the equation: Na + F ₂ = 2NaF. The sodium fluoride that we got is used in the production of toothpastes against caries, as well as detergents for a variety of surfaces. Similarly, with the addition of chlorine, sodium chloride (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 can be obtained.

With other simple substances

Also possible are the reactions of sodium with phosphorus, sulfur (sulfur), carbon (carbon). Such chemical interactions can only be carried out if special conditions are created in the form of a high temperature. Thus, the addition reaction takes place. With its help, you can get such substances 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 under consideration and one mole of the second component, then heat them, then we 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 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 of such chemical equations are: 6Na + N2 = 2Na ₃ N; 2Na + H2 = 2NaH. To conduct the first interaction, an electrical discharge is necessary, the second - a high temperature.

Reactions with acids

On simple substances, the chemical characteristics of sodium do not end. This metal also reacts with all acids. As a result of such chemical interactions, a sodium salt and hydrogen are formed. For example, the reaction of the metal in question with hydrochloric acid produces a cooking salt and hydrogen, which evaporates. This reaction can be expressed by the reaction equation: Na + HCl = NaCl + H ₂ . This kind of chemical interaction is called the substitution reaction. With its carrying out, it is also possible to obtain salts such as phosphate, nitrate, nitrite, sulfate, sulfite, sodium carbonate.

Interaction with salts

Sodium reacts with salts of all metals, except potassium and calcium (they have more chemical activity than the element under consideration). In such a case, as in the previous one, a substitution reaction occurs. The atoms of the metal under consideration become replaced by atoms of a chemically weak metal. Thus, by mixing two moles of sodium and one mole of magnesium nitrate, we get sodium nitrate in the amount of two moles, and also pure magnesium - one mole. The equation of this reaction can be written as 2Na + Mg (NO ₃ ) ₂ = 2NaNO ₃ + Mg. By the same principle, many other sodium salts can be obtained. Also this method can produce metals from their salts.

What will happen if you add water to sodium

This, perhaps, is one of the most common substances on the planet. And with it, the metal in question is also capable of entering into a chemical interaction. In this case, the 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 the amount of two moles, and as a result we get two moles of hydroxide and one mole of hydrogen, which will separate as a gas with a sharp odor.

Sodium and its effect on organisms

Having considered this metal from a chemical point of view, let us proceed to what is the biological characteristic of 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 the membrane potential, participates in the formation and propagation between the cells of the nerve impulse, 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, transport through the blood of glucose, so necessary for the functioning of the brain, is impossible. Still this metal takes part in the process of muscle reduction.

This micronutrient is needed not only by the animal - sodium in the plant organism 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 lack of sodium

To the increased content of this chemical element in the body can lead to excessive salt intake for a long time. Symptoms of excess sodium can include increased body temperature, swelling, increased nervous excitability, impaired renal function. In case of appearance of such symptoms it is necessary to remove the salt and products containing a lot of this metal (the list will be given below), then immediately consult a doctor. A lower sodium content also leads to unpleasant symptoms and impaired body performance. This chemical element can be washed out with long-term use of diuretics or when drinking only purified (distilled) water, with increased sweating and dehydration of the body. Symptoms of lack of sodium are thirst, dry skin and mucous membranes, vomiting and nausea, poor appetite, impaired consciousness and apathy, tachycardia, cessation of full-fledged kidney function.

Products in which there is a lot of 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 what kind of food it is most. First of all, this is the above-mentioned kitchen salt. It is forty percent sodium. It can also be sea salt. In addition, this metal is contained in soy and soy sauce. A large amount of sodium is observed in seafood. This sea kale, most species of fish, shrimp, octopus, crab meat, caviar, crawfish, 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 the 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 separate 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 aforementioned strong reducing properties, sodium is widely used in metallurgy.

This chemical element also finds its application in the pharmaceutical industry, where it is most often needed to produce 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. Such a chemical compound, like sodium chlorate (NaClO ₃ ), destroys young plants, so it is used to remove those from the railway tracks to prevent the overgrowing of the latter. Sodium cyanide has been widely used in the gold mining industry. With its help receive this metal from rocks.

How to 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 these two substances to a temperature of about a thousand degrees Celsius. As a result, two chemical compounds are formed, such as sodium and gas. By reacting one mole of sodium carbonate with two moles of carbon, two moles of the desired metal and three moles of carbon monoxide are obtained. The equation of the reduced reaction can be written as follows: NaCO ₃ + 2C = 2Na + 3CO. 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 carrying out special chemical manipulations. A qualitative reaction to the sodium ion is combustion - in the presence of its presence, the flame will be colored yellow.

Where can we 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 part of some minerals. This is, for example, sylvinite, its formula is NaCl • KCl, as well as carnallite, whose formula is KCl • MgCl ₂ • 6H ₂ O. The first of them has a heterogeneous structure with alternating multi-colored parts, its color can be orange, pink, blue , Red. This mineral is completely soluble in water. Carnallite, depending on the place of formation and impurities, can also have a different coloring. It can be red, yellow, white, light blue, and also transparent. It has a soft glint, 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 their composition: sodium, potassium, magnesium.

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