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, we will consider the characteristics of sodium in terms of physics. To begin with, in its pure form it is a solid substance of silver 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 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 quickly and violently react with many other substances. Also, the table of chemical elements allows you to determine such a value as the molar mass - for sodium it is twenty-three. One mole is the amount of 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, it is possible to 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 is alkaline, respectively, its oxide can form alkali (strong bases).
How are oxides formed?
All substances of this group, including in the case of sodium, can be obtained by burning the original. Thus, the reaction of the metal with oxygen occurs, which leads to the formation of oxide. For example, if you burn four moles of sodium, we 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 + 2 = 2Na 2 O. If water is added 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, sodium hydroxide actively reacts with salts of inactive 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 hydroxide can easily destroy tissue, paper, skin, nails, so it requires compliance with safety precautions while working with it. Sodium hydroxide 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.
Halogen Reactions
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, 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 one mole of fluorine to it. As a result, we obtain sodium fluoride in an amount of two mol. This process can be written in the form of the equation: Na + F 2 = 2NaF. Sodium fluoride, which we received, is used in the production of anti-caries toothpastes, 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, which is used as a medicine for neurosis, insomnia, hysteria and other disorders of the nervous system, can be obtained.
With other simple substances
Sodium reactions with phosphorus, sulfurum (sulfur), carbon (carbon) are also possible. Such chemical interactions can only be carried out if special conditions are created in the form of high temperature. Thus, an addition reaction occurs. Using it, 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 in the form of the following equation: 3Na + P = Na 3 P. In addition, sodium is able to react with nitrogen, as well as with hydrogen. In the first case, nitride of this metal is formed, in the second - hydride. As examples, one can give the following equations of chemical reactions: 6Na + N2 = 2Na 3 N; 2Na + H2 = 2NaH. For the first interaction, an electric discharge is required, the second - high temperature.
Acid Reactions
On simple substances, the chemical characterization of sodium does not end there. This metal also reacts with all acids. As a result of such chemical interactions, a sodium salt and hydrogen are formed. For example, during the reaction of the metal in question 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 get 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 greater chemical activity than the element in question). In a similar case, as in the previous one, a substitution reaction occurs. The atoms of the metal in question replace the atoms of the more chemically weak metal. Thus, by mixing two moles of sodium and one mole of magnesium nitrate, we get sodium nitrate in an amount of two moles, as well as pure magnesium - one mole. The equation of 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 in this way you can get metals from their salts.
What happens if water is added to sodium
This is perhaps one of the most common substances on the planet. And with it, the metal in question is also able to enter into chemical interaction. In this case, sodium hydroxide, or sodium hydroxide, already considered 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 examined this metal from a chemical point of view, we turn to what is the biological characteristic of sodium. It is one of the important trace elements. First of all, it is one of the components of an animal cell. Here it performs important functions: together with potassium, it maintains the membrane potential, participates in the formation and distribution 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 transport of glucose through the blood is impossible, so necessary for the functioning of the brain. This metal also takes part in the process of muscle contraction.
This trace element 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 lack of sodium
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 be an increase in body temperature, swelling, increased nervous irritability, impaired renal function. In the event of the appearance of such symptoms, 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 consult a doctor immediately. A reduced sodium content in the body also leads to unpleasant symptoms and organ malfunctions. This chemical element can be washed out with long-term use of diuretic drugs or when drinking only purified (distilled) water, with increased sweating and dehydration of the body. Symptoms of sodium deficiency include thirst, dry skin and mucous membranes, vomiting and nausea, poor appetite, impaired consciousness and apathy, tachycardia, and the termination of the full functioning of the kidneys.
Foods High in Sodium
In order to avoid too high or too low levels in the body of the chemical element in question, you need to know which food contains it the most. First of all, this is the salt 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 observed in seafood. This is sea kale, 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 - for the separation of pure metals from their salts. There is special technical sodium intended for use for 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 family industry, where it is most often necessary 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 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 the latter from overgrowing. Sodium cyanide is widely used in the gold mining industry. With its help, this metal is obtained from rocks.
How to get sodium
The most common method is the reaction of the carbonate of the metal in question with carbon. For 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, such as sodium and sweet 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. 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 sodium ion is burning - if present, its flame will turn yellow.
Where can one meet the considered chemical element 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. For example, it is sylvinite, its formula is NaCl • KCl, and also 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, and blue can be found in its color red. This mineral is completely soluble in water. Carnallite, depending on the place of formation and impurities, can also have a different color. It can be red, yellow, white, light blue, and also transparent. It has a dim brilliance, the rays of light in it are strongly refracted. These two minerals serve as raw materials for the production of metals that make up their composition: sodium, potassium, and magnesium.
Scientists believe that the metal that 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.