Each chemical element can be considered withpoint of view of three sciences: physics, chemistry and biology. And in this article we will try to characterize aluminum as accurately as possible. This is a chemical element that is in the third group and the third period, according to the periodic table. Aluminum is a metal that has an average chemical activity. Also in its compounds can be observed amphoteric properties. The atomic mass of aluminum is twenty-six grams per mole.
При нормальных условиях он представляет собой solid. The formula for aluminum is very simple. It consists of atoms (not combined into molecules), which are built with the help of the crystal lattice in a solid substance. The color of aluminum is silvery white. In addition, it has a metallic luster, like all other substances of this group. The color of aluminum used in industry may be different due to the presence of impurities in the alloy. This is a fairly light metal.
The melting of aluminum occurs at a temperature ofonly 660 degrees Celsius. And it boils when heated to a temperature of two thousand four hundred fifty two degrees Celsius. It is a very ductile and low-melting metal. The physical characteristics of aluminum does not end there. I would also like to note that this metal has the best electrical conductivity after copper and silver.
Aluminum, whose specifications wejust reviewed, quite often found in the environment. It can be observed in the composition of many minerals. The element aluminum is the fourth most common in nature. Its mass fraction in the crust is almost nine percent. The main minerals that contain its atoms are bauxite, corundum, cryolite. The first is rock, which consists of oxides of iron, silicon, and the metal in question, and water molecules are also present in the structure. It has a heterogeneous color: fragments of gray, reddish-brown and other colors, which depend on the presence of various impurities. From thirty to sixty percent of this rock is aluminum, the photo of which can be seen above. In addition, corundum is a very common mineral in nature.
This is alumina.Its chemical formula is Al2O3. It can be red, yellow, blue or brown. Its Mohs hardness is nine units. The varieties of corundum include the well-known sapphires and rubies, leucosapphires, and also padparadja (yellow sapphire).
Cryolite is a more complex mineral.chemical formula. It consists of aluminum and sodium fluorides - AlF3 • 3NaF. It looks like a colorless or grayish stone with low hardness - only three on the Mohs scale. In the modern world it is synthesized artificially in the laboratory. It is used in metallurgy.
Also aluminum can be found in nature incomposition of clays, the main components of which are oxides of silicon and the metal in question, associated with water molecules. In addition, this chemical element can be observed in the composition of nepheline, whose chemical formula is as follows: KNa3 [AlSiO4] 4.
Характеристика алюминия предусматривает consideration of methods for its synthesis. There are several methods. The production of aluminum in the first way occurs in three stages. The last of these is the procedure for electrolysis at the cathode and the carbon anode. Alumina is required for such a process, as well as excipients such as cryolite (formula: Na3AlF6) and calcium fluoride (CaF2). In order for the process of decomposition of aluminum oxide dissolved in water to occur, it is necessary to heat it together with molten cryolite and calcium fluoride to a temperature of at least nine hundred and fifty degrees Celsius, and then pass a current of eighty thousand amperes and a voltage of five degrees through these substances. eight volts. Thus, as a result of this process, aluminum will settle on the cathode, and oxygen molecules will collect at the anode, which, in turn, will oxidize the anode and convert it to carbon dioxide. Before carrying out this procedure, bauxite, in the form of which aluminum oxide is mined, is preliminarily purified from impurities, and also undergoes the process of its dehydration.
Aluminum production in the manner described aboveis very common in metallurgy. There is also a method invented in 1827 by F. Wohler. It lies in the fact that aluminum can be mined by a chemical reaction between its chloride and potassium. To carry out a similar process is possible only by creating special conditions in the form of very high temperature and vacuum. Thus, one mole of aluminum and three moles of potassium chloride as a by-product can be obtained from one mole of chloride and the same volume of potassium. This reaction can be written in the form of the following equation: АІСІ3 + 3К = АИ + 3КСІ. The specified method has not gained great popularity in metallurgy.
As mentioned above, this is a simple substance,which consists of atoms not combined into molecules. Similar structures form almost all metals. Aluminum has a sufficiently high chemical activity and strong reducing properties. The chemical characterization of aluminum will begin with a description of its reactions with other simple substances, and the interactions with complex inorganic compounds will be described below.
These include, first of all, oxygen -The most common compound on the planet. Twenty-one percent of it consists of the atmosphere of the earth. Reactions of this substance with any other are called oxidation, or burning. It usually occurs at high temperatures. But in the case of aluminum, oxidation is possible under normal conditions - this is how an oxide film is formed. If the metal is crushed, it will burn, releasing a large amount of energy in the form of heat. For the reaction between aluminum and oxygen, these components are necessary in a molar ratio of 4: 3, with the result that we get two parts of oxide.
This chemical interaction is expressed inthe following equation: 4АІ + 3О2 = 2АІО3. Aluminum can also be reacted with halogens, which include fluorine, iodine, bromine and chlorine. The names of these processes derive from the names of the corresponding halogens: fluoridation, iodination, bromination and chlorination. These are typical addition reactions.
For example, we give the interaction of aluminum with chlorine. This kind of process can only happen in the cold.
So, taking two moles of aluminum and three moles of chlorine,we obtain as a result two moles of chloride of the metal under consideration. The equation for this reaction is as follows: 2АI + 3СІ = 2АІСІ3. Aluminum fluoride, its bromide and iodide can be obtained in the same way.
The substance in question only reacts with sulfur.when heated. For the interaction between these two compounds, you need to take them in molar proportions of two to three, and one part of aluminum sulfide is formed. The reaction equation has the following form: 2Al + 3S = Al2S3.
In addition, at high temperatures aluminuminteracts with carbon to form carbide and with nitrogen to form nitride. It is possible to cite as an example the following chemical reaction equations: 4АI + 3С = АІ4С3; 2Al + N2 = 2AlN.
These include water, salts, acids, bases, oxides. With all these chemical compounds, aluminum reacts differently. Let's take a closer look at each case.
With the most common on Earth difficultsubstance aluminum interacts when heated. This happens only in the case of preliminary removal of the oxide film. As a result of the interaction, amphoteric hydroxide is formed, and hydrogen is released into the air. Taking two parts of aluminum and six parts of water, we get two to three hydroxide and molar proportions. The equation for this reaction is written as: 2AI + 6H2O = 2AI (OH) 3 + 3H2.
Like other active metals, aluminum is capable ofenter substitution reaction. At the same time, it can displace hydrogen from an acid or a cation of a more passive metal from its salt. As a result of such interactions, an aluminum salt is formed, and hydrogen is released (in the case of an acid) or pure metal is precipitated (one that is less active than the one under consideration). In the second case, and restorative properties, which were mentioned above. An example is the interaction of aluminum with hydrochloric acid, in which aluminum chloride is formed and hydrogen is released into the air. A similar kind of reaction is expressed as the following equation: 2АI + 6СІ = 2АІСІ3 + 3Н2.
An example of the interaction of aluminum with salt canserve its reaction with copper sulfate. Taking these two components, we will end up with aluminum sulfate and pure copper, which will precipitate as a precipitate. With acids such as sulfuric and nitric, aluminum reacts in a peculiar way. For example, when aluminum is added to a dilute solution of nitrate acid in a molar ratio of eight parts to thirty, eight parts of the metal under consideration are formed, three parts of nitric oxide and fifteen are water. The equation for this reaction is written as follows: 8Al + 30HNO3 = 8Al (NO3) 3 + 3N2O + 15H2O. This process occurs only in the presence of high temperature.
If you mix aluminum and a weak solutionsulfate acid in molar proportions of two to three, then we obtain the sulfate of the metal in question and hydrogen in the ratio of one to three. That is, an ordinary substitution reaction will occur, as is the case with other acids. For clarity, we present the equation: 2Al + 3H2SO4 = Al2 (SO4) 3 + 3H2. However, with a concentrated solution of the same acid all the more difficult. Here, just as in the case of nitrate, a by-product is formed, but not in the form of oxide, but in the form of sulfur, and water. If we take the two components we need in a molar ratio of two to four, then as a result we will get one part of the salt of the metal and sulfur under consideration, as well as four parts of water. This chemical interaction can be expressed using the following equation: 2Al + 4H2SO4 = Al2 (SO4) 3 + S + 4H2O.
And the last thing to consider ispatterns of interaction of aluminum with some oxides. The most common and used case is Beketov’s reaction. It, as well as many of the others discussed above, occurs only at high temperatures. So, for its implementation it is necessary to take two moles of aluminum and one mole of ferrum oxide. As a result of the interaction of these two substances, we obtain aluminum oxide and free iron in quantities of one and two mol, respectively.
Note that the use of aluminum is very frequent.phenomenon. First of all, the aviation industry needs it. Along with magnesium alloys, alloys based on the metal in question are used here. We can say that the average aircraft is 50% made of aluminum alloys, and its engine is 25%. Also, the use of aluminum is carried out in the process of making wires and cables due to its excellent electrical conductivity. In addition, this metal and its alloys are widely used in the automotive industry. These materials consist of car, bus, trolleybus cases, some trams, as well as conventional and electric train cars.
As it was already written above, aluminum in largeamount contained in the crust. It is especially important for living organisms. Aluminum is involved in the regulation of growth processes, forms connective tissues, such as bone, ligamentous and others. Thanks to this trace element, the processes of regeneration of body tissues are carried out faster. Its shortage is characterized by the following symptoms: impaired development and growth in children, in adults - chronic fatigue, reduced performance, impaired coordination of movements, reduced rates of tissue regeneration, muscle weakening, especially in the limbs. Such a phenomenon may occur if you consume too few foods with the content of this trace element.
Однако более частой проблемой является избыток aluminum in the body. At the same time, the following symptoms are often observed: nervousness, depression, sleep disturbances, loss of memory, stress resistance, softening of the musculoskeletal system, which can lead to frequent fractures and sprains. With a prolonged excess of aluminum in the body, problems often arise in the operation of virtually every organ system.
This phenomenon can lead to a number of reasons.First of all it is aluminum tableware. Scientists have long proved that dishes made from the metal in question are unsuitable for cooking food, because at high temperatures, some of the aluminum gets into the food, and as a result, you consume much more of this trace element than your body needs.
The second reason is regular use.cosmetics with the content of the metal in question or its salts. Before using any product, you should carefully read its composition. Cosmetics are no exception.
Третья причина - прием препаратов, в которых contains a lot of aluminum for a long time. As well as the misuse of vitamins and nutritional supplements, which include this trace element.
Now let's see what productscontains aluminum to adjust your diet and organize the menu correctly. First of all, it is carrots, processed cheeses, wheat, alum, potatoes. Avocados and peaches are recommended. In addition, white cabbage, rice and many medicinal herbs are rich in aluminum. Also, the cations of the metal in question may be contained in drinking water. To avoid high or low aluminum content in the body (however, just like any other trace element), you need to carefully monitor your diet and try to make it as balanced as possible.
