Each chemical element can be considered in terms of three sciences: physics, chemistry and biology.In this article we will try as closely as possible to characterize the aluminum.This element, which is in the third group, and the third period, according to the periodic table.Aluminum - metal, which has an average reactivity.Also, it is possible to observe compounds amphoteric properties.The atomic mass of aluminum is twenty-six grams per mole.
physical characteristics of aluminum
Under normal conditions it is a solid.The formula is very simple aluminum.It consists of atoms (not united in the molecule), which are aligned with the help of a crystal lattice in the solid substance.Color aluminum - silver-white.In addition, it has a metallic luster, as well as any other substances of this group.The color of the metal used in the industry, can be different due to the presence of impurities in the alloy.This is a fairly lightweight metal.Its density was 2.7 g / cm3, i.e. it is approximately three times lighter than iron.In this he may assign except magnesium, which is even easier of the metal.The hardness of aluminum is quite low.In it he gives most metals.The hardness of the aluminum is only two Mohs.Therefore, for its amplification-based alloys of the metal added harder.
aluminum melting occurs at a temperature of just 660 degrees Celsius.And it begins to boil when heated to a temperature of two thousand four hundred fifty-two degrees Celsius.This is a very ductile and fusible metal.This physical characteristic of aluminum ends.I would also like to note that the metal has the best after silver and copper conductivity.
prevalence in nature
Aluminum specifications which we have just considered, quite common in the environment.It can be observed in the composition of many minerals.Element aluminum - fourth among the most abundant in nature.Its mass fraction in the earth's crust is almost nine percent.Major minerals which are present in the composition of its atoms is bauxite, aluminum oxide, cryolite.First - a rock that is composed of oxides of iron, silicon and the metal in question, are also present in the structure of the water molecule.It has a non-uniform coloring: gray fragments, reddish-brown or other colors, which depend on the presence of various impurities.Thirty to sixty percent of the breed - aluminum, photos of which can be seen above.It is also very common in nature mineral is alumina.
It alumina.Its chemical formula - Al2O3.He may have red, yellow, blue or brown.Its hardness on the Mohs scale is nine units.The varieties of corundum are famous sapphires and rubies, sapphire and padparadzha (yellow sapphire).
Cryolite - a mineral that has a complex chemical formula.It consists of the fluorides of aluminum and sodium - 3NaF • AlF3.It looks like colorless or gray stone with a low hardness - only three on the Mohs scale.In today's world it is synthesized artificially in the laboratory.It is used in metallurgy.
Also aluminum can be found in nature in clays, the main component of which are oxides of silicon and of the metal associated with the water molecules.In addition, the chemical element can be seen in the composition of nepheline, whose chemical formula is as follows: KNa3 [AlSiO4] 4.
Getting
features aluminum involves consideration of ways to synthesis.There are several methods.Aluminium production process takes place in the first three stages.The last of these is the procedure of electrolysis on the cathode and a carbon anode.To carry out such a process requires the alumina, as well as adjuvants, such as cryolite (formula - Na3AlF6) and calcium fluoride (CaF2).In order to occur the decomposition of dissolved alumina, it is necessary with the molten cryolite, calcium fluoride, and heated to a temperature of at least nine hundred fifty degrees centigrade, and then passed through a current of these substances in the eighty thousand amperes and voltage five-eight volts.Thus, because the process settle on the cathode aluminum and anode will collect oxygen molecules, which in turn is oxidized anode and convert it into carbon dioxide.Before performing this procedure, bauxite, which is mined in the form of aluminum oxide, previously cleaned of impurities, as well as the process of dewatering.
Aluminium production method described above is very common in the industry.There is also a method, invented in 1827 by F. Wohler.It is that aluminum can be extracted by a chemical reaction between its chloride and potassium.To carry out such a process can only be created special conditions of very high temperature and vacuum.Thus, one mole of chloride and an equal volume of potassium can be prepared one mole of alumina and three moles of potassium chloride as a byproduct.This reaction can be written in the form of this equation: AІSІ3 + 3K = AІ + 3KSІ.This method has not gained a lot of popularity in the industry.
Characteristics of aluminum in terms of chemistry
As mentioned above, this is a simple matter, which is made up of atoms that are not organized in the molecule.Similar structures are formed almost all metals.Aluminum has a relatively high reactivity and strong reducing properties.Chemical characterization of aluminum will begin with a description of its reactions with other simple substance, as will be described further interaction with complex inorganic compounds.
Aluminium and simple substances
This includes, primarily, oxygen - the most common compound on the planet.From his twenty-one percent of the Earth's atmosphere is.Reaction of this material with any other called oxidation or combustion.It usually occurs at high temperatures.But in the case of the oxidation of aluminum is possible in normal conditions - the so formed oxide film.If the metal is crushed, it will burn, giving off large amounts of energy as heat.For carrying out the reaction between aluminum and oxygen needed these components in a molar ratio of 4: 3, which will result in two portions of the oxide.
This chemical reaction is expressed in the following equation: 4AІ + 3O2 = 2AІO3.Also, the reaction may be aluminum with halogens which include fluorine, iodine, bromine and chlorine.The names of these processes is derived from the corresponding halogen: fluoridation, iodization, bromination and chlorination.This is the typical coupling reaction.
For example, here the interaction of aluminum with chlorine.Such a process can only occur in the cold.
So, taking two moles of aluminum and three moles of chlorine, resulting in two moles of the metal chloride.The equation for this reaction is as follows: + 2AІ 3SІ = 2AІSІ3.In the same way it is possible to obtain aluminum fluoride, bromide and iodide it.
the substance in question with sulfur reacts only when heated.For carrying out the interaction between the two compounds necessary to take them in molar proportions of two to three, and one portion of the sulphide formed of aluminum.Reaction equation has the form: 2Al + 3S = Al2S3.
Furthermore, at high temperatures, and the aluminum reacts with carbon to form a carbide, and nitrogen to form a nitride.One can cite as an example the following equations of chemical reactions: 4AІ + 3C = AІ4S3;2Al + N2 = 2AlN.
interaction complex substances
These include water, salts, acids, bases, oxides.With all of these chemicals aluminum reacts differently.Let's look in detail each case.
reaction with water
With the most common substance on earth complex aluminum reacts when heated.This occurs only when the preliminary removal of oxide film.The interaction of the amphoteric hydroxide is formed, and hydrogen is released into the air.Taking two of aluminum and six parts water to obtain hydroxide and hydrogen in the molar ratio of two to three.Writes the equation of this reaction is as follows: 2AІ + 6H2O = 2AІ (OH) 3 + 3H2.
reaction with acids, bases and oxides
Like other active metals, aluminum can react substitution.Thus it can displace the hydrogen from the acid or the cation of a passive metal salt thereof.As a result of these interactions an aluminum salt is formed, and hydrogen is released (in the case of acid) or precipitated metal net (the one that is less active than the reporting).In the second case and manifest reduction properties, which have been mentioned above.One example is the interaction of aluminum with hydrochloric acid, which is formed when the aluminum chloride and hydrogen is released into the air.This kind of reaction is expressed in the following equation: + 2AІ 6NSІ = 2AІSІ3 + 3H2.
example of the interaction of aluminum salt can serve his reaction with copper sulfate.Taking these two components, we end up with a pure aluminum sulfate and copper which fall in the form of a precipitate.With acids such as sulfuric and nitric acid, aluminum reacts peculiar.For example, adding a dilute solution of aluminum nitrate acid in a molar ratio of eight parts by thirty eight parts is formed of the metal nitrate, three parts nitric oxide and fifteen - water.The equation of the reaction is recorded thus: 8Al + 30HNO3 = 8Al (NO3) 3 + 3N2O + 15H2O.This process occurs only in the presence of heat.
If you mix aluminum and a weak solution of sulphate acid in a molar ratio of two to three, we get of the metal sulfate and hydrogen in a ratio of one to three.That is, ordinary substitution reaction occurs, as is the case with other acids.For clarity, we present the equation: 2Al + 3H2SO4 = Al2 (SO4) 3 + 3H2.However, with the concentrated acid solution of the same more difficult.Here, just as in the case of the nitrate, the by-product is formed, but not in the oxide form and in the form of sulfur and water.If we take our two necessary component in a molar ratio of two to four, the result is the one part of the metal salt and sulfur, and four - water.This chemical reaction can be expressed by the following equation: 2Al + 4H2SO4 = Al2 (SO4) 3 + 4H2O + S.Moreover, aluminum can react with alkalis.To carry out such chemical interactions need to take two moles of the metal, the same amount of sodium or potassium hydroxide, as well as six moles of water.This produces substances such as sodium or potassium tetragidroksoalyuminat and hydrogen, which is released as a gas with a pungent odor in molar proportions of two to three.This chemical reaction can be represented by the following equation: 2AІ + 2KOH + 6H2O = 2K [AІ (OH) 4] + 3H2.
And the last thing to consider is the patterns of interaction with some aluminum oxides.The most common and used case - reaction Beketov.It, as well as many others considered above, occurs only at higher temperatures.So, for its implementation need to take two moles per mole of aluminum oxide Ferrum.The interaction of these two substances are aluminum oxide and free iron in an amount of one and two moles respectively.
use of the metal in the industry
Note that the use of aluminum - a very common phenomenon.First of all, it needs the aviation industry.Along with magnesium alloy is used and based alloys of the metal.We can say that the average plane is 50% of the aluminum alloy, and its engine - 25%.Also, the use of aluminum is carried out during the manufacture of wires and cables because of its excellent electrical conductivity.Furthermore, the metal and its alloys are widely used in the automotive industry.These materials consist of carcasses of cars, buses, trolleybuses, trams some, as well as conventional and electric cars.Also it is used in smaller-scale applications, for example for the production of packaging for food and other products, glassware.In order to produce a silver paint is required of the metal powder.Such paint is needed in order to protect against corrosion of iron.It can be said that aluminum - the second most frequently used in industrial metals after Ferrum.Its compounds and he often used in the chemical industry.This is due to the specific chemical properties of aluminum, including its reducing properties it and amphoteric compounds.Hydroxide is a chemical element considered essential for water purification.In addition, it is used in medicine in the production of vaccines.It can also be found in the composition of certain types of plastic and other materials.
role in nature
As has been described above, aluminum in large quantities in the earth's crust.It is especially important for living organisms.Aluminum is involved in the regulation of growth, forming connective tissues, such as bone, ligamentous and others.With this trace elements will carry out the process of regeneration of body tissues.Its decline is characterized by the following symptoms: development and growth disorders in children, adults - chronic fatigue, reduced performance, impaired motor coordination, reduced rates of tissue regeneration, weakening of muscles, especially in the extremities.This phenomenon can occur if you eat too little food with the content of trace elements.
However, a more common problem is an excess of aluminum in the body.It is often observed symptoms: anxiety, depression, sleep disorders, memory loss, stress, softening of the musculoskeletal system, which can lead to frequent fractures and sprains.Prolonged excess aluminum in the body are often problems in virtually every organ system.
Such a phenomenon may cause a number of reasons.This is primarily aluminum cookware.Scientists have long shown that the dishes made of the metal in question, is not suitable for the preparation of food in it, since the high temperature of the aluminum enters the food, and as a result you eat a lot more of this trace element, than the body needs.
second reason - the regular use of cosmetics with the content of the metal or its salts.Before using any product you need to carefully read its composition.Is no exception and cosmetics.
third reason - taking medications that contain a lot of aluminum, for a long time.As well as the misuse of vitamins and nutritional supplements, which include the microcell.
Now let's see in which products contain aluminum, to regulate and organize your diet menu correctly.This primarily carrots, processed cheese, wheat and alum, potatoes.Because avocados are recommended fruits and peaches.In addition, the aluminum-rich cabbage, rice, many herbs.Also, the cations of the metal may be present in drinking water.To avoid high or low aluminum content in the body (though, just like any other trace elements), you need to carefully monitor their diet and try to make it more balanced as possible.
