Chemical and physical properties of iron

Iron is a well-known chemical element. It refers to the average for the chemical activity of metals. The properties and applications of iron are discussed in this article.

Prevalence in nature

There is a fairly large amount of minerals, which include ferrum. First of all, it's magnetite. It is seventy-two percent iron. Its chemical formula is Fe ₃ O ₄ . This mineral is also called magnetic iron ore. It has a light gray color, sometimes with a dark gray, down to black, with a metallic luster. Its largest deposit among the CIS countries is in the Urals.

The next mineral with high iron content is hematite - it is seventy percent of this element. Its chemical formula is Fe ₂ O ₃ . It is also called red iron ore. It has a coloration from red-brown to reddish-gray. The largest field in the CIS is in Krivoy Rog.

The third mineral of the ferrum is limonite. Here iron is sixty percent of the total mass. This is crystalline hydrate, that is, water molecules are woven into its crystal lattice, its chemical formula is Fe ₂ O ₃ • H ₂ O. As the name implies, this mineral has a yellowish-brown color, occasionally brown. It is one of the main components of natural ocher and is used as a pigment. It is also called brown iron ore. The largest places are the Crimea, the Urals.

In siderite, the so-called spar iron ore, forty eight percent of ferrum. Its chemical formula is FeCO ₃ . Its structure is heterogeneous and consists of crystals of different colors joined together: gray, pale green, gray-yellow, brown-yellow, etc.

The latter is a naturally occurring mineral with a high content of pyrumite, pyrite. It has such a chemical formula of FeS ₂ . Iron in it is forty-six percent of the total mass. Due to the sulfur atoms, this mineral has a golden yellow color.

Many of the minerals considered are used to produce pure iron. In addition, hematite is used in the manufacture of jewelry from natural stones. Inclusions of pyrite can be found in adornments made of lapis lazuli. In addition, in nature, iron is found in living organisms - it is one of the most important components of the cell. This microelement must necessarily enter the human body in sufficient quantities. The healing properties of iron are largely due to the fact that this chemical element is the basis of hemoglobin. Therefore, the use of ferrum well affects the condition of the blood, and consequently, of the whole organism as a whole.

Iron: physical and chemical properties

Consider in order two of these large sections. The physical properties of iron are its appearance, density, melting point, etc. That is, all the distinctive features of matter that are related to physics. The chemical properties of iron are its ability to react with other compounds. Let's start with the first.

Physical properties of iron

In its pure form, under normal conditions, it is a solid substance. It has a silvery-gray color and a pronounced metallic luster. The mechanical properties of iron include the Mohs hardness level. It is equal to four (average). Iron has good electrical conductivity and thermal conductivity. The last feature can be felt by touching an iron object in a cold room. Since this material quickly conducts heat, it takes a large part of it out of your skin in a short period of time, and therefore you feel cold. Having touched, for example, to a tree, it can be noted that its thermal conductivity is much lower. The physical properties of iron are also its melting and boiling points. The first is 1539 degrees Celsius, the second - 2860 degrees Celsius. It can be concluded that the characteristic properties of iron - a good plasticity and fusibility. But even this is not all.

Also in the physical properties of iron is its ferromagnetism. What it is? Iron, whose magnetic properties we can observe on practical examples every day, is the only metal possessing such a unique distinctive feature. This is due to the fact that this material is able to magnetize under the action of a magnetic field. And after the termination of the last iron, the magnetic properties of which have just formed, remains itself a magnet for a long time. Such a phenomenon can be explained by the fact that in the structure of a given metal there are many free electrons that are able to move.

From the point of view of chemistry

This element refers to metals of medium activity. But the chemical properties of iron are typical for all other metals (except those that are to the right of hydrogen in the electrochemical series). It is able to react with many classes of substances.

Let's start with simple

Ferrum interacts with a kilo, nitrogen, halogens (iodine, bromine, chlorine, fluorine), phosphorus, carbon. The first thing to consider is the reaction with oxygen. When ferrum is burned, its oxides are formed. Depending on the conditions of the reaction and the proportions between the two participants, they can be diverse. As an example of this type of interaction, the following reaction equations can be cited: 2Fe + O ₂ = 2FeO; 4Fe + 3O ₂ = 2Fe ₂ O ₃ ; 3Fe + 2O ₂ = Fe ₃ O ₄ . And the properties of iron oxide (both physical and chemical) can be varied, depending on its variety. Such reactions occur at high temperatures.

The next is the interaction with nitrogen. It can also occur only on condition of heating. If we take six moles of iron and one mole of nitrogen, we get two moles of iron nitride. The reaction equation will be as follows: 6Fe + N ₂ = 2Fe ₃ N.

When interacting with phosphorus, a phosphide is formed. To carry out the reaction, such components are necessary: three moles of ferrule-one mole of phosphorus, resulting in the formation of one mole of phosphide. The equation can be written as follows: 3Fe + P = Fe ₃ P.

In addition, among reactions with simple substances, it is also possible to separate the interaction with sulfur. In this case, it is possible to obtain sulphide. The principle by which the process of formation of this substance occurs is similar to that described above. Namely, the addition reaction takes place. For all chemical interactions of this kind, special conditions are needed, mainly high temperatures, and less often catalysts.

Reactions between iron and halogens are also common in the chemical industry. This is chlorination, bromination, iodination, fluoridation. As is clear from the names of the reactions themselves, this is the process of addition of chlorine / bromine / iodine / fluorine atoms to the ferrum atoms to form chloride / bromide / iodide / fluoride, respectively. These substances are widely used in a variety of industries. In addition, the ferrum is able to combine with silicon at high temperatures. Due to the fact that the chemical properties of iron are diverse, it is often used in the chemical industry.

Ferrum and complex substances

From simple substances we proceed to those whose molecules consist of two or more different chemical elements. The first thing to mention is the reaction of the ferrum with water. Here, the basic properties of iron are manifested. When the water is heated together with iron, the basic oxide is formed (it is called so because it forms hydroxide when interacting with the same water, in other words - the base). So, if you take one mole of both components, substances such as ferric dioxide and hydrogen in the form of a gas with a sharp odor are formed, also in molar proportions of one to one. The equation of this kind of reaction can be written as follows: Fe + H ₂ O = FeO + H ₂ . Depending on the proportions in which these two components are mixed, di-or trioxide of iron can be obtained. Both of these substances are very common in the chemical industry, and are also used in many other industries.

With acids and salts

Since ferrum is located to the left of hydrogen in the electrochemical series of metal activity, it is able to displace this element from the compounds. An example of this is the substitution reaction, which can be observed by adding iron to the acid. For example, if one mixes iron and sulfate acid (the same sulfuric acid) in an average concentration, in the same molar proportions, as a result, we obtain ferrous sulfate (II) and hydrogen in the same molar proportions. The equation for this reaction would look like this: Fe + H ₂ SO ₄ = FeSO ₄ + H ₂ .

When reacting with salts, the reducing properties of iron are manifested. That is, with the help of it you can select a less active metal from salt. For example, if you take one mole of copper sulphate and the same amount of ferrum, you can get ferrous sulphate (II) and pure copper in the same molar proportions.

Importance for the body

One of the most common chemical elements in the earth's crust is iron. We have already examined the properties of matter , now we approach it from the biological point of view. Ferrum performs very important functions both at the cellular level and at the level of the whole organism. First of all, iron is the basis of a protein such as hemoglobin. It is necessary for the transport of oxygen by blood from the lungs to all tissues, organs, to every cell of the body, primarily to the neurons of the brain. Therefore, the useful properties of iron can not be overemphasized.

In addition to the fact that it affects blood formation, ferrum is also important for the proper functioning of the thyroid gland (this requires not only iodine, as some believe). Also, iron takes part in intracellular metabolism, regulates immunity. Still ferrum in an especially large amount is contained in the liver cells, since it helps to neutralize harmful substances. It is also one of the main components of many types of enzymes in our body. A person's daily diet should contain from ten to twenty milligrams of this trace element.

Products rich in iron

There are many such. They are both vegetable and animal. The first ones are cereals, legumes, cereals (especially buckwheat), apples, mushrooms (white), dried fruits, dog rose, pears, peaches, avocado, pumpkin, almonds, dates, tomatoes, broccoli, cabbage, blueberries, blackberries, celery and others. The second - the liver, meat. The use of foods with a high iron content is especially important during pregnancy, since the body of the fetus that is being formed requires a large amount of this trace element for full growth and development.

Signs of a deficiency in the body of iron

Symptoms of too little ferrum entering the body are fatigue, constant freezing of the hands and feet, depression, brittle hair and nails, decreased intellectual activity, digestive disorders, poor performance, abnormalities in the thyroid gland. If you notice several of these symptoms, then it is worth to increase the number of products with iron content in your diet or buy vitamins or food supplements containing ferrum. It is also necessary to consult a doctor if any of these symptoms you feel too keenly.

Use of ferrule in industry

The application and properties of iron are closely related. In connection with its ferromagnetism, it is used to make magnets - as weaker for domestic purposes (souvenir magnets for refrigerators, etc.), and for stronger ones - for industrial purposes. Due to the fact that the metal in question has high strength and hardness, it was used from antiquity for the manufacture of weapons, armor and other military and domestic tools. By the way, in ancient Egypt meteorite iron was known, the properties of which exceed those of ordinary metal. Also such special iron was used and in Ancient Rome. From it they made elite weapons. A shield or sword made of meteoric metal could only have a very rich and noble person.

In general, the metal, which we consider in this article, is the most versatile used among all substances of this group. First of all, it produces steel and cast iron, which are used to produce all kinds of products needed in industry and in everyday life.

Cast iron is an alloy of iron and carbon, in which the second is present from 1.7 to 4.5 percent. If the second is less than 1.7 percent, then this kind of alloy is called steel. If the carbon in the composition is present about 0.02 percent, then this is already ordinary technical iron. The presence of carbon in the alloy is necessary to give it greater strength, thermal stability, rust resistance.

In addition, the steel can contain many other chemical elements as impurities. This is manganese, and phosphorus, and silicon. Also in this kind of alloy to give it certain qualities can be added chromium, nickel, molybdenum, tungsten and many other chemical elements. Types of steel, in which there is a large amount of silicon (about four percent), are used as transformer. Those in which a lot of manganese (up to twelve or fourteen percent), are used in the manufacture of parts of railways, mills, crushers and other tools, some of which are prone to rapid erasure.

Molybdenum is incorporated into the alloy to make it more thermally stable - such steels are used as tool mills. In addition, to obtain all known and often used in the home in the form of knives and other household tools of stainless steels, it is necessary to add chromium, nickel and titanium to the alloy. And in order to get shock-resistant, high-strength, ductile steel, it is enough to add vanadium to it. With the introduction of niobium, it is possible to achieve high resistance to corrosion and chemically aggressive substances.

Mineral magnetite, which was mentioned at the beginning of the article, is needed for the manufacture of hard disks, memory cards and other devices of this type. Due to the magnetic properties, iron can be found in the device transformers, motors, electronic products, etc. In addition, ferrum can be added to alloys of other metals to give them greater strength and mechanical stability. Sulfate of this element is used in horticulture for pest control (along with copper sulfate). Chloride iron is essential for water purification. In addition, magnetite powder is used in black and white printers. The main way to use pyrite is to get sulfuric acid from it. This process takes place in the laboratory in three stages. In the first pyrite stage, the ferrule is burned, thereby obtaining iron oxide and sulfur dioxide. At the second stage, the conversion of sulfur dioxide to its trioxide takes place with the participation of oxygen. And at the final stage, the resulting substance is passed through water vapor in the presence of catalysts, thereby obtaining sulfuric acid.

Preparation of iron

In general, this metal is extracted from its two main minerals: magnetite and hematite. This is done by reducing the iron from its compounds by carbon in the form of coke. This is done in blast furnaces, the temperature in which reaches two thousand degrees on a scale of Celsius. In addition, there is a way to restore ferrum hydrogen. For this, the presence of a blast furnace is not necessary. To implement this method, take a special clay, mix it with crushed ore and process with hydrogen in a shaft furnace.

Conclusion

Properties and use of iron are diverse. This is perhaps the most important metal in our life. Having become known to mankind, he took the place of bronze, which at that time was the main material for the manufacture of all tools, as well as weapons. Steel and cast iron in many ways surpass the alloy of copper with tin in terms of their physical properties, resistance to mechanical stress.

In addition, iron on our planet is more common than many other metals. Its mass fraction in the earth's crust is almost five percent. This is the fourth most common chemical element in nature. Also, this chemical element is very important for the normal functioning of the body of animals and plants, primarily because it is based on hemoglobin. Iron is the most important microelement, the use of which is important for maintaining the health and normal functioning of organs. In addition to the above, this is the only metal that has unique magnetic properties. Without a ferrum it is impossible to imagine our life.