Iron is a well-known chemical element. It belongs to the metals with average reactivity. We will consider the properties and use of iron in this article.
Prevalence in nature
There are a fairly large number of minerals that include ferrum. First of all, it is magnetite. It is seventy-two percent iron. Its chemical formula is Fe3O4. This mineral is also called magnetic iron ore. It has a light gray color, sometimes with dark gray, up to black, with a metallic sheen. Its largest deposit among the CIS countries is located in the Urals.
The next mineral with a high iron content is hematite - it is seventy percent of this element. Its chemical formula is Fe2O3. It is also called red iron ore. It has a color from red-brown to red-gray. The largest deposit in the territory of the CIS countries is located in Krivoy Rog.
The third mineral in terms of ferrum content is limonite. Here, iron is sixty percent of the total mass. It is a crystalline hydrate, that is, water molecules are woven into its crystal lattice,its chemical formula is Fe2O3•H2O. As the name implies, this mineral has a yellow-brownish color, occasionally brown. It is one of the main components of natural ocher and is used as a pigment. It is also called brown ironstone. The largest occurrences are Crimea, Ural.
In siderite, the so-called spar iron ore, forty-eight percent of ferrum. Its chemical formula is FeCO3. Its structure is heterogeneous and consists of crystals of different colors connected together: gray, pale green, gray-yellow, brown-yellow, etc.
The last naturally occurring mineral with a high ferrum content is pyrite. It has the following chemical formula: FeS2. 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 considered minerals are used to obtain pure iron. In addition, hematite is used in the manufacture of jewelry from natural stones. Pyrite inclusions can be found in lapis lazuli jewelry. In addition, iron is found in nature in the composition of living organisms - it is one of the most important components of the cell. This trace element must be supplied to 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 has a good effect on the state of the blood, and therefore the whole organism as a whole.
Iron: physical and chemical properties
Let's consider these two large sections in order. The physical properties of iron are its appearance, density, melting point, etc. That is, all the distinguishing features of a substance that are associated with 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. It has a silvery-gray color and a pronounced metallic sheen. The mechanical properties of iron include the level of hardness on the Mohs scale. It is equal to four (medium). Iron has good electrical and thermal conductivity. The last feature can be felt by touching an iron object in a cold room. Because this material conducts heat quickly, it absorbs most of it from your skin in a short amount of time, which is why you feel cold.
Touching, for example, a tree, it can be noted that its thermal conductivity is much lower. The physical properties of iron are its melting and boiling points. The first is 1539 degrees Celsius, the second is 2860 degrees Celsius. It can be concluded that the characteristic properties of iron are good ductility and fusibility. But that's not all.
Also, the physical properties of iron include its ferromagnetism. What it is? Iron, whose magnetic properties we can observe in practical examples every day, is the only metal that has suchunique distinguishing feature. This is due to the fact that this material is able to be magnetized under the influence of a magnetic field. And after the termination of the action of the latter, iron, the magnetic properties of which have just been formed, remains a magnet for a long time. This phenomenon can be explained by the fact that in the structure of this metal there are many free electrons that are able to move around.
From the point of view of chemistry
This element belongs to the 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 capable of reacting with many classes of substances.
Start simple
Ferrum interacts with oxygen, nitrogen, halogens (iodine, bromine, chlorine, fluorine), phosphorus, carbon. The first thing to consider is reactions 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 varied. As an example of such interactions, the following reaction equations can be given: 2Fe + O2=2FeO; 4Fe + 3O2=2Fe2O3; 3Fe + 2O2=Fe3O4. And the properties of iron oxide (both physical and chemical) can be varied, depending on its variety. These kinds of reactions occur at high temperatures.
Next - interaction with nitrogen. It can also only happensubject to heating. If we take six moles of iron and one mole of nitrogen, we get two moles of iron nitride. The reaction equation will look like this: 6Fe + N2=2Fe3N.
When interacting with phosphorus, a phosphide is formed. To carry out the reaction, the following components are necessary: for three moles of ferrum - one mole of phosphorus, as a result, one mole of phosphide is formed. The equation can be written as follows: 3Fe + P=Fe3P.
In addition, among the reactions with simple substances, one can also distinguish the interaction with sulfur. In this case, sulfide can be obtained. The principle by which the process of formation of this substance occurs is similar to those described above. Namely, an addition reaction occurs. All chemical interactions of this kind require special conditions, mainly high temperatures, less often catalysts.
Reactions between iron and halogens are also common in the chemical industry. These are chlorination, bromination, iodination, fluorination. As is clear from the names of the reactions themselves, this is the process of adding chlorine / bromine / iodine / fluorine atoms to ferrum atoms to form chloride / bromide / iodide / fluoride, respectively. These substances are widely used in various industries. In addition, ferrum is able to combine with silicon at high temperatures. Due to its diverse chemical properties, iron is often used in the chemical industry.
Ferrum and complex substances
From simple substances, let's move on to those whose molecules consist of two or morevarious chemical elements. The first thing to mention is the reaction of ferrum with water. Here are the main properties of iron. When water is heated together with iron, a basic oxide is formed (it is called so because when interacting with the same water it forms a hydroxide, in other words, a base). So, if you take one mole of both components, substances such as ferrum dioxide and hydrogen are formed in the form of a gas with a pungent odor - also in molar proportions of one to one. The equation for this kind of reaction can be written as follows: Fe + H2O=FeO + H2. Depending on the proportions in which these two components are mixed, iron di- or trioxide 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 s alts
Since ferrum is located to the left of hydrogen in the electrochemical series of activity of metals, it is able to displace this element from compounds. An example of this is the substitution reaction that can be observed when iron is added to an acid. For example, if you mix iron and sulphate acid (aka sulfuric acid) of medium concentration in the same molar proportions, the result will be ferrous sulfate (II) and hydrogen in the same molar proportions. The equation for such a reaction would look like this: Fe + H2SO4=FeSO4 + H 2.
When interacting with s alts, the reducing properties of iron appear. That is, with the help of it, a less active metal can be isolated from s alt. For example, iftake one mole of copper sulfate and the same amount of ferrum, then you can get iron sulfate (II) and pure copper in the same molar proportions.
Value for the body
One of the most common chemical elements in the earth's crust is iron. We have already considered the properties of matter, now we will approach it from a 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 such a protein as hemoglobin. It is necessary for the transport of oxygen through the blood from the lungs to all tissues, organs, to every cell of the body, primarily to the neurons of the brain. Therefore, the beneficial properties of iron cannot be overestimated.
In addition to the fact that it affects blood formation, ferrum is also important for the full functioning of the thyroid gland (this requires not only iodine, as some believe). Iron also takes part in intracellular metabolism, regulates immunity. Ferrum is also found in especially large quantities in liver cells, as it helps to neutralize harmful substances. It is also one of the main components of many types of enzymes in our body. The daily diet of a person should contain from ten to twenty milligrams of this trace element.
Foods rich in iron
There are many of them. They are of both plant and animal origin. The first are cereals, legumes, cereals (especially buckwheat), apples, mushrooms (porcini), dried fruits, rose hips, pears, peaches,avocado, pumpkin, almonds, dates, tomatoes, broccoli, cabbage, blueberries, blackberries, celery, etc. The second - liver, meat. The use of foods high in iron is especially important during pregnancy, as the body of the developing fetus requires a large amount of this trace element for proper growth and development.
Signs of iron deficiency
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, low performance, and thyroid disorders. If you notice more than one of these symptoms, you may want to increase the amount of iron-rich foods in your diet or buy vitamins or supplements containing ferrum. Also, be sure to see a doctor if you experience any of these symptoms too strongly.
Use of ferrum in industry
The uses and properties of iron are closely related. Due to its ferromagnetism, it is used to make magnets - both weaker for domestic purposes (souvenir fridge magnets, etc.), and stronger - for industrial purposes. Due to the fact that the metal in question has high strength and hardness, it has been used since ancient times for the manufacture of weapons, armor and other military and household tools. By the way, even in ancient Egypt, meteorite iron was known, the propertieswhich are superior to those of ordinary metal. Also, such a special iron was used in ancient Rome. They made elite weapons from it. A shield or sword made of meteoritic metal could only be owned by a very rich and noble person.
In general, the metal that we are considering in this article is the most versatile used among all the substances of this group. First of all, steel and cast iron are made from it, which are used to produce all kinds of products necessary both 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 there is about 0.02 percent carbon in the composition, then this is already ordinary technical iron. The presence of carbon in the alloy is necessary to give it greater strength, heat resistance, and rust resistance.
In addition, steel can contain many other chemical elements as impurities. This is manganese, and phosphorus, and silicon. Also, chromium, nickel, molybdenum, tungsten and many other chemical elements can be added to this kind of alloy to give it certain qualities. Types of steel in which a large amount of silicon is present (about four percent) are used as transformer steels. Those containing a lot of manganese (up to twelve or fourteen percent) find their application in the manufacture of partsrailroads, mills, crushers and other tools that wear parts quickly.
Molybdenum is introduced into the composition of the alloy to make it more thermally stable - such steels are used as tool steels. In addition, to obtain well-known and commonly used stainless steels in the form of knives and other household tools, 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. When introduced into the composition of niobium, it is possible to achieve high resistance to corrosion and the effects of chemically aggressive substances.
The mineral magnetite, which was mentioned at the beginning of the article, is needed for the manufacture of hard drives, memory cards and other devices of this type. Due to its magnetic properties, iron can be found in the construction of transformers, motors, electronic products, etc. In addition, ferrum can be added to other metal alloys to give them greater strength and mechanical stability. The sulfate of this element is used in horticulture for pest control (along with copper sulfate).
Iron chlorides are indispensable for water purification. In addition, magnetite powder is used in black and white printers. The main use of pyrite is to obtain sulfuric acid from it. This process occurs in the laboratory in three stages. In the first stage, ferrum pyrite is burned to produce iron oxide and sulfur dioxide. The second step is the conversion of the dioxidesulfur to its trioxide 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.
Getting iron
This metal is mainly mined from its two main minerals: magnetite and hematite. This is done by reducing iron from its compounds with carbon in the form of coke. This is done in blast furnaces, the temperature in which reaches two thousand degrees Celsius. In addition, there is a way to reduce the ferrum with hydrogen. This does not require a blast furnace. To implement this method, special clay is taken, mixed with crushed ore and treated with hydrogen in a shaft furnace.
Conclusion
The properties and uses of iron are varied. This is perhaps the most important metal in our lives. 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 are in many ways superior to the copper-tin alloy in terms of their physical properties, resistance to mechanical stress.
In addition, iron is more common on our planet than many other metals. Its mass fraction in the earth's crust is almost five percent. It is the fourth most abundant chemical element in nature. Also, this chemical element is very important for the normal functioning of the organism of animals and plants, primarily because hemoglobin is built on its basis. Iron is an essential micronutrientwhich is important for maintaining he alth and normal functioning of organs. In addition to the above, it is the only metal that has unique magnetic properties. It is impossible to imagine our life without ferrum.
